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CarJunky AutoAdvice

2005 Envoy 4.2 Oil Pressure Low (DIC)

Showing 4 out of 25 Posts | Show 21 Hidden Posts
Question From MarineGrunt on 2005 Envoy 4.2 Oil Pressure Low (DIC)

2005 GMC Envoy XL 4.2 4WD

I just changed the thermostat. Got it all back together and let it warm up to get the coolant to the proper level. Not the dic is saying that the oil pressure is low and to shut down the engine. The oil pressure gauge reads zero.

I removed the alternator in order to make it easier to get to the thermostat. Are there any wires or harnesses I could have bumped or pinched that could relate to this? The alternator and thermostat are over by the under hood fuse box so I guess a wire could be a possibility. If not, is there a way to test the oil pressure sender or the stepper motor?

I guess I should have added that the oil was changed about 500 miles ago and is at the proper level.

Thanks!

Response From Hammer Time

MG, have you found the oil pressure sender?

Response From MarineGrunt

After posting and waiting for replies I sprayed down some of the coolant that was around the engine from the t stat replacement and dried it with air just to clean everything up. I started it back up and everything is fine. Gauge is reading normal and no more warning on the dic.
On alldata there's an oil pressure sensor that's located by the filter. It also lists an oil pressure sender but doesn't have any diagrams or repair information. It does list a part number and price though. Not sure what the deal is there.
If the stepper motor is bad would that cause the dic to warn you or is both the stepper motor and the dic sent information via the sender or sensor? I've heard that stepper motors are a known problem but don't know if that would trigger the dic to give a warning. I wouldn't think it would so if it happens again would it likely be the sensor?

Response From MarineGrunt

I did find the sender HT. It's right above the oil filter. There wouldn't be another one, would there?

Finally had time to dig in deeper. I checked pressure with a gauge. At idle it reads about 16 psi. At around 1200 rpm's I'm getting about 35 psi. Alldata says 12 psi minimum at 1200 rpm's. Obviously it isn't low but what is the ideal psi? What is considered too high? I took the above readings when the engine was at normal operating temps. When I first started the engine, and it was cold, pressure was 76 psi. It was sitting in my garage overnight and all day so the engine was freezing cold at start up. I guess non of that matters since the reading is taken at normal operating temp.

There is a little oil seepage that looks to be running down the filter. The oil sender is right above the filter. When I took the electrical connector off it looked like there was some oil inside the sender. I don't think the filter is leaking but rather the sender. I guess with oil inside the electrical connector it has to be.

I guess I mainly want to know how the readings look. I've never had to check oil pressure so just wondering if a reading can be too high.

Thanks!

Response From Hammer Time

Those pressures sound fine MG. I'd probably throw a new sender at it and see what happens.

Response From MarineGrunt

It was sitting in my garage overnight and all day so the engine was freezing cold at start up.

Not that it matters but that should've said the engine WASN'T freezing cold.

Since I now know engine oil pressure is good I went ahead and ordered an AC Delco sender online. It's cheaper online than from the local parts stores.

Thanks for the help. I'll post the results after I get it, install it, and drive it for a few days to make sure the problem is solved.




Response From Hammer Time

Hey, you happy about your new coach?

Response From MarineGrunt

You know, I am happy with their choice. Fox has never been that coach that I really like but he isn't one I don't like. You know what I mean. There are those coaches you can't stand. Normally the Bears pick up some guy that has never been a head coach or even in the NFL because they're too cheap. Fox has quite a bit of experience and has been around the league for a long time. Really, the Bears should've been better than what they were. If you look at their receivers, Forte, and even Cutler they should've won more games than they did. Look how Cutler did in Denver. There's no reason he can't play the same in Chicago. I think they just need to find an offense that suits him. Hopefully Fox can get the D back on track and help Cutler pull his head out of his backside. Cutler's main problem is his arrogant attitude. I can't stand him for that. I say give Fox a couple years. If he doesn't perform it's time to bring Ditka back! Then again, Fox has a better when % than Ditka. I just grew up with Ditka as coach so I've always liked him. He did awful with the Saints though.

Response From Hammer Time

Isn't Fox the guy that chased Cutler out of Denver?

Response From Double J

No, that was Josh Mcdaniels

Hopefully he can come here and chase him out of town again...

Response From Double J

Matter of fact, He'd look better in a Dolphins uniform.

Response From MarineGrunt


Hopefully he can come here and chase him out of town again...



No kidding. I don't know why they even resigned him. Heck, I'd rather go back to getting a new starter every year or two like usual. As many starting QB's as we've had you would think we'd eventually run across a good one. Even if they did they'd probably end up trading him for like a 4th round draft pick though. I know we've had some okay QB's but have we ever had a great QB? If so it was before my time.


I like Double J's idea. Let's put him in a Dolphin's uniform. We can then bug HT's house on Sundays so we can listen to him cuss and throw chairs around the place.

Response From Double J

Yeah, we've had so so QB's at best. McMahon was average but he was such a character that people think he was great.
He won because of the defense .
The only one that was close to any good was Sid Luckman.
As Bears fans , all we have to hang our hats on are the 85 Bears.Thank God for them..
Halas would have a fit if he came back and saw what they've done to this team.

I would love to see Ditka in his hey day have Cutler on his team, He would beat the shit out of him.


I like Double J's idea. Let's put him in a Dolphin's uniform. We can then bug HT's house on Sundays so we can listen to him cuss and throw chairs around the place.
Who, mild mannered Desi ?....LOL...
That would be worth the price of admission.

Response From Hammer Time

My neighbors have no doubt who my team is. Remember, around here the doors and windows are usually open in the winter.

Response From MarineGrunt

How did I know we were going to get that warm weather rubbed in our face....There's just no comeback for that one. The only thing I can hold onto is that even if I have 0 degree weather here I usually have 10+ degrees on Double J. Maybe more if the wind is whipping off of lake Michigan.

Response From Double J





How did I know we were going to get that warm weather rubbed in our face....There's just no comeback for that one. The only thing I can hold onto is that even if I have 0 degree weather here I usually have 10+ degrees on Double J. Maybe more if the wind is whipping off of lake Michigan.
Oh Yeah, you knew that was coming......LOL
Around here, you better not leave anything open, doors,windows, hell not even your fly.....they'll steal your eyeballs and maybe your balls

Response From Discretesignals

Hey, nothing like going camping at Fort Desoto and leaving your window down on your station wagon that was full of food. Then coming out the next morning to find the raccoons had a party inside along with raccoon crap everywhere, including the wiper cowling.

Response From Tom Greenleaf Top Rated Answer

LOL, MG - Of course they must brag that they can leave doors and windows open for Winter because they don't want to mention the whole rest of the year they are cowering for their life from man eating bugs, humidity that you can cut so take a swim and get stung or bitten by some newfangled protected species of something that could eat thru a space shuttle's heat tiles.


Cold for a few months doesn't sound so bad sometimes. Just kidding all around, Tom

Response From Hammer Time

Tom, you should get some help for the phobia you have about tropical life. I'm not bothered with any of those things. I saw more mosquitos up north than I see here, but them I don't hang out in the bushes at night.

Response From Double J


they are cowering for their life from man eating bugs


I remember years ago my folks went down to Sanibel
The first day there there were eaten alive by the NoSeeUm bugs / sand flies......
Ruined their trip..nobody had warned them about those things so they didn't know to use anything to prevent that.

Response From Hammer Time

Well, I do have to put the heat on sometimes when it drops into the low sixties during the day.

Response From Hammer Time

No, thank you

Response From Tom Greenleaf

Oil inside plug to sensor! Send that one to the circular file.
76PSI oil pressure? Was that just a split second spike or what? It shouldn't be able to go and stay that high no matter what?


T

Response From Tom Greenleaf

I am NOT coming up with credible info - sorry. I think this should be a three wire plug in that fits many GM vehicles. Wire colors should be a black w #s on it? beige one, and a light blue.
(edit - pic didn't show but this was where I looked,
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Oil-Pressure-Switch-Connector/_/R-ECHEC89_0334769523 )



Dang pic better show^^^^


Pigtail in stock at NAPA and Autosnooze's site shows a screw in (would expect that) but very old type gauge with a dome then a plug that wouldn't fit so screw that.


This just can't be NO oil pressure without obvious problems right now so it must have wires where you were working.
Guess I'd go back and look with alternator back off if anything got squished? Otherwise left to wild guessing for location, down rear under but visible by intake manifold or near oil filter? No clue why info is so lousy on this? Tom

Response From Tom Greenleaf

I didn't find location for the switch/sender but if really ZERO you know it would sound it and seize in no time so it must be wrong, disconnected or pinched as you suspect. Where wires are run I'll never know for sure but would check pressure manually at least to verify it's fine until you find where it's broken and doubt switch itself if just happened with the recent work.


Stay warm buddy! Tom

A couple different codes..B0100 and P0128

Showing 4 out of 41 Posts | Show 37 Hidden Posts
Question From MarineGrunt on A couple different codes..B0100 and P0128

2003 GMC Sierra 4X4 4.8L 91K

First off I got the P0128 and scanner says "Coolant Thermostat (Coolant Temp Below Thermostat Regulating Temperature). I replaced the thermostat a few days ago and cleared the code. I did notice that the engine temp only registered around 175 or so after that. The CEL came back on today and got the above code. I had the same issue with the Envoy even after replacing 2 thermostats. I ended up having to use an OEM thermostat and that took care of the problem. What are the chances this could also need OEM? My scanner does read some live data so do I need to see what the scanner says for engine temp in order to rule out the temp sender?

The airbag light also came on today. I got the code B0100 Scanner says "Electronic Front End Sensor 1 Performance". When I purchased the truck last August and it had the airbag light on. It ended up being the front passenger sensor and it was replaced. Any idea what sensor is faulty or will I have to take the truck to the dealership?

Thanks for any help.

Response From Hammer Time

It sounds like you answered your own question on the P0128. The Airbag code means the control module is not communicating with the front end sensor, probably a bad sensor but could be wiring too.

Response From MarineGrunt

I've never had to deal with a temp sender on any vehicle so I figured I'd double check with you. If I never would've joined this forum I wouldn't have had any idea of what to do after the thermostat didn't fix the problem. It's amazing how much you guys have taught me about problems I've yet to encounter on my own vehicles and it's just from browsing through different threads. Seems like I learn something new everyday. I'm going to have to start giving you guys my GI Bill!

Have you had any experience with the Dorman sensors? I can get one on ebay for around $50 versus over $200 for the OEM. Like I mentioned when I first posted, the passenger side was replaced last August. I just let the dealer do that one since I already had them looking into that clunking/chirping problem I had with the slip yoke. Think I should just pay the $45 to have them tell me what sensor it is or what the problem is? I'm kind of thinking since the passenger side has been replaced it's more than likely the driver's side. Awhile back I left my window down and got a bunch of rain on the floorboard. That triggered the airbag light too but it brought up a different code so that kind of had me thinking it's possibly a sensor. I have no clue though. I hate gambling on parts but since the part costs the same as the diagnosis, and it's likely the cause, I may just give it a try first. If it's not it I could always throw it back on ebay and probably get most of my money back.

What would you do if you were in my shoes?

Response From Hammer Time

$200 for a temp sensor? What is it..........solid gold?
OK, I re-read your post and I assume you referred to the crash sensor for that price.

You can easily check the temp sensor with the scan tool by just looking before starting the vehicle in the morning and compare the reading of the IAT and the ECT and they should match.

As for the crash sensor, I've really never dealt with any failure there which make me surprised you had 2. That makes me wonder what this truck has been through to need two of them.

I use a lot of Dorman stuff and although it is definitely lower quality than OEM, it's usually good enough. I don't know about this situation though. A crash sensor is a different story.

Response From MarineGrunt

I'll check the reading of the IAT and ECT and see if they match. Thanks for that info. I had no idea about that.

Crash sensor is $200 for OEM. $50 for Dorman.

I know the truck was originally from Wisconsin so maybe it was due from all the salt they use on the road. Just a thought though. It doesn't seem like the truck has been through anything crazy such as a flood. It has the normal rocker panel rust but nothing crazy. (I'm actually in the process of welding new on now. Passenger side is almost done.) I've had the carpet pulled up and no rust there. I've also had a handful of wiring harness unhooked and no corrosion or anything. The truck has a little bit of rust on the a-arms and some on the frame but nothing crazy. It has a clean title but I know that always doesn't mean anything.

I'm getting ready to leave to take my daughter up to Six Flags Great America in Chicago so I'll be sure to hook the scanner up in order to check the IAT and ECT. I think I'll also go ahead and roll the dice on the Dorman crash sensor. If that doesn't take care of it I'll probably have the dealer diagnose it and fix it on my own if I can.

I'll post back once I find anything out.

Thanks HT.

Response From MarineGrunt

At startup the IAT and EXT were 20° off. Does that mean temp sensor is bad?

Response From Hammer Time

It means one of them is, probably the CTS since you have a P0128

Response From MarineGrunt

Is there a way to test the cts?

Response From Hammer Time

You're already done the most reliable test. You can do a resistance test working off a chart but the accuracy leaves a lot to be desired. It should be a $25 sensor. I'd just replace it and do the comparison again.

Response From Tom Greenleaf

MG - if you have enough troubles it can be tested as HT said to verify it. If you don't have something yet for instant temp sensing I endorse and own this widget from Radio Shack. Small and accurate - not expensive and a wide temp range.

I've done the battle - shop to a kitchen for heat(stove/oven) or cold of freezer crap.

Small can be a good thing sometimes as it is so portable. It's exactly 4" long. This thing......

If that pic doesn't show I'm going to have a fit!

Thttps://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcTPfs-cE6Kx3BrUunAUqpFkplMD9ydgw2mQdh46uujfQuR8sMSW

Response From MarineGrunt

Thanks guys.....

Just rolled in the drive from the trip to Great America in Chicago. Man am I beat. We were waiting in line before they opened and closed it down. My body can't take those rides like I use to. I still love em though! My 10 year old daughter is fearless on all of those coasters.

I ordered the crash sensor off of ebay today. It was right around $52 shipped. I think it'll be here by Wednesday. I plan on picking up the cts tomorrow. I'll let you know if it takes care of it.

Response From Double J

MG, Just curious,how long does it take you to drive up there?

Guessing you're about 3 hours one way?

Response From MarineGrunt

I live in Metamora and it's right around a 3 hour drive to Gurnee. It's about 170 miles. Chicago is about a 140 mile drive. Being from down here I'm not use to tolls. I blew through one on the way. On the way home I had money ready and was making sure to pay attention. Of course, right when the toll was coming up my daughter started flapping her jaws. I ended up driving through an I-pass lane so had to skip that one too. They say you're allowed two "skips' every 24 months. Last year when we bought the Envoy I accidently blew through two of them. I was in my truck this time so I think I'm good since I can blame it on my wife. I guess I could just get online and pay the $1.40 and $1.90. Problem is I don't know what toll stations I went through. I hate how it branches off to like 300 lanes and you have to make sure you're in the right one. If you're paying attention 1/2 mile before it's no big deal. But, when you have a 10 year old girl talking your ear off it's an easy thing to miss!

When I use to go to more Bear's games about 8 years ago I would always take an exit around Cicero to swing by a meat locker. I believe it was owned by either a Polish or a Czech family. Seems like every worker was either Polish or Czech and had about 10-15 people working behind the counter. Most were young females probably in there 20's. They all had an accent. This place had glass displays full of meat probably 100' long! Well, maybe not quite but it was huge. It also had a lot of grocery items. It was a decent sized place. Seems like I remember them having a few hundred different kinds of sausages hanging behind the counter. I'd always stock up on these sausage breakfast links. They were about 6" long and about as big around as a handle of a screwdriver. That place was awesome. I can't remember its exact location but do remember a big red sign that said "Meat" or "Meat Market". I wish time would've allowed for us to stop by there yesterday.

Response From Hammer Time

Being from down here I'm not use to tolls. I blew through one on the way.


Yeah, I saw your picture on CNN.

Response From Tom Greenleaf

Tolls: Blew thru one myself that did the same thing. Just changed such that you get to a point of no chance to move over to where you can just pay. Now you don't even slow down or see anything - no booths no people no chance.

Was told they take pics of all traffic and registered owner will get the bill in the mail. Here and I think all East coast now takes the same transponder called EZ-Pass. Don't want one more thing to move car to car but may get one,

Tom

Response From Discretesignals

They were about 6" long and about as big around as a handle of a screwdriver.

Now Tom, don't get excited...

Response From Tom Greenleaf

Something told me you wouldn't leave that alone - Oh my,

Tom

Response From MarineGrunt


Yeah, I saw your picture on CNN.


Lol....I bet with your Vette you could've made the news MANY times!




They were about 6" long and about as big around as a handle of a screwdriver.



Now Tom, don't get excited...


Ha! I knew right when I type "6 inches" DS would join the thread. You're kind of like that "Little Johnny"!

Response From Discretesignals

I'm I really that predictable?


I'm getting ready to head off to Sam's Club. I am a big fish eater and they have these stuffed salmon fillets that are awesome. For around $10 you get six of them. Pop them in the oven for 20 mins and you think you died and went to Heaven.

$

Response From MarineGrunt

I'm I really that predictable?

Only if it can be turned into something perverted.


I hadn't tried salmon since I was a kid until last summer. As I kid I couldn't stand it and I was never a picky eater. I'd eat about anything (oh boy, here we go again) but just didn't care for it. Last summer when we were in FL we went to my aunt and uncle's for dinner. My uncle had just been on a fishing trip on Lake Michigan and pulled in a few hundred pounds of salmon. He smoked some filets up and my gosh were they great. It makes me wish I would've tried salmon again much sooner. Because of that dinner I plan on heading up to Lake Michigan and doing some fishing. I think the king salmon start hitting really good around October or November. I'd have to double check though. I'd love to have a freezer full of filets. Why don't you go throw some lobster traps in the water and we'll do some trading.

I think the wife and I are going to a movie either tomorrow or Monday. I'll have to swing into Sam's and pickup some of that stuffed salmon.

Response From Tom Greenleaf

Whole thread too funny MG. We (you) started with codes and look where we went. YOU DO NOT WANT LOBSTER FROM SOUTH OF CAPE COD MA - Trust me.

#1 in the whole world is Rockland, ME. Check this joint out, been there several times.

http://www.jessmarket.com/ (we don't allow links - too bad) they don't sell car parts.

OK - This place ships worldwide, live next day if you wish same day catch but they live a fair while just stuffed in seaweed.

If you want to blow some bucks this is the place. If you are really into it plain call them and ask for female lobsters! They have the red egg caviar (roe{sp?}) and duh the males don't - here we go again

Really mess with people's heads and ask for left handed ones and there are very few.

Definately get the 2lb ones...............

Tom

Response From MarineGrunt

I'll trade Tom for some lobster and DS for some Mahi Mahi then.


I got my crash sensor in the mail today so going to toss it on. I didn't get around to the cts this weekend but, today for the first time, the temp gauge is registering where it should. Kind of odd but I guess electrical components will do that at times. I'll probably pick up the cts this evening and install it tomorrow.

Hey HT....how does comparing the reading of the IAT and the ECT tell you it could be the cts? I'm just curious as to why so next time it happens I have a better understanding of it.

Response From Hammer Time

It doesn't tell you which one, only that one of them is wrong. The P0128 and new thermostat is what tell us it's the CTS

Response From MarineGrunt

Oh okay...I got ya. When you had me check the ECT and IAT on the scanner I didn't even really think about what I was checking or what the abbreviations even meant. I just knew that if HT said to check them I better do it! When it comes to diagnostics I have a looong way to go.

I replaced the driver's side crash sensor sense the passenger side had already been replaced. When I started it up no airbag light came on or no "service airbag" flashed across the dic so that took care of that problem.

This is probably a stupid question but I remember reading this somewhere. I have never heard of this any other time and wouldn't think it would be correct but figured I'd ask. Do certain thermostats have to self adjust? Since my temp gauge is now reading where it should and everything seems to be working it made me think of when I read that. I don't see how a mechanical thermostat could self adjust though. You know me though. I don't trust anything until I ask it here.

Response From Hammer Time

No, thermostats don't adjust. You may have burped some air out though.

The IAT and CTS are both temp sensors. One is intake air and one is coolant. If the truck has been sitting all night, they should both read the same temp.

Response From MarineGrunt

Thanks HT.

Hopefully it did just have some air in the system. I guess time will tell. If that's what it was I wonder if I had the same issue with the Envoy thermostat and the fix had nothing to do with the OEM thermostat I installed. Oh well, as of now everything is good to go on both. The only other fix I need to work on before winter is the Envoy won't go into 4 high. The automatic awd works though. The wife drives some north to south country roads in the winter and they can get pretty hairy with snow and wind so would like to get it fixed before November. I'm thinking it's the encoder motor but haven't even looked at or tested anything. That's for another thread though.

Thanks for all your help on the two codes. I'd say the issues pertaining to them are solved for now. Now it's time to figure out my central air unit. The compressor would click but not kick on and now the condenser fan won't come on either. I'm hoping it's just the start capacitor. My mom was in town and picked one up for me so I should know shortly. Like they say, if it's not one thing it's another. It's a little warm today but luckily we're having some great August temps in the mid 70's all this week.

Response From Hammer Time

Yep, I'm no expert on home AC but my guess is you are right about the capacitor.

Make sure it didn't burn out one of the dual 110 fuses for the outside unit too.

Response From MarineGrunt

Man you're good HT....I actually just checked power from outside box to unit. Power good at box. Checked inside a/c and no dice. Pulled the fuse and checked it and it's no good. Came on here and here you are telling me what's wrong without even being here. I need to move to south and be your neighbor. My wife would be a cookie making fool in order to pay back all of the work I'd have you doing!

Response From Discretesignals

Pulled the fuse and checked it and it's no good.

Hmmm... you found the effect...now what is the cause?

Fuse? How old is your house?

Response From Hammer Time

I believe this is going to be an outside switch and fuse box. Mine has 2 of those tube fuses for the 220.



Response From MarineGrunt

Yeah, it was the fuse in the a/c service disconnect box. The main breaker for the a/c didn't trip.

I installed the new capacitor and fuse and still no dice. The condenser fan is running now though but I think the only thing wrong was the blown fuse and believe the old capacitor was still good. The a/c unit has a hard start kit installed. When I turn the a/c you can hear the hard start relay?(little black box) click and it makes the yellow wire (power to compressor) move so I think it's attempting to start the compressor. I have a feeling it's locked up. and isn't worth replacing due to its age. I put a whole new furnace and ac in our previous house a couple of years ago. I sure wish I would've waited on it! I'm not sure if I mentioned it and it's too late and I'm too tired to look but when I hooked the gauges up to the a/c when it quit working the low side pegged out. Will it do this if the compressor isn't running or is it a sign that the compressor is toast?

Not sure if you guys know but I've heard sealed compressors aren't serviceable. Not that I'm going to but why couldn't someone cut it open, service it, and weld it back together? Then again, I do like trying to do things they say can't be done. I need to ohm the windings and see if I find anything. But, if it's a mechanical failure, that won't tell me a thing, right? I think another thing I need to do is check the voltage at the compressor when it attempts to kick it on.

There's really nothing else to replace. I would think that if the hard start kit was bad the compressor would at least make some kind of noise and still possibly kick on. With the hard start kit already installed that probably tells me the compressor was having some issues kicking on and it finally went. I can tell the unit is old and it definitely did its job well. I bet it's pushing 20+ years.

I need to get back to sleep. Whenever I'm trying to figure something out my mind races and I don't sleep for crap.

Response From Hammer Time

It's time to say good bye to it. The efficiency of the new ones will save you enough money to justify the replacement.

If that's 20 years old it probably around a 10 SEER and you you can get up to 17 SEER

I changed mine out about 8 years ago and went from a 10 SEER to a 13 SEER and dropped my electric bill by 25%. and mine wasn't really that high to start with.

Response From Tom Greenleaf Top Rated Answer

Have to agree. Have a 5 ton unit fairly new, 12 SEER up from who knows what and uses 1/2 the juice. It's total overkill for me personally and this year hasn't worked hard but this type (not my trade) removes moisture which pours out the side of the house like a hose running. Love that part anyway.

If you use air a lot the payback would be fast. How long will this newer junk last - all bets are they will fail earlier than older stuff as I can't believe super high efficient thin metals are going to hold up like the crap you could hit with a hammer and not hurt it?

Season coming to an end for us MG. Always (here) a good time price wise to get off season stuff,

Tom

Response From MarineGrunt

I'm 99% sure it's the compressor. I ohmed the windings and they didn't had up. I guess the readings from common to run + common to start are suppose to = run to start. My readings don't add up. I guess it means there's an open winding. At least it made it through most of the summer. With the a/c season being almost over I have some time to shop around.

Response From Tom Greenleaf

No doubt we have a similar climate to deal with so timing if this had to fail is good. Knowing you MG you'll find just the parts of the thing somewhere if you choose that vs an entire new set up.

Do the math for the payback of fix vs new for your needs. I do doubt new will last as long if only a motor simply not made as well as ancient stuff for many things home or vehicles.

On my third at my own place acquired @ just 8 years old the original burnt out compressor. Decided on whole new and it was more efficient big time but it too totally failed yet again. Current is now 1/3 more powerful and again twice the efficiency but the cost would have paid my entire electric bill for everything if it failed yet again so "Clara Peller" -- "Where's the Beef?" as she said.


IDK - I don't think the outdoor parts like Winters. Some cover thing, some don't and so far haven't seen any benefit in covering them up?

Tom

Response From MarineGrunt

CEL is back on and temp gauge is acting funky. Looks like I'll be replacing the CTS. I figured I wouldn't get lucky enough to have it be just some air in the system. It never seems to work that way for me.

Response From Discretesignals

Smack it with a hammer...lol

Response From Hammer Time

You rang?

Response From MarineGrunt

Smack it with a hammer...lol

Either a hammer or just use the ole' electrical tape trick.

I replaced the CTS a couple days ago and problem solved. Temp gauge is right where it should be.

Response From Hammer Time

My wife would be a cookie making fool in order to pay back all of the work I'd have you doing!

Keep her away from me!!

I have a sweet tooth and zero will power.

Response From Tom Greenleaf

MG - all. About parts by brand names:

Dorman at least once was a good name. What you don't know is if the item, whatever it is has just bought into the brand name or is still exactly what it was. In short the name and box gets sold out many times so hard to be brand loyal.

Enter stage left - then there's hacking things, essentially stealing the brand name. Doesn't seem to matter, automotive, household items or what. You really aren't going to know till it's in your hands and tested out.

This goes right down to a box of nails or household light bulbs. Dog-e-dog out there!

T

Impala overheating

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Question From hokihi82 on Impala overheating

Hey guys. New to the forum here and have an issue. I have a 2004 impala 3.8 with some serious overheating issues.

This past June, it overheated on me due to the plastic heater core elbow rupturing. During the repair of this part, I replaced the thermostat, the water pump, and the elbow. Everything has been working fine up until this week when the car would start to overheat while idling. Also the heater would start blowing cool air until the thermostat would open up and the gauge would go back down (I assume). After a couple days of this it began to get hot while driving as well.

Just this morning I replaced the thermostat which seemed to help for a little while, however after driving for about half an hour the gauge began to creep up again. While looking at the engine while hot I touched the elbow and it split open big time, spraying me in the face with some extremely hot antifreeze. I guess what I'm asking is this, does this sound like it had a small leak at the heater core elbow due to degradation or does it sound like maybe the water pump I bought crapped out on me? Doing the work doesn't scare me I'd just like some opinions or first hand experiences so I don't waste any more time or money than necessary. Thanks in advance.

Response From Sidom

I addition to leak checking the system you want to verify that the cooling fans are coming on..

Response From Hammer Time Top Rated Answer

You're first step is pressure testing the cooling system to find the leak. The intake problem that MG referred to is quite common mainly in the 3.1, 3.4, 4.3 and the small block V8s. The 3.8s aren't as common.

Response From hokihi82

Thanks for the reply guys. Not sure about the pressure yet, but I did replace the heater core intake tubing this morning. It actually didn't help at all even though it was broke inside the belt tensioner housing. I did notice that my radiator didn't want to take coolant so that may be where I nee to look next.

Response From MarineGrunt

We have a 2002 Chevy Venture with the 3.4L. About 8 months ago it acted almost exactly how you're describing. The heater would blow cold air until the thermostat opened up. It would then blow hot air and the temperature gauge would go back down. At first I figured it was the thermostat so replaced it. It didn't fix anything. After a few days it got hot while driving also.


The 3.1, 3.4 and 3.8 are notoriously known for bad lower intake gaskets. There is an improved design that replaces GM's originally faulty design. The mechanics here told me to look on the back driver's side of the engine with a mirror. I had to take the air duct off to see, but once I did, I could see some slight bubbling from the intake.

Don't go tearing into it until the mechanics on here give you some better advice but I'd put my money on the intake though.

I know I had the 3.4 but I might have some pictures from when I did mine. I'm sure they are somewhat similar. If you need me to post any pics just let me know.

2005 GMC Envoy 4.2 4x4 P0128

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Question From MarineGrunt on 2005 GMC Envoy 4.2 4x4 P0128

Check engine light came on the other day so I just got the code read. The code P0128 came up. It said something about the coolant temperature below what it should be. I replaced the thermostat back in May after we bought the Envoy. I know that doesn't mean anything. Everything seems to be working fine. Temperature gauge is where it normally is. Heater blows hot. If it wasn't for the check engine light you wouldn't think anything is wrong. I'm going to be out and about getting a Christmas tree so hoping to pick up any parts or whatever else is needed since my local parts store closes at 2:00 and closed in Sundays. Any ideas of what it could be and how to check for the problem?

Thanks!

Response From Hammer Time

That's usually just a bad thermostat, just not getting hot enough.

Response From MarineGrunt

I have to wait until Christmas morning for the high end scanner that HT is getting me. I've heard that he's even going to fly up and teach me how to use it.

What do you think of those cheap $100 scanners just so I could pull basic codes and clear them? I think I've even seen the very basic ones on sale for $50. Would one of those work just to read and clear codes? It would be nice to not have to run to the parts store every time I need a code read or cleared. Not that it happens very often, but if a $50-$100 one would work for that, why not.

Thanks guys. I'll get a new thermostat from the dealership on Monday and go from there.

Response From Hammer Time Top Rated Answer

MG, I have one of those pocket scanners that I use all the time for a quick read or code clear. Mine is a Mac that I paid about $200 for but it has data and stuff too. It's the hard stuff and the systems other than OBD2 generic that you need something better for. There are all kinds of lighting, restraint, suspension, ABS, instrument cluster, BCM and even alignment modules now that those things will be no help.

Response From Sidom

I have a cheap OTC as well.....The amount of data you can get with some of these cheap ones is pretty good. Some have a datastream and that is all you need some of the times...

I'm like you, I'll grab the OTC 1st, mainly because as soon as I plug it into the DLC, its on, my modis take a few minutes to boot & another couple of minutes for the VIN entry. So as long as it's something easy then the OTC is great. If I get an undefined code, need FF or the scope then I have to go the other route...

I honestly don't keep up on the cheap stuff. I'm only aware the additions is when a tech gets one. The last one I was surprise to see that it had OBD I abilities.....Hell I guess bi-direction controls is the next thing...........lmao

Response From MarineGrunt

I'll have to do some research on them I guess. I've kind of browsed online but have never really compared any. Unless you can recommend one that you think would be good enough for me. What model of Mac do you have HT? To be honest, right now, just one that reads and clears codes is all I really need. But, if I'm going to spend the money, it would be nice to have other options to tinker around with in the future. I don't really want to spend more than around $200-$300 or so but it seems there are plenty out there for less that will do more than I'll ever really need.

Hey DS. We're you being sarcastic about the thermostat? I put one in the Envoy back in May, and although it wasn't too bad, it wasn't as easy as my old cavalier work car I use to have! If I remember right I had to pull the alternator to get to it on the Envoy. Well, I'm not sure that I had to but did to make it easier to get to one bolt that was a pain.

Response From Hammer Time

I have this one, made by Launch but re-branded for Mac but I'm not saying this is the best way to go. It works for me. It boots up fast and I like the color screen. I think the Mac price is down to $169 now




http://www.launchtechusa.com/assets/products/CreaderVI.pdf

Response From MarineGrunt

I'm sure this is just coincidence but thought I would ask. The other day I ran to the store and the check engine light was still on from when it threw the P0128. After leaving the grocery store I went to the gas station to get gas, light still on. After pumping gas I started it up and the check engine light was no longer on. I know the cooling system is separate from the fuel system but didn't know if maybe the gas cap not being tight enough had anything to do with the code. With all of the sensors on cars nowadays I didn't know if it could affect something else. Probably a stupid idea but it just seemed odd how the check engine light went off when it did after being on for a week.

Since it's off, and I did replace the thermostat in May, do I need to mess with it or should I wait until it comes on again? The Envoy didn't show any signs of trouble even when the check engine light was on. I do need to drain some of the antifreeze and strengthen the potency as it only tested for 5 degrees and it gets colder than that here in the winter. It was down in the 20's the other day when it threw the code so didn't know if the potency and outside temperature could cause it to throw the code? Probably another stupid idea, but hey, I come here so you guys can smarten me up. Since I've been a member of this forum I've learned more about vehicles in the past year than I have in the past 10 years. I know you guys just love answering my stupid questions.

Response From Sidom

With a lot of failure that turn on the SES. The comp is still monitering that circuit. After it runs the same test and it passes so many times in a row the comp will turn off the light and story the code in history.

If I had to guess I would say that Tstat stuck open just enough to lower the coolant temp & set the code and is now operating properly......Unless you live in a very cold area and had a cold snap. In very cold areas a fully exposed radiator can get the coolant pretty cool before it goes back into the motor and might set that code..... That is why you see trucks with covers on their radiators just barely unzipped when it's real cold, it doesn't need the full area to run at proper temps...

Personally if I even suspected my Tstat was sticking......either way open or closed, I would be tempted to change it out.....Sticking stats can be bad news at the worst possible time....

Response From MarineGrunt

Thanks for the explanation Sidom. I live in Central IL and it did cool off for a few days this past week but we're back in the upper 40's now. I'll go ahead and change it out just to be safe. I planned on doing it this past Monday but then noticed the head gasket leak on the wife's old Venture so started that instead. I should finish the Venture up today and will then tackle the t-stat in the Envoy. After that I think the only thing I'll have to do is the rear main seal in the Sierra. Ha, it never ends! Oh well, with work being as slow as it is for me it gives me something to do plus, I enjoy it. I don't know though, if this Venture doesn't turn out I think I might "float test" all of my tools and be done with it all!

Response From Discretesignals

GM made them really easy to change. You'll like that one.

Response From Sidom

If you had a high end scanner you could check the freeze frame data and see when the failure happened & what the temp was. Also you could check the datastream and see what the coolant temp is....

If you don't have access to that, the easiest & cheapest route would be to install an OE tstat, clear the code and see what happens...

Venture head gasket replacement; questions

Showing 2 out of 16 Posts | Show 14 Hidden Posts
Question From Lemonpie on Venture head gasket replacement; questions

Hello, I am new to the forum and have read some good threads on the GM 3.4 liter intake gaskets and head gaskets. In particular the ones started by MarineGrunt in 2012. Like he, I also have a 2002 Chevy Venture with 141k miles. It was losing coolant, I used coolant dye, with UV light and could never find a coolant leak. I resolved then to replace the intake gaskets and before starting I used a Balkamp chemical detector with the blue dye over the radiator filler neck while idling. That indicated a head gasket failure as the blue liquid turned green/yellow in a few minutes.

I have the upper and lower intake manifolds off. I am cautious/slow, as I have only done head work on RWD cars in high school shop class in 1974. That was easy, this is harder!

Question #1. Regarding the passenger side torque strut. All that I can see indicates that I must remove the bolts that hold on the AC compressor to remove this strut. (Strut is a black painted, curved iron casting that goes from the compressor at its low side to the top of the front head at its high side). At its high side, it kind of "dowel-pins" into the top of the head, between 2 head bolts. Am I missing something? I really hate to drop the AC compressor if that isn't needed. (Why did GM do this?)

Question #2. The Haynes manual says I should pull the EGR connection and the oxy sensor from the rear exh manifold, prior to pulling he head. I hesitate to do both. (The Haynes manual also told me to pull the coil pack way too soon. You pull the coil pack AFTER pulling the rear valve cover as I see it).

Question #3. Should I try to pull the back head with the exhaust manifold attached or remove it with the manifold in place?

Last questions..Do you recommend leaving the Oxygen sensor original or replacing it simply due to its age,.....and should I grind the valves? (I will replace stem seals and check head for flatness).

I am in nearly over my head, at least I am in a semi heated garage with good lighting. The intake gaskets have looked pretty good actually.

Many many thanks in advance.

Response From Hammer Time

If i remember right, that A/C bracket wraps around one of the head bolts or the head itself and has to be removed.

Response From MarineGrunt

I don't know how you can remember everything about every car HT! That strut bracket does wrap over the head.

Here's a picture that shows how I left the exhaust in place. I know the Haynes manual says to do it a little different and alldatadiy says to remove the crossover pipe but I left that in place too. I think it might've been easier to split the exhaust pipe where it connects to the manifold and pull the rear (or left) head with the manifold still attached. My problem was the 3 bolts on the exhaust pipe weren't moving and I don't have a torch so couldn't cut them. It still wasn't too bad removing the manifold from the head. It was just that one nut that was a pain. I had a couple manifold studs break on me so if you're out and about you might wanna pick up a couple to have on hand.



I'll run out now and take a look at the bracket. Not sure if I'll be able to tell if the compressor goes over it or not. Wish my memory was as good as HT's!

I'm sure you plan on it but I'd replace the plugs and wires while you're at it. Now's the time to do them cause the rear are a pain otherwise.

Another thing that helps when install the lower intake is by getting 4 long pieces of all thread that fit in the bolt holes. You put them in the intake bolt holes so the intake slides right down in place. It will keep it from sliding around and messing up the rtv. I couldn't find the right size locally so bought some round stock and made my own all thread. I wanna say it was 12mm x 1.75? You might wanna measure a bolt first to be sure. When I did the intake gasket last year I think I used wooden dowels instead. You'll also need a 10mm crows foot in order to torque the side bolts on the intake. Make sure you tighten them down in the correct sequence. They came out with a new sequence and not sure if the Haynes manual has the tightening sequence. I can post it if you need it. Also make sure you get new head bolts. They have to be replaced because they're torque-to-yield bolts.

I have other pictures if you need to see anything how anything goes back together.

Response From MarineGrunt

The compressor has to be removed or at least the bolts have to be loosened. If you're facing the van the top right bolt on the compressor runs through a hole in the bottom of the bracket. Leave the lines attached. Loosen the bolts and just let the bolts and compressor lean against the sub frame. You only need the compressor to slide forward about an inch.

Response From Hammer Time

I'm pretty sure that compressor has to come all the way out as there are more bolts under it to get the bracket loose.

Response From Lemonpie

Thank you guys, very helpful. Especially the photo. I am trying to leave the rear exh manifold in place. The manifold heat shield screw seems stubborn, I'm determined not to break it but the shield might prevent penetrating fluid from working in to the threads. I will certainly replace plugs again (had new plugs and wires 20k ago when I had to replace the alternator).

Do you all recommend a new oxygen sensor with 141,000 miles? I do plan to keep car this for some years, I run my cars until beat. I don't know if they have a limited life (and I should buy new one) or if I should leave in the original one. I had pulled that out already but not the EGR tap.

Response From MarineGrunt

My front oxygen sensor went bad around 120K. I had to use my buddy's lift in order to replace it. I tried in my garage at first but couldn't get my arm up in there enough and at the right angle to get to it. It was a piece of cake on the lift. As to the life of one, HT will have to let you know on that. I want to say the oxygen sensor cost about $50.

I stripped a couple of the heat shield bolts in the process of removing them. I ended up having to use one of those stripped bolt sockets. One of the mechanics on here recommended I buy a set awhile back and I'm sure glad I did. I don't know if I would've gotten a couple off without them. Irwin makes the set I got. Auto part stores carry them and are about $20 for a set. You might be able to get some vice grips on the bolts too. I do remember them being tough to come out. If you're out and about you might want to pick up a few extra bolts. I think the are 6mm. I had to replace most of them because I stripped the heads trying to remove them. Keep soaking them with PB Blaster. That stuff works great. Maybe try and spray up under the top half of the shield if you can.

Once you get the heat shield off you'll be able to get to the manifold nuts. Like I mentioned before, 5 are easy and 1 is a pain. You just can get much of a turn on it and have to go by feel because you can see it. That's where that 13mm gear wrench will make a huge difference. I didn't have it when removing, but if I did, it wouldn't have been bad. It probably took me 15 minutes to get it off without the gear wrench but a minute to get it back on with the gear wrench. Once the nuts are off you might have to take a pry bar and gently pry back on the manifold to slide it off of the studs. You just barely have enough play for it to slide off. It wasn't bad though.

If you haven't done so in the past I'd replace the thermostat too. That thing is a pain to get to otherwise. When our van was overheating last year I replaced it before doing the intake. Wasn't much fun. You have to remove all kinds of stuff along with the heat shield too. I couldn't get to the bottom bolt with the heat shield in place. Best $8 you'll ever spend!

For that strut bracket I completely loosened all the bolts from the compressor but left them in the compressor and let the bolts, along with the compressor, lay against the sub frame. If facing the van the top right bolt of the compressor runs through a bolt hole in the very bottom of the bracket. There are two other bolts on that bracket. One up top that runs into the head and then another one a little over halfway down. You're able to get to those two bolts with the compressor in place. Like HT said, you have to pretty much remove the compressor in order for that bracket to slide up. The compressor slides forward and down a few inches which is enough to be able to remove the bracket.

I picked up one of these to clean all of the surfaces. They work great for aluminum surfaces. I used the white and yellow. I think the green is course, white is fine and yellow is medium.

Response From Lemonpie Top Rated Answer

Thank you for the helpful details MG! (I knew enough to replace the thermostat as it looks tough to replace from scratch). Thank you about the oxygen sensor, Hammertime. I have never had a issue with an oxy sensor and now I know- replace it.

Forum is a blessing.

Response From Hammer Time

0/2 sensors get clogged over time and become less sensitive to rich mixture. The can be a cause of some serious fuel mileage loss.

Response From Lemonpie

Do you think I should replace the one downstream of the catalytic converter too? I'm not working in that area.

Response From Hammer Time

No, that one has no effect on engine performance.

Response From MarineGrunt

I have always used a ratchet strap to rotate the engine forward. I like the idea about using a jack though. I'll have to try that next time. Hopefully there won't be a next time though.

Response From Sidom

These threads are huge so it may have already been mentioned but just in case you might have over looked it....

When working on the back bank, if you use a floor jack & block of wood & put it under the tranny pan & jack the engine, it will roll the engine forward making the back bank more accessable....

Response From Hammer Time


Do you all recommend a new oxygen sensor with 141,000 miles?

For sure.

Response From MarineGrunt

Question #1

I can't remember for the life of me if it is absolutely necessary to remove the compressor. It seems like I had the same problem you're having so I went ahead and unhooked it only to find out there was a hidden bolt around the middle. Seems like there was a 3rd bolt. It was kind of back in a "hole". It's easy removing the bolts from the compressor. A 15mm gear wrench comes in handy for one of the bolts. You don't have to disconnect the lines. Just loosen the bolts and leave them in place. The bolts, along with the compressor, will lay forward and lean against the sub frame. Only takes a couple minutes. I just can't remember if the strut bracket wraps along the side of the compressor or if one of the bolts from the compressor goes through a bottom hole in the bracket. It might even just kind of sandwich it together. I wanna say it curves along the side and you don't have to remove the compressor but I can't say for sure. I just remember I had the same issue. I'll try and take a look in the morning to see if it jars my memory. I do remember really having to wiggle that bracket to get it off. It was kind of seized on there a bit. Check in one of the "coves" for another bolt. I either took a mirror to it or I went by feel but I know it's there. Maybe try that before removing the compressor bolts.

Question #2

I didn't remove the oxygen sensor but I did pull the egr connection. You're talking about the metal "flex" pipe deal, correct? I think it's just a 3/4" wrench. Mine seemed to come off pretty easy. I think I took it off just to make more room. You could probably leave it attached and just wire it out of the way.

Question #3

For the back head I just removed the 6 nuts from the manifold studs. I didn't split the exhaust at all. I also didn't remove the crossover pipe like it said to do. The bottom middle nut was a pain. You can't get much of a turn on it. If I remember right I went and bought a 13mm gear wrench for reassembly because a 13 didn't come in my set. You can do it without but it takes some time. Once the 6 nuts were removed I had to pry the manifold back with a bar to get it off and on but the exhaust does move enough. If you have already split the exhaust pipe from the manifold you might as well just pull the rear head with the manifold still attached. The crossover pipe will come up with it unless you have it disconnected too. If you haven't disconnected any exhaust I'd just leave it all in place and disconnect the manifold from the head.

I'd highly recommend taking the heads to a machine shop to have the pressure tested and planed. I think it cost me about $150 or so for both heads to be tested and planed. How mad would you be if you got it all back together only to find out you had a hairline crack or a warped head! If it has never been done now might also be a good time to install a new timing chain and crankshaft seal. It will make it much easier since you already have the ps pump and alternator off. You know how tight it is working on the van so do it now while you have the room.

I'll be around all weekend so will try and check back in case you have any other questions. I'll get back to you about the compressor and bracket too. I sure wish I could remember! I know I wasn't that great of help but hopefully I answered a few of your questions.

You know. This is what I'm thinking happened with the bracket. The other strut had 3 bolts, right? I think I could only find 2 on the other so assumed that a bolt from the ac compressor ran through it. I think I removed the ac compressor and it still wouldn't come off. That's when I found the 3rd bolt. But, since I already had the compressor removed I can't be 100% sure that it has to come off. If you haven't removed the same amount of bolts that you did from the other side get a mirror or keep feeling for the hidden bolt.

Response From Lemonpie

Thank you, MarineGrunt, it should help me over the weekend.