Shop Jeep Exhaust Manifolds

1,000 isn't normal either. I would start with looking for a vacuum leak,

T

There are some repair products to patch them that I find don't last. Just search out the price of a new one and add an uncertain (to me) amount of time to replace it. If bolts and connection to pipe don't behave it can be labor intensive.

Not really sure that would cause the fairly wild swing in RPMs by itself. It may have burned something that counts or is confusing an o2 sensor - not sure?? An intake manifold or vacuum line leak to it. Intake manifold vacuum is a good measure of the load on the engine and other items are adjusted based on engine load which could cause your symptoms. Intake manifold leaks also don't usually impair the feel or operation when under part or full load/demand on the engine unless they are real bad,

T

same problems but it does it right off,im about to pay a bum to drive into a local jeep dealers show room ,e
i have replaced all three sensors on the throtle intake,starter,batery,pcm,relays,fuses,cut the cat out put new one in,new o2 sensors, no wires crosed or out of place,replaced cap rotar,wires,plugs,

on subject off subject had to pull two relays nothing on at all but massive drain on battery,second i cut the cat out because of massive carbon build up, the night i cut it out replaced with welded pipe an o2 sensors it got 18 to 22 mpg home 30mile drive, next day went back to running like crap with new added problem you can be drive fine bad mpg and it sputers if you mash the gas does nothing but about stals out let of the gas goes back to okay idle then it goes back to almost stalling to very loud back fireing, with thick black carbon smoke cloud.

This is a 2 year old thread. If you have a question, please start a new thread.

Also, would a bad chain cause me to have poor gas mileage?

Thanks

A loose timing chain could cause some of your problems & would definitely affect fuel economy. With your setup there is 2 ways to check it. One would be to put a breaker bar on the crank & move the crank back & forth while looking at the rotor in the dist, noting how long it takes to go from one direction to the other. There is no real spec for movement, it come down to experience. The 2nd which is a little more accurate is to hook up a lab scope to the cam & crank sensors & check the sync of the patterns while running, noting for movement while reving the engine. Any thing more than 10º out indicates something is going on.

From what you've said I would probably start off with making sure there in no exhaust leaks. You should never be getting exhaust gases into the cabin. Those have had problems with their exhaust manifolds & an exhaust leak would affect your gas mileage, it would lean out the exhaust gases making the comp compensate by adding more fuel. a look at the fuel trims would help confirm this.

As far as the low idle, I would be looking at the IAC pretty close. Those are a dual coil IAC and in the past I've had problems with one coil going bad & not setting a code, also since it is electrical, the failure was only happen when hot & under load.........

A very high percentage of jeeps were indeed fixed with the pcm screws , Go back and try backing out those screws a couple of turns .If no change ,go to a salvage yard and get a pcm harness and swap it out. One other thing ,look down at front of eng in the opening in front of #1 exhaust tube and see if the harness is stuck to it.

The contents of your response is an entirely new concept to me as I have never heard of this or had this mentioned to me by any of the mechanics I've been to. That being said, could you be gracious enough to tell me what that is, where it's located, and how I would go about checking to see if what you have recommended is bad?

I have read A LOT of different forums relating to my problem and all of them indicate that it could be a bad EGR, IAC, Map Sensor, or Throttle Position Sensor. I am just wondering if you are dismissing any of those as the answer to my problem.

Sorry if I sound like I'm prying, it's just that I have been spending a lot of time and money on trying to fix this problem and I'm fed up. I'm really placing a lot of hope in this particular forum to end my many months of anger and frustration.

Thanks again!

I think this engine uses a timing chain. They can be erratic and fool techs.


Check for lash in that chain. 160K is enough even for real chains vs known maint for the rubber ones,

T

Forgot to give the Specs.

- 1991
- Jeep Cherokee Laredo 4WD
- inline six, 4.0 liter
- 273,353 Mile on it
- Has had only one other owner, and has never left the state of NC.

I'll venture a guess here....(all I can do without hearing it)

Brakes....Sounds like a faulty brake vacuum booster or maybe the vacuum hose to it came off or is leaking

Axle noise?...sounds like it could be an axle bearing

Engine....worn out..basically...sounds like lifter noise.....
Try adding an additive to the oil,change the oil and in place of a quart add a quart of "Risolone"...may help,may not.
Does have high mileage on this

Thats my thoughts

Thanks, Yea I had called a friend and he had mentioned something about the Booster, Sounds expensive but ill check it out if its leaking or not...

and im not sure if its the axle or not but it make some pretty bad humming toward the back of my car.

And for the engine ill give that a try, Is that the name of the product, or the manufacture?

Thanks for your reply!!!

Name of the product..

I use it a lot..have had some good results....don't know if it will help in this case or not....can't hurt...
Worth a try...costs more than a quart of oil tho...like $4.00 or more..

That doesnt sound that bad, 4.00 is nothing compared to an engine fix.. But thanks for your Suggestions and tips!!!

Well I Got the Brakes Fixed, it was exactely what you had Said it was the Brake Booster, And Im going to have the back end looked at, other than that i changed my oil and put the Oil additive into the engine in place of the exrta quart, and am hearing some improvements...Thanks A Bunch!!!!!

Who Are u??? Can Someone find out who this person is cuz I haven't gotten my car looked at yet. But i Have Gotten My oil changed and added the Risoline Additive.. Can This Guest Give Me An Explaination for him/her butting into my thread like they were me????

Hello JeepGoingFast. Whoever posted as Guest posted their responses from the same computer you use. So who is the Guest??????

Sorry Bout that, My Friend wrote that he was being a prick, I thought someone else wrote it... anyway if you could just delete those Messages That would be cool.. Thanks

Hi Imscagain, did you ever find out what was causing the candle wax smell in your Jeep? I'm having exactly the same issues on a 03 Liberty and it is driving me nuts

Thanks,

Andres

This thread is 4 years old. Please start a new thread of your own instead of posting to other peoples old threads.

Any Ideas? >>
I can say, with almost certainty, that a dead toad does not smell like burnt wax. Hot brakes have a distinct pungent odor.
>>like when you blow out a candle<< That could be a description of an electrical over-heat? I would agree to keep a close eye/nose on the alternator. Wish I could smell it, myself. An overcharging battery will give you a 'sulpher/rotten egg' smell. Good luck.

May want to check for the infamous plastic bag stuck to the bottom of the catalytic converter. lol Sounds funny but I see this more times than one can imagine.

Steve

Man am I glad you guy’s had a couple of ideas of what this smell might be. I read the question earlier and didn’t know what to think?
Other then a calliper hanging up after the vehicle was driven for a bit; around the block isn’t enough at times to heat up the brake; if there’s a sticky calliper?????

Dan.

Thanks guys! - no brake issues - had those rechecked again after the smell started. (new ceramic brakes started all this)- nothing stuck under it either. It is definately not an electrical smell. I've had enough experience with that! lol. I did have someone mention that my remanufactured alternator could smell like that if it is going bad and said to put a long screwdrive on the housing and listen for a grinding metal sound. I guess I will try that next.

It's been too cold for the engine to heat up alot so I haven't had the pleasure of smelling it for a few days. When it is hotter out (I am in Florida) it seems to happen sooner and more often. Sometimes within a block of home - sometimes not until I get 30 miles down the road - sometimes inbetween.

When I thought I was going crazy - I had 3 other people smell it and they all agree - it smells exactly like when you blow out a candle. That burnt wax smell. Weird indeed