Shop Infiniti Head Gaskets

You need to fill the engine and radiator full with any tricks you can before you fill the recovery tank or first warm up the remaining air lock will barf out coolant and all to the tank. It could have a head gasket problem but get the air out first and then we can discuss that,

T

How do I get the so- called air lock out? Let me know pleeease..

What prompted changing the thermostat to begin with?

The thermostat when cold is a stopper for coolant flow to radiator so air can get trapped any time coolant is lowered or lost for any reason. Vehicles with the pressure cap at the recovery tank which I think this one does are harder to know that the system is truly full when refilling. It's a real problem in some cases to get all that air out.

Just how did you refill the system? Some vehicles you need to fill thru a hose when removed or open an air bleed on the engine probably near the thermostat.

I'm just guessing that what happened is the air heated up in the engine and it will expand faster than coolant and push whatever coolant in its way to the recovery tank first appearing to be overfilled. The idea is to push air to that tank and return only coolant when the engine cools and coolant contracts - self purging but wont' just do it in one shot.

Bet if you go back and look now the recovery tank is empty or low again if cooled off now. Many cycles of that would purge out the air in time but you shouldn't wait or let it overheat which it could just letting it do it on it's own which it may not unless you have it mostly filled to begin with.

Just where are you at with this now?

T

I found the bleeder .Looks like a brake bleeder on the thermostat housing. Do I drain some coolant out then open the bleeder while filling? I hate to be a pain.But a quick walk thru whould help.I'M lost on what do I do 1st ect. Thanks.

Ok: Bear with me and I'll get back to this with a more detailed procedure which may take some time for me to think out. For right now - if that is just like a brake bleeder it probably won't bleed air until removed and cleaned - if so have a plug for the hole ready. The basic idea is that air rises over liquid and can't pass thru the thermostat when it's closed which traps air. Back later,

T

Thanks Tom ;]] Let me know

Ok: Let me give this a shot at explaining. I spent the day thinking of how I could write something about this that could easily explain this problem and the solutions so it could be referred to for many as this is a common problem. There are some tricks for exact makes and models but basically the same thing.

* Think of the cooling system as two areas - engine side and radiator side. About always a thermostat is at the highest point between them and shuts when cold and gradually opens when it approaches the set temp then fully open to circulate the coolant to radiator and return the cooled, coolant to the engine.

* The T-stat is capable of being somewhat air tight when cold/closed. When coolant is drained or lowered on purpose or from a leak it will lower the level in the engine side and the radiator side. When filled again at the radiator side the coolant fills what it can but can't push the air on top of remaining coolant in engine back thru the T-stat so it's locked in there till the thermostat opens and the air (naturally at the top) goes out to radiator, liquid coolant should return thru the lower radiator hose to the engine and you would notice the drop in coolant level at the radiator - a good time to fill again BUT.......... vehicles without a radiator cap on the radiator itself just don't manage to get that air out to where you would fill it at the pressure recovery tank so you have to be assertive with them.

!! I'm winging it here so bear with me. The idea is getting the air out of the locked engine side to where you can replace it with coolant of the side you are supposed to be able to add directly to, to replace air with coolant. By itelf it would purge air out to recovery and return just liquid... note the tank has a little hose at the bottom that allows coolant flow to and from the radiator. Just that smaller hose is slow to accomplish this without intervention when system has been drained.

It's hard with these to just let the engine warm up enough to have the T-stat open and stay there long enough to on the difficult ones you would let air out of the engine side before the thermostat with a bleeder if equipped or taking a hose off on that side as high up as possible and fill it there and re-attach. When you have most air out just normal driving around will get any remaining insignificant air out to that recovery tank a little at a time over the cycles of warm and cold - expansion/contraction of the coolant.

Warning: When dealing with a cooling system don't open up when under pressure. You can feel that there is pressure fairly easily at an upper radiator hose - use a rag and don't get burned. Water/coolant is a liquid at temps below 212F (rough ave) and a vapor above that with no pressure on it. Water/coolant will remain a liquid at about 3 extra degrees per lb of pressure. If that pressure is released it can and will flash to a vapor and can cause serious injury! Apply common sense folks.

Now a snag with assorted ways the heater operates. When filling and testing the heater should be on full temp request and low fan. Feel for the heat. That proves that liquid coolant is there as even hot air going thru a heater core won't exhange much heat. Some heaters have a constant flow of coolant and adjust the temp desired by controlling flow of the coolant itself or use a diverter door to blend heated and ambient air temp to deliver disired air temp to cabin. This will vary in assorted vehicles.
NOTE: Some vehicles use the heater/core - coolant flow as part of the by-pass system which allows the water pump to maintain even temps inside the engine's coolant. This is necessary so that the thermostat gets the real overall engine temp or it would fluctuate and cause problems of its own.

Note again: This is with the components of the cooling system all in good shape and able to work properly. Debris in cooling system, leaks, head gasket problems, or defects of assorted kinds can and will complicate the success of purging air out of a cooling system.


Ask away as needed. I'll try or others please jump in and edit this as needed. This is a common problem. Techs and DIYers alike have to deal with this frequently,

Hope that helped for now..........

Tom Greenleaf, 2-3-2008

Wow..Thanks sooo much for the time you spent helping me out. I went out yesterday and tried the bleed off thing. I made sure the system was full. Well , I opened the cap which is NOT on the rad and topped it off. Started the car and opened the bleeder. It spit air out and I did it till the coolant got to hot and closed the bleeder. I repeated this again after a cool down. I let the car idle for 10 mins after.

Then I revved it up to 2-3 grand for a bit.. I watched the overflow tank and it never filled up !!!

I drove it for a bit and had no problem. I need to take it out for a longer drive today.

I am crossing my fingers here, But it seemed to work . I will let you know more after a longer haul

I went and smelled the exhaust and could not smell anti freze in it..Hoping this is NOT a head gasket problem. Again many thanks for your time.

I will let you know more today. Randy in Fayetteville Arkansas..Go Hogs !!!!!!!!!!!!!!!!!!!!!!!!

Randy - That was my kitty's work. I left the 'puter on and she was sick of waiting

I don't think you have a head gasket problem. Just keep a sharp eye on the temp gauge and leave the heater on if you can stand it even if not needed for a while. As mentioned the heater will quit blowing warm air when only air is passing thru it. That can be just air or bubbles from the coolant boiling and actually is a faster warning than the gauge sometimes. If you do overheat you are back to square one with this. It should begin or already be very stable and you can just archive this as not quite as simple as it looks for just swapping out a thermostat!

T and Kitty!

Mucho thanks to Kitty then ;]] It is very cool of you to take your time to help others. The world needs more like yourself in it.

I will give you a update when the wife takes it to work Monday. Thanks again..Randy in Arkansas

I spoke to soon .. The wife got home today after a 5 min drive and the radiator hoses were not hot yet. But the coolant was filling up the overflow tank??

There is pressure somewhere.. I feel it IS a head gasket..Damn!! I bleed the system 3 times..This sucks.

And the coolant in the overflow tank was NOT hot?????

Dangit!!!! It's possible. Know that anytime air is heated out of sight it will expand tons more than a liquid which pushes the coolant out to that tank. If that air (I guess I should say 'gas'/'vapor' ) is in fact from combustion gasses or exhaust gasses then it behaves like plain air in the system. It keeps coming so you can't just purge it out if in fact that is what is happening.

Head gaskets don't always leak coolant into combustion or oil but can leak about any thing they seal from one to another.

Ever heard the phrase "Blow a Gasket" as an expression of exasperation? Appropriate isn't it? Get a good diag before making the decision to replace the head gasket and all that can go with that. We are still here and will try as best we can to minimize wasted money and effort on your part,

T

Thanks Tom.. I had one guy say maybe the impellars are shot on the water pump. Could the radiator be plugged up a bit? When I bled the system it never did run out a solid stream, Like I could not stop the air purge. But to push the coolant to the tank,I touched the fluid and it was not hot has me bafooned. Randy

Excellent work Mr. Greenleaf. This is for Kitty (and you).

The "white" smoke may have an odor and also might go away after start up and stay gone.


Would think you'd be noticing loss of coolant if it's done that a while. The rest is I think this engine is all confused as it's relying on normal compression and normal intake manifold vacuum for lots of operating functions even in 1993. Try for codes for an area of a problem noted but the white smoke is the killer.


If you've disconnected the battery or it's gone totally dead anytime recently I'm near sure this car will forget how to hold a normal idle having lost memory that over time and use covers the changes of slowly getting dirty in throttle body and other things like plain load on engine from accessories or just sitting in drive vs a neutral.


Pull plugs at least and look for maybe one only or more that is too clean or worse plain wet with coolant. Pressure test could find it and could (if bad enough) fill a cylinder with coolant and lock engine?


There's a list of maybe things but not a whole long list on why it could blow that white smoke. Check oil for contamination too.


Fuel injectors can if before you found a bad one have been flooding the thing washing lube of that cylinder badly and you'd find it way off now.


Just check easy stuff as I do think you've got some bucks ahead that might be more than you would want to spend on this exact car. It's worth bucks (for metals if nothing else) as scrap priced local to you.


Miles alone don't matter way too much for a very well cared for car/engine but time counts and stupid stuff like even the seats lose it, knobs and handles only take so much and get annoying - your car, your call but find out what you can before tossing bucks at it,


T

Thank you very much Tom for taking your time and explain it to me. you are right I dont want to start spending on something that might or might not work.
I will do the check list you said. the one good thing this car had when I baught it was the full repair service manual and that is what I had been using to fix stuff on it .
The book probably worth more than the car itself now :)

It's not over yet just need to find out where you stand. Great that you have manuals and no doubt worth something. Sorry if I'm stuck right at the "white smoke" but it's the most important thing to know why. You did say it smelled like fuel which would be dark and sooty unburned fuel. If extreme enough probably soil a cloth for a close look.


It doesn't take much coolant to make a cloud of smoke nor oil. It may be confused with the standard color of what you see and going away once finally running can happen.


OK - Consuming some oil may not mean too much by some miles but shouldn't really be seen and always note how long or miles it takes for oil consumption. Coolant really shouldn't use any but rather just expand with heat and contract with cooling off at close to marked levels of tank AND remain always full at radiator.


Spark plugs are very telling of what is going on inside cylinders. Even if older you look for them to be the same unless clearly ONE cylinder shows lots different from others.


Try to do as much diagnosing as possible while it's intact and running as that ends if you have things all apart.


Stinks but could take a while. If running poorly you risk the cat converter(s) too. No problems from me keeping and using old vehicles some had some much higher miles than this but a history of most since new on many of my own on most which helps some.


Add any recent work that might be a cause of something now that's overlooked too,


Tom