1995 Pontiac Grand Prix se PLZ HELP

[t-roc]

Hello i have a 1995 Pontiac Grand Prix se with the 3100 motor in it.
when i purchased it i ended up 2 weeks later having to put all new gaskets in it, Head gasket, intake gasket the whole works, new thermostat
everything. Well car was perfectly fine no problems at all heated well ran well like a top. Went from NY to Florida no problems at all ..
Now we get back and now the temp guage wants to play games.
Rise al lthe way up slowly come down rise up again over an over
throws heat when the guage is down cold air when guage is up
we have replaced the thermostat again twice
we arent loosing coolant the collant is staying full and we have even tried to bleed out the air in it many times
plz if anyone can help plz do the car is in too good of shape and only has 75,000 miles
Thanks GM USER IN NEED

[BNaylor]

Welcome to AF.

The engine temperature gauge at the IP Cluster gets its signal from the ECT - Engine Coolant Temperature sensor via the ECM module. On a 3100 it is located by the thermostat on the lower intake manifold. I would check the resistance/calibration of the sensor to make sure it is good and then work up to a possible IP or gauge problem. Also, check the ECT electrical connector for corrosion. Clean and ensure it is properly connected.

As a simple quick test disconnect the electrical connector to the ECT and then see what the gauge does. The gauge should read to the far left. Also, when you do this test the cooling fans may turn on in hi-speed mode but that is OK. If the gauge still reads with ECT disconnected then the problem is towards the ECM module, wiring, or the IP Cluster.

[t-roc]

but would that casue hot ait to blow when guage is down and cold air when guage is up?

[BNaylor]

Originally Posted by t-roc

but would that casue hot ait to blow when guage is down and cold air when guage is up?

Maybe I missed something. Technically no. When the engine is properly warmed up what do the heater core input and output lines feel like regardless of what the temp gauge is reading?

[t-roc]

well i unpluged the sensor i thought u were talking about but the car wouldnt stay running with it unpluged so must not be the right one. everyone is telling me (mechanic wise) that it still has a huge air bubble in it .. well what is the corect way of using the air bleeder system. I have two one on passenger side of car like a 7mm and a straight head screwdriver on the drivers side of car

plz help im pulling my hair out over this casue everything has been changed new
plus i mention sensor to other people and they are telling me that wont stop from getting heat
again thanks in advance for soemones help

[SUERED]

A ten year old car with 75,000----both of those facts begin to lead to plugged radiator possibilities. The 95 GP my sister in law has started out with the orange coolant--which if not cared for right--can really do a sludge number on your cooling system including the radiator. A GM dealer flushed ours and put in the green stuff when we bought this GP in 2002. 1995 was one of the first years I believe they used that orange stuff and there were problems if I heard right. I have replaced the radiators on our other older Ford cars --both are 80s vehicles. Whenever I see comments about thermostats on such cases as this, my mind driffs into the radiator theory. Have your radiator checked. When you get to 10 years of age, the condition of the cooling system then begins to depend on how well it was cared for in the prior years Since you are not the first owner, anything is possible from the standpoint of previous owners. If there is doubt on this radiator- I'd replace the radiator rather than put the engine at risk. The problem here I believe with replacement, is that a GP radiator is not cheap. My Fords were. BUT a ruined engine puts a 95 vintage out of business --value wise. Choose wisely especially after you have made an effort with other engine repairs--good luck!!

[richtazz]

Your t-stat sits sideways under the throttle body and is a bummer to get to. I always drill a 1/8" diameter hole in the t-stat flange to help air escape while filling the system and the t-stat is closed. Install the t-stat with the hole in the 12 o'clock position and follow the fill proceedure I mentioned in the thread below.

http://www.automotiveforums.com/vbul...=coolant+bleed

If this doesn't fix the issue, you probably have a clogged radiator.

[t-roc]

thank u both for ur help and info .. its a tad cold here to be working on it now so next warm day i will have to try the thermo stat idea first and if that donthelp then its off to Pick-a-Part junk yard for radiator
i will post a message when i test it all
thansk again

[SUERED]

Oh Boy,

I wouldn't want to disappoint you by having you tackling a radiator without being sure about it being the problem. Junk yards are not the best place to get a radiator. I would think you are spinning a roulette wheel on something like that. A junker might be in worse shape than yours. First thing I would do in regard to the radiator --is buy a spray bottle of coil cleaner. It is sold for cleaning AC coils. You spray it on the exterior of the AC and radiator coils. Chances are that the exterior of your radiator and the AC condenser (which is in front of the radiator) are dirty and were never cleaned? If these are air restricted, it doesnt matter how good the interior flow of coolant is-- The radiator will still not be effective. If the $10 you spend to clean up the exterior doesnt help, then it is time to consider having the radiator checked for internal blockage.
Again, the radiator is behind the AC condenser --so it is not always easy to clean unless you have the mind to remove the radiator from the car. I once blew the cooling fins right out from the radiator coolant rails by using a power washer. Be careful as the fins are bound to be fragile with an older car. There are also cleaners available for internal cleaning of a radiator. You could, as I said, remove the radiator and take it to a radiator shop for repair. They'll tell you what the deal is. If it can be cleaned, they use chemicals.

[RT87]

The problem is probably not your thermostat. When the lower intake manifold gasket starts to go, you will get higher than usual temperature readings.

I know that you had the parts replaced just a short time ago, but there is not a great deal of torque on the lower intake manifold gasket, especially at the ends of the manifold and intake gaskets will fail if not installed correctly. If you are still within warranty on the previous job, it is worth going back to get the job done right. If you are not, go somewhere else.

[richtazz]

Actually RT87, there is very little torque on the intake bolts on these cars. That is where the original problem stems from. Failure to use threadlock on the bolts during re-assembly will cause them to loosen over time and start leaking again. The intake bolt torque on a 3100 is only around 18 ft/lbs on the outer short 4, and 128 in/lbs on the 4 inner long ones using the new design metal/rubber gaskets.

[Shoughun]

AC condenser may tend to be overlooked at all times but if this is damage, you sure will seek for its repair since you wont be able to stand the heat your vehicle can give you plus the confided feeling you get from it. But you sure know that this will not function very well without the help of its subparts which includes the GM AC Condenser.


Primarily, the GM AC Condenser is a necessary subpart of the system responsible in dispersing heat within your interior. Without this, the air conditioning system will not be complete and will not function properly therefore giving you a very uncomfortable drive along the way. Furthermore, The GM AC condenser is comparable to the work of the radiator since the two dispels heat.



But because of the fact that this component is located at the bottom of the AC system, things will most likely boil down to its destruction because its location is susceptible to dirt. With this, it is vital that you check on it from time to time. Also, if it needs replacement, address the problem right ahead. Seek only for the GM AC Condenser that matches with your vehicle. During installation, you can ask the help of a mechanic to do the task for you.

[t-roc]

ok changed the radiator casue another mechanic told me same thing so i bought a new one for 160 bucks .. wel lstill does same thing .. thought even tho its a new water pump we bought a new one of them too .. we arent loosing any coolant and its not mixing in the oil and its not smoking anything so it cant be the new head gasket or intake gaskets

got us stumped by the hair
*chuckles*

p.s even tried another brand new thermostat ..
its a matter of gettign it bled i belive jus tcant get it bled fully/right
i printed out the one guys how to bleed these systems page so im off to try that
ill write back when i make out and let ya know
thanks for all the replys

[t-roc]

haha well now im motor hunting everything went up in smoke i think the intake gasket blew again and i said screw it and kept driving i had to get home .. well now the car has no power unless u can keep it at 4000 rpm
if u guys know of any online websites that sell cheap used motors plz post so i can check out

[SlugHog]

THough I know this i a dead opic, thought I would add this n case someone doing a search like myself wants something new to try.

First off, my wife drives a 95 Grand Am, 3.1 litre engine. Every now and then it would over heat, well the gauge would rise. She would pull over, put it in Neutral, give the throttle a shot adn low and behold, temp would fall.

I went through the hell of replacing noticing that the one in the car would stick. After doing that, could not get the air out of the system as one hose would be hot, the other, ice cold.

Now the real reason for my reply. Instead of using the bleeder valve to patiently wait for the air to leave my system, I removed it. I did things in this order.

Loosened the bleeder, the whole unit, as in bleeder assembly
Started the car
Removed the bleeder assembly
Then removed the cap on the reservoir.
Within seconds I could feel a strong rush of air and within a few more, coolant starting to rush out.
Quickly replaced the bleeder assembly and the car has run great since, well as far as cooling system goes anyway.

Please make sure you have a catch tray under the vehicle when doing this as it is a bit messy and not environmentally friendly if you don't.

SlugHog