95 Grand Am overheating

I'll try to be as detailed with this as possible, since there seems to be many problems tied to overheating.

The thermostat and waterpump are less than a year old. the stat should kick in at 195 degrees, or by my dash guage, at about 220 degrees. My car seems to stay above 220, and tops at a bit above 250 (where the red starts). It may go higher, i'm not going to find out. The coolant seems to hold pressure, you can hear the release when taking off the cap. The cap still has it's gasket, so i'm assuming pressure is not a problem.

i've been told running the heater helps cool the engine, but it actually runs hotter with it on, than with it off. Also, with the AC on, the fan does not seem to turn on (unless it's delayed several minutes). The fan does turn on, but seems to turn on randomly from what i can tell (it does not turn on by itself when the guage reads above 220).

What else... ah, no milky colors in my oil.

My first assumption is the thermostat's shot. However the temperature will drop, but only when i am accelerating (typically during a gear shift, 2nd to 3rd). The longer i accelerate, the more it cools. Usually it still likes to stay above 220. It heats up fairly quickly too, I'd have to do this every 4-5 minutes to keep the guage out of the red (red range is 250-280, btw). It heats up worst when idling, and badly when cruising as well. I do have a coolant leak, and you can smell it buring, but only when it's sitting idling for a while, and never seemed very serious.

My car provides me with my income, so any help would be greatly appreciated.

hey wuz up my name is matt and i have a 95 grand am and i had the same problem the way i fix the problem is i removed the theromsat and ran the car without it and my overheating went away.

That works, but not the best idea in the world to run your car without a thermostat.

Even though the thermostat is only 1 year old it could be bad. I would replace it and see what happens. Secondly, I would check the cooling fans it seems that they may be part of the problem. If you turn on the AC the fans should come on right away. Also buy a new radiator cap. The one you have may not be building pressure. You stated that the faster you go on the freeway the cooler it runs. This is due to more air flowing through the radiator and discipating more heat. One other suggestion is to flush the radiator, you may have some clogged tubes that are not allowing coolant to properly flow causing a restriction.

what size engine is in the car. i had a 2.3 and i had all of those problems. i changed the thermostat and the water pump. i flushed the coolant. i had the pressure tested on the head and it was fine but about two months later the head cracked wide open. i didn't have and milky stuff in my oil and no oil in my antifreeze because the gasket was fine. if i were you i'd sell it and be done with it because you'll probably find out in the long run that it wasn't worth the time or money you put into it

Simple first things to check are make sure the cooling fins on the rad are not clogged with debris like leaves, dirt and bug guts. Let the car sit running and check and see if the cooling fan kicks in at all. If your car is your income you probably have a lot of miles on it? It probably wouldn't hurt to have the coolant flushed. And definately fix that leak. Chances are if you are checking the coolant level when the engine is hot, really hot, it will look like you have the right amount of coolant when you actually don't. Check it in the morning or when the car hasn't been run for a significant amount of time (5+ hours so the engine is good and cold). The reason for this is because the hotter the coolant is the greater it expands which would make it appear to be full, once it cools down you may find your resevoir to be empty.


Marc

The pressure's been checked, a new thermostat put it, back-flushed the system, and purged the system of air. The bad news, the problem is not fixed. It turns out that half my radiator gets hot, the other half stays cold. In other words, my radiator is probably clogged and overheating my car. That's at least my best guess right now.

If you are still stumped after checking the rad, have a look at your intake manifold. I had a Beretta and a Corsica that started running very hot after about five years. Had everyone stumped. My mechanic was fixing an oil leak on the back rocker of the Corsica and had to pull the intake manifold to do so. Sealed everything up and the car was running cool again. He figured the intake may have had a small leak and was sucking in hot air from the engine as it ran. I figured my Beretta may have had a similar problem so while it was running I sprayed WD40 around the intake and the engine began to stumble as it was sucking the wd40 in. Confirmed my intake was leaking on the Beretta as well and also corrected my heat problem.

Sounds like my issue as well. I even went into the fan control circuitry and found out the fan is not supposed to kick on until the water temp is at 220* or 240*, which of course, I never let the car get to. I replaced the radiator because it had a leak anyway and it did nothing to the temp.

I definitely believe the intake manifold being the culprit. I haven't been at home in a while so I haven't had a chance to look into it. I know it's a common problem on my 96 GMC sierra. Should've known it would also be common on a Pontiac (GM).

The problem continues. I now have a new thermostat, flushed system, new fluid, and a new radiator, but it still runs well above 220 degrees. I know the fan works properly now. I even tried the wd-40 around the gasket of the intake manifold, or what i could get to. I let it run for a few minutes, but nothing changed... Any other suggestions?

The problem continues. I now have a new thermostat, flushed system, new fluid, and a new radiator, but it still runs well above 220 degrees. I know the fan works properly now. I even tried the wd-40 around the gasket of the intake manifold, or what i could get to. I let it run for a few minutes, but nothing changed... Any other suggestions?


After everything you have looked at, how is the heater core? I'm going to suspect the heater core is restricted. Even with a flush it may not clear it out. I ran into a situation this past May where a flush actually clogged the heater core, resulting in having to backflush the core with pressure.

It actually was backflushed. Currently I'm having the water pump replaced. I replaced it a year ago, where the pump destroyed most of it's fan blades. The idea is that it basically did the same thing again, which explains why the only time I can get the temperature to drop is during a long acceleration. The high RPMs are needed to push the fluid with what few blades are left on the pump. *crossing fingers*

shmig, any luck with the new water pump? Did you look at the old one to see if it was damaged?

Has your 1995 Grand AM had the FREE Ignition Relay added during a recall many years ago? I just bought mine used 2 months ago, and it did not have one, and it caused all sorts of problems in my car.
From what I understand, these cars ended up with too much power running it's course through an insufficent wireing system... especially as the ignition is concerned. But at any rate... without one, it can cause wires to overheat, become losely connected, or come apart; and or catch fire. Remember. Where talking sensors and wires for all these parts in your motor, that can feed mishap info to the comp and performance and opperation rules, and so on.
A certified GM delear/mechanic will solve this problem for free. They added one to mine yesterday, fixed my wires... and now my car runs great. Once they add the relay, you have nothing to worry about.

Just say you heard about the recall....... IT's FREE FREE FREE.

Sorry for the lack of update. Basically, I had it purged again after the radiator, with 3/4 gallon coolant added. It been running alot better, so I haven't replaced the water pump. It still runs what seems to me unusually hot when the heater is on. I haven't seen it reach the red yet, but it's getting very close. I'll have to look into the relay too, just in case.

My car is doing the same thing man...I mean the exact same thing. The only timemy fan will come is when i select defrost. Did you get yours fixed?

doc, the fan will not come on until the engine temp gets past 240 degrees which is pretty high. I troubleshot that thinking it was supposed to turn on somewhere just over 200 degrees. Just an FYI

I have same problem with my GA 1995, 2.3, it happen only when I turn heater to the red zone,temperature increase up to 220-240, fan is running, but temperature doesn't go down. If I run without heater (blue zone), temperature OK. Thermostat is working fine. Liquid level OK.
Thanks in advance for any ideas
Vufu

I have an '87 Grand Am....runs like a sewing maching, but recently started overheating similar to what you described. If I accelerate suddenly from a red light, or even make a sharp U-turn, the needle will go back to normal temperature. I've replaced everything, the themostat, hoses, heater core, and lastly, the radiator! Even though it isn't the prettiest vehicle on the road with it's peeling paint and broken body molding, I'd like to keep driving the old thing as a backup vehicle. It's a shame to let her sit like this. I'll check the manifold and see if that is the problem.

I wish i had an absolute solution for you guys on this problem. I never did fully fix the problem. The final step I took was putting a new radiator in and having the system purged of air. My car still tends to run hot, but I've never had it red-line yet. But whatever you do, be sure to have it purged if you replace anything. You'll never be sure if you managed to fix anything if there's still air in the system.

Did you ever get that that water pump replaced? I ask because I had a bad pump[ the impeller was slipping and the coolant was not being circulated thus one hose hotter than the other at the rad. I replaced it with a remqnufactured one and it still overheated. I ended up putting on new head gaskets, put it back together and damn if it wasn't doing the same thing. I finally pulled the re-maned water pump and there was the problem, silpping impeller again. I broke down and put a brand new pump on and everything worked fine. For what it's worth you may want to check that water pump. You have a flow problem of some type unless you have the wrong thermostat. Years ago if we had a car that was running hot we would remove the thermostat and run an open system if it ran at normal temp we would know that it was thew thermostat not opening. That's all the ideas that I have, I hpoe this can help.