1992 Pontiac Sunbird OverHeating Problem

Home  \  Repairs & Maintenance  \  1992 Pontiac Sunbird OverHeating Problem


My name is Richard.

I am having some trouble with a 1992 Pontiac Sunbird. It have a very strange overheating problem. The car will run fine for a little while the engine will heat up and then the temp goes back down. And then after about an hour or two. The car will start to overheat. There was a few leaks that I took care of already.

I have replaced the Radiator, Themostat (2 actully), Water Pump, all of the hoses but one. As far as i can tell there isn't anything leaking from the car. I did noticed today that, I was looking at the tail pipe and there was a little bit of white smoke coming out. I also noticed that it was dripping water. I am now starting to think that it might be the head, or a headgasket job, however is there anyway to test for that. I don't want to pull apart the engine just to find out that isn't the problem.

Thanks in Advance,


Edit: Type of engine is the 4 cylander 2.0 L engine.

posted by  rich221976

Well there's not enough info to make a real recommendation so I'll go with what I can. It would certainly help to know if the coolant level is going down and if so how much. It doesn't sound like a head gasket to me simply because you said the temp will go back down, I assume to a normal temperature. The easiest way to check is to do a compression check and also a cooling system pressure check. Between those two, you should be able to nail it.

My call from your description is you have a problem in the cooling fan circuit. Fan, relay, coolant temp sensor, wiring, maybe just a fuse. If you took your car to a qualified tech to begin with I'd be willing to bet it would already be fixed for about the price of your new radiator. You have just learned a valuable lesson about playing Russian Roulette just replacing parts instead of troubleshooting the problem.

posted by  vwhobo

Everything that has been replaced in the car was actully bad. The radiator had a pin hole in it, and the hoses went one by one. They actully explodied. I did forget to add that i replaced the fan motor as well since that died as well. The car runs fine for about an hour, and then it goes up into the 260 mark on the temperature gadge. Once that happens, then i have to let it cool for about an hour and then it runs fine again. The water level does go down after awhile. Also another thing before i forget. When the car is running, I can actully see tons of air bubbles in the resverse tank.

Anymore information you need from me just ask.


Edit: Also the fan is running when the car is overheating, and the air coming from the fan is cold air.

posted by  rich221976

Two words. Head gasket.

posted by  vwhobo

sounds like you might have an air pocket in the system somewhere...
when the bubbles are coming out of the reserve tank, is the cap on?

how long has this been going on? is this just shortly after the swap, or has it been going on for a while?

posted by  asa67_stang

I experience a similar problem with my Pontiac Sunbird 2.0 L engine. Occasionally, my engine will heat up until close to the read zone, and suddenly the temperature will drop back to normal. Sometimes this problem won't occur for a whole week, than it occurs twice in a day.

I have to fill cooling liquid more frequently now, but do not observe any leaks.
Any advice on how to solve this problem would be appreciated (and I can supply more information on the symptoms as needed).


posted by  Majto

Gosh, critical technical information is so nice....... :banghead:

If you are losing coolant then it is going somewhere dude. Either you have a leak and if that ain't the case, you are consuming it. If there are air bubbles in the coolant reservoir AND you notice that you are losing coolant and it is not dripping under the car or leaking anywhere, you have a head gasket blown. The air bubbles are the engines compression leaking into the cooling system. Run a compression check on each cylinder and then pressure test the cooling system. As VWHOBO stated, HEAD-GASKET!

As for you Majto, it seems like you cannot read from the previous postings :screwy: I think we've just hit your problem in the head too.....if it ain't leakin baby, and the levels is going down, that means only one thing......you're burning coolant. Do you have a little or a lot of white smoke periodically or all the time from the tailpipe? That's classic symptomology.

posted by  cmeseadoin

Asian........answer me this genious :screwy: ......if there is a loss of coolant being experienced and there are air bubbles in the coolant recovery tank, how does air pockets come into play with being the root cause? Explain where the coolant is going? If you had air pockets you would have other problems EXCLUSIVE of losing coolant from the system without a leak in sight. You might have no heat because air is blocking coolant from the heater core or you might have the thermostat not opening/closing due to the air in the sytem which would need to be bleed. You could even have an engine over/under heating situation because the cooling system is not functioning optimally. If he is blowing bubbles in the coolant recov. tank, NO SHIT there will be air pockets in the system, you're losing compression from the cylinders of the engine right str8 to the cooling system. :banghead:

Stick to your day job or exposing your ass such as your avatar on here, car techie help ain't on your horizons. :laughing:

posted by  cmeseadoin

Hello, i'm sure Richards problem has been fixed by now, but reading these replies motivates me to leave another, possibly more informative answer. A lot of those Pontiac 2.0L head gaskets seem to break between the #4 cylider wall and a coolant passage located very closley towards the front of the car. What happens is that when the cylider pulls air in on the intake stroke it will suck coolant in as well. When that cylider fires the antifeeze is burned and it produces a white smoke. This also occurs after parking the car over night and small amounts of coolant trickle into the cylider. When richard says that he saw white smoke, then coolant is being burned. Most of the time it is this head gasket that has been blown. However, sometimes cylinder head warpage, a cracked head, or even a cracked cylider wall will cause these same symptoms. As for the tempurature flucuation, the hot exhaust gases are forced into the cooling system. These gases are extremely hot and in a normal running engine, this heat energy is passed through the exhaust system. In this head gasket senario, some of the heat is transfered to the coolant, causing the car to over heat. There is a way to test for this. A tool is sold that screws onto the radiator cap. This tool holds a liquid that will change color if exhaust gases are present in the cooling system. However, on a more severe head gasket failure, those exhaust gases are just that, gases. They will find their way to the top of the cooling system in the form of small bubbles to major eruptions through the radiator cap. Look for them, if there are bubbles, you have exhaust in your cooling system. As for the air pockets senerio, this is a very likely problem with cars that recently had a thermostat, cooling flush, or any procedure that would drain the coolant past the water pump. If there is air around the pump, the obviously the pump wont work. However, this probably isnt Richards problem due soley to his observance of the white smoke. Whew, make sense?

posted by  hi.alt.perform

Your Message