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Well I am stumped. I have a 1998 Pontiac Sunfire (2.2L) that is overheating. Here is a list of new parts, Radiator, Head, Head gasket, Water pump, Thermostat, and Temperature Sending Unit. And i have bled the system 3 times. The only thing NOT new is the hoses. It's weird because the car will idle all day long at normal temp, but when I take even a short drive the temp starts rising almost instantly. Even with the gauge reading almost in the yellow, the coolant in the reservoir isn't bubbling, but it is hot. Any suggestions would be great. Thanks,
Will  

Well I am stumped as well My daughters 97 Sunfire has the same problems, and we have did everything that you have Head, head gasket,water pump, thermostat, new radiator, vacum bled the system 3 times. some kind of circulation problem engine gets hot but the rad never does. It will also idle all day with no problems but overheats on the road???? Did you figure it out yet? Any suggestions for me  

did you put the thermostat in backwords? only thing i can think of.  

Check to make sure your egr is working properly... I'm conviced thats your problem, Your egr recirculates burnt gases while your driving in order to lower the engine temperature  

I have a 97 Cavalier 2.2 and I have a very similar problem that has stumped 5 different mechanics in the city where I live.

It started with the car overheating (not into the red but very high normal) then the head gasket blew out, got the gasket replaced and the head checked for warps/cracks and there were none. The car still overheated after the new gasket, so they replaced my radiator, thermostat, water pump and in the process bleed the cooling system like 5 times! The car doesn't always overheat, it seems almost random... and when it does overheat, if I slam the gas pedal to the floor (usually in anger over my POS car not working right) the temp comes back down to mid normal... I'm baffled.

Have not checked the EGR, I'll get that done this week.

Any more ideas?

Thanks

Ed  

You can get erratic reading if air is trapped in the coolant temp sensor fitting. Use a backup wrench on the inlet pipe fitting and back the sensor off until coolant weeps from the threads and then retighten the sensor until a 5mm gap between the sensor hex and inlet pipe hex.  

try  replaceing the lower rad hose
the hose looks good but when heated the force of the water pump collapes the hose in higher rpms  

Sorry for taking so long to repost..had major internet issues at home...
But anyway I still don't have the problem fixed, but we can add one more part to the list, the metal coolant pipe that runs from the head to the upper radiaitor hose was in pretty bad shape and I replaced it. Still no good. The car's temp will rise (even at idle now, with heat on full blast) but not "overheat" then it will randomly go back to normal and then back up. The cooling fan is working properly. The coolant does not bubble up in the reservior bottle either. The weirdest part is the rubber hose connected to that metal pipe is hot near the pipe, but not near the radiator. Also coolant is flowing...when I rev the engine you can see it come up in the reservoir bottle, then go back to the normal level when you let off. I really don't understand. I will change egr just for kicks, I am out of ideas.  

Ok, so today I got the bright idea to bypass the heater core and see what happens. Well guess what....problem gone. I guess I need to buy a new heater core now. Maybe someone with a similar problem might want to try this. Take out the metal pipes that run to and from the heater core and cut the short one off (The pipes are brazed together and mine were in bad shape and need replacement anyway) Use this short pipe to connect the hose from the back of the thermostat, to the upper radiator hose.(You have to turn the rubber hose on the upper to bend toward the front of the car) Clamp it down, refill coolant and off you go. My car kind of sputtered a little bit when I did this, so I'm going to just replace the core and those 2 pipes. It takes a little while to get it done, but it's worth not having to spend a ton more cash. Hopefully this can help someone out.  

hello can anyone help i have a 97 with a 2.2 and i cant get the fan to work the fan is good so are the fuses and and relays and temp sensor the fan should come on when you turn on the a/c but it dont no power to the plug any ideas. thank you  

My experience with GM condenser cooling fans , is that the high side pressure switch has to be activated to turn on the fan /fans. Around 180 to 200 psi. on the high side. Is that the fan you are having trouble with? or is it the coolant fan? If it is the a/c condenser fan , check the high pressure switch.  

hello and thank you the reply but there is only 1 fan on these cars for cooling and a/c it is supposed to come on as soon as the a/c is turned on and it wont work that way or with the car just running and coming up to temp. thank you  

put the thermostat in backwords?

put the thermostat in backwords  

DUDE ,,, the way this steel pipe is made that comes off the thermostat,, it is impossible to put the thermostat in backwards.  

i have a 1999 pontiac sunfire i have changed the thermostat,waterpump,temp sensor and athe fan relay. its still overheating when im driving but not when its sitting still? theres no water in the oil,or smoke frm the exhaust. if any1 has any ideas please let me know asap. thank you very much. <a href=http://www.sbsrv.com>Keystone rv</a> in FL