over heating

im lost working on a 94 grand am 2.3L . can't get the car to stop over heating. we have replaiced the water pump,thurmostate,radiator,radiator cap,machined the head,flushed the system and repolaiced the head gasket. The vehicle ran fine for a month and now it's back to its old tricks. :banghead:

I ran into this type of problem with a 1977 Olds Cuttlass, granted it is a completly different motor,but I can say that the problem I had would be universal. I went through the same regime, water pump, thermostat, machined heads, valve job, hoses,and radiator re-core. I put it all back together and on the test ride it boiled. I checked all of my work, and all was right from an external point of view. When I had a mechanic friend look at it he started it and got it to operating temp.(he left the rad cap off) Next he checked the rad to look for water flow (coolant level was below the core). He then felt the upper and lower rad hoses and found that there was a significant temp. difference between them. The diagnosis... a bad water pump! Yes I had replaced it but the new (actually a rebuildt unit) was bad, the impeller was not spinning wuth the shaft. I replaced it with a brand new unit and akk was fine.

I hope this helps, I'd look at the water pump or some of the other replaced parts. Or have the rad looked at for a blockage.

Good luck.

Aside from what Hoags said, is it possible you might actually be using the wrong kind of coolant? I'm not sure what the right type would be for your engine, but if your not sure it might be looking up. Just a thought.

Having a similar problem with a 94 3.1 L. Have replaced the thermostat twice, new water pump, flushed the radiator twice, new radiator cap. Car runs fine once in a while but usually within 10 minutes of start up starts overheating. Have to shut it off, can squeeze the hose coming from the radiator then restart the car and watch the temperature block. Was sure it had to be some kind of blockage in the radiator, a sticky thermostat, or air in the lines somewhere, but nothing seems to help. :banghead:

What about the engine collant sensor that clicks the fan on? Does the fan turn on when it seems to overheat? Do you get a warning light on your dash?

it was the water pump!!!
the after market one used to fix the problem the first time had small but noticeable differances . i replaiced with an nos part and the problem is cured.
shortley after i receved a flyer in the mail on the emergance of counterfit parts. aparently this is getting to be a problem and causing many headachs in the indestry.thanks agine for the help.

I just can't win with this car. Last year I had to have the transmission rebuilt, and the performance has never been the same since. It hesitates a lot, and now, I'm having a problem with the engine over-heating. When I looked under the hood to check the coolant, there was plenty in there, so I really have no idea what's causing this.

Yea i have a 1994 Grand am 3.2 and it was over heating like crazy and i did every thing and finnally the main hosing had a leak in it and that what was making my car over heat and the cap i changed.....And i wen't through 4 main water houseings and now i got the right one those keep braking on my car...Its working good now...My friend recieved 2 bad thermostates from the pontiac dealer they weren't opening

It's funny you should mention that, because my mechanic just replaced the thermostat, and the problem appears to be solved. Knock on wood.