I have a 94 Grand Am SE 2.3l Quad 4. I replaced the heater core about a week and half ago. After Replacing it and hooking all the hoses. My Dad drained the Jug on the side of the Radiator ( I dont have an old fashion Radiator. It dosent have a cap on the radiator, it all goes thru the jug on the side) After that The low Cooliant Light came on and it began to over heat. A friend said it was " air Locked" the next morning we messed with it, squeezing hoses and such and it began to run at normal temp (between 190 to 200 degrees) but with the heater on it runs at 220 degrees. Today I was driving to town after drivng about 5 miles it began to heat up. I turned around and went home when I started up a hill it got up to about 260 degrees when going down the hill it cooled down to about 220 degrees. I stoped at the store and when I left the store the faster I drove the cooler it ran (until the transmission shifted). In total I drove the car for about 15 minutes. When I got home I opened the hood to see if I could see water leaking. I could hold my hand on top of the motor, it was cool like the car had never been started. What could be the problem?
Start by making sure you hookted all the hoses up where they started from you may have put them on backwords
February, 17, 2006 AT 7:20 PM
They are all hooked up correctly. I test drove a 1997 Grand am a bout a week before I bought the 94 it did the same thing, and it turned out to be a stuck thermostat. Could that be the problem
February, 18, 2006 AT 4:16 PM
I had the very same problem with my 1995 Grand Am. I changed out the thermostat, and heater core, check to see if the cooling fan was working, (it was) and still had the same problem. I have a good friend of mine and great mechanic check it out because I too was stumped. It ended up being that the head gasket was cracked. Even though it showed no signs of a bad head gasket. Coolant in the oil, etc.
I had him change out the head gasket for me since he had to tools for it and have had no problems since. Though it will heat up while idling, but will cool down once driving getting the air through the motor. It does NOT over heat anymore.
It was a last resort having the head gasket replaced FYI.
February, 21, 2006 AT 2:30 AM
Yup, time to do a leak test on the coolant system. Also, pressure test the system and make sure it is at optimal pressure. You have a gravity system, this means older ways of testing the coolant system will not work.