1996 Olds Cutlass overheating

[haroldms3]

I have a 1996 Oldsmobile Cutlass Supreme 3.1 L that has had overheating problems for the past 2 years. Ever since I moved to Colorado. I replaced the radiator 2 years ago, and replaced the head gasket, thermostat, and water pump last September. Now the car overheats in the city after driving just a few miles. Hoses seem to be fine and I recently replaced the radiator cap. Coolent boils over after driving a few miles, but the overheating is not consistant. Sometimes I can drive with the AC at full blast with no problems. Other times, the car overheats after 3 miles of stop & go driving without AC. When the car gets into the red, the heater blows COLD air???

Any suggestions?

[ohenry5]

From what you said in your post i came to this conclusion, not sure it is correct but its worth a shot. You said it doesnt overheat with the A/C on but it does with the A/C off. With the A/C on the cooling fan will run constantly, hense, keeping the car cool, with the A/C off the fan will not run and only come on when the car gets hot, so it sounds to me like you have a problem with your cooling fans, either the relay is bad, or the fan motor, something along those lines. Check to see if the cooling fan is coming on at all, if it doesnt thats your problem. Hope this helps.

[haroldms3]

You said it doesnt overheat with the A/C on but it does with the A/C off.

Actually, the car overheats no matter if the AC is on or off. I just wanted to make to point that it doesn't seem to be the fans, because both fans are running while the car is running hot.

Thanks for the advice though.

[jnoinky]

my 94 olds had a similar problem...I changed thermostat, fan motor, water pump was good, changed cap, etc, turned out to be my heater core...if you have even a small leak in a heater core it will overheat...With a bad heater core, you may or may not see these symptoms: smoke from vents if bad enough, windows won't defrost, smell antifreeze...would also check your cooling fan though..A good test for that is to turn your ac on full blast and check to see if your fan is running...Fan should always run when a/c is on...if it's not running then it's your fan motor or relay.