I just purchased a 2002 Pontiac Grand Prix. I runs hot...I think. I*m not sure if it really is or not because it goes up and comes back down. Driving interstate speeds or at a stoplight, it just kinda does what it wants. No leaks that I can find. Popped up the low coolant light yesterday, by time I pulled over to check the light went off. Happened twice today. A/C also cut off on it*s own and came back on. Is my car possessed? Or did I just get hosed by the dealer? Thanks a bunch.
Sounds like you may be low on coolant. This could be just because it hasn't been topped off lately, or you could have a leak. The level of the coolant fluctuates with temperature change and that's most likely why your light goes on and off. Never open the coolant system when the car is hot. However, if you know where your coolant reservoir is, take a look at it first thing in the morning. It should be marked where the level should be at cool. I wouldn't drive too much with it in this condition, as high temperatures can do a lot of damage to your engine. You can take it to your mechanic and have the fluids checked. Ask them to do a quick pressure test on your coolant system to make sure you don't have a leak. As for your a/c cutting off, that's a protection device that most cars have to try to keep the engine from overheating. I'm almost positive that once you get your coolant problem is solved, your a/c problem will stop.
〉 Answered on Jun 12th, 2007 by Suzanne Grego, Technician at City of Philadelphia Fleet Management