QuestionAbout a week ago I was driving with the AC on. I noticed that the air suddenly went to regular "fan" temp instead of cold air. I turned the ac off and drove back home thinking that the ac went out. I noticed that the temp rose. I have had this car since it's "birth" and the temp gauge has never moved past it's designated point. Once I got home I checked the coolant fluid. It was a little low in the reservoir. I added what it needed and drove the car again. It still over heated. When I first start the car the ac will work fine and the temp gauge does not show the car overheating. Once I drive the car, it overheats and kicks the compressor off to the ac. If i am driving the car and stop at a red light the temp immediately goes back to normal. The instant that I push on the gas to go it goes back up. I have to drive it with the heater on full blast to keep it from overheating. I think it may be the thermostat, so I checked it according to what you described by taking the cap off the radiator and watching the fluid flow. The fluid never flowed. It didn't bubble out, it just slowly rose out and the fans did kick on once the car reached normal temp. The coolant never flowed as far as I could see. The fluid just rose out of the radiator.
Now, my other thought is that the radiator may be clogged. However, i have never had it flushed. It has 70,000 on it. I do not believe that it is leaking fluid. Also, I have been told that it may be the water pump, or the sensors may be messed up. And you answered someone about their ac problem and mentioned an evaporator and a thermistor.
Does the Evaporator or thermistor have anything to do with my problem? I don't have money to replace all these things to find the problem. I need to know what order I should go in to solve this. Where are these "sensors"? Where is the thermostat? Is it normal for the radiator to clog up?
Also, it has never had a tune up. I got the spark plugs and stuff that it needs. I did not get the wires though. The guy at advanced auto said that it wasn't necessary for me to get them. Is that true b/c I don't want to hurt the car? What are coil packs? Does my car have them? Forgive my ignorance but the last time I had these problems I was dealing with a 1992 Ford Taurus.
I realize I've written a book but you seem to know your stuff and I desperately need help. Thank you, Lana.
AnswerIt sounds like you should start with the thermostat. Everything you list is consistent with thermostat failure. The thermostat is located in the housing on the engine where the lower radiator hose attaches.
You should also look in your radiator and check the filler neck for evidence of melting. The surfaces there should be nice and smooth. You should also check for gray material inside the radiator at the top of the fins. This, too would be evidence of the radiator tank melting. If it has, the plastic will get inside the tubes in the radiator and clog it and prevent flow. This won't occur at normal temperatures, but can if the car overheats.
Most of all, don't drive the car while it's overheating. You can cause radiator and engine damage.
Since your radiator fan is operating, we know that the coolant temperature sensor is working.
Your a/c will turn off automatically in the event the car is overheating. Once you repair the issues with the cooling system, the a/c system should return to normal. Don't worry about the evaporator, thermistor, or any other a/c part unless the a/c still doesn't work after the overheating is repaired.
The only consequence of not replacing the wires is that your car may develop a misfire if one of them fails later. This could hurt the catalytic converter if you drive the car while it's misfiring. But I strongly recommend purchasing factory wires if you decide to replace them. Your car does indeed have coil packs. If you follow the spark plug wires from the spark plugs, the other end will be at the coil packs.
