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Car Overheating

I live in Phoenix. When temps rise and traffic stops, do I need to turn off my car airconditioner to avoid overheating the engine? I have a 2003 Toyota Highlander and a 2004 VW Toreg. Thanks!

No, you shouldn’t have to turn off your AC. When the AC is operating the radiator cooling fans are running, too, to help remove the additional heat. A properly functioning cooling system should not be overburdened by the operation of the air conditioner, even in stop-and-go traffic.

Let’s turn the question around. Are you saying that your cars are overheating when the air conditioning is on?

I’m concerned that they may overheat if I let the air run. In Phoenix it can get to 110-115 degrees in summer. Last week I got stuck in accident traffic, 114 degrees and sat for about 30 mins with the air turned off. Was that necessary? Getting stranded in that type of situation can be deadly (also had my puppy with me).

If these vehicles have been properly maintained, and if their cooling systems are working as designed, you can operate the A/C even in those extreme conditions. However, you would be well advised to keep an eye on the temperature gauge. If you see the temperature beginning to rise above…let’s say…the 3/4 point on the gauge, then it would be best to shut down the A/C right away.

And, in a situation where you have to cool down the engine, turning on the heater will actually draw heat from the engine. I am not saying that this would be a good thing to do, given the ambient temperature that you noted, and especially if you have a dog with you, but this is something that you might want to store away in your memory bank for future reference.

I agree as usual with McP and VDC. If the car is running properly and has been properly maintained you should be able to run it with the AC engaged without incident. Remember that although 114 seems hot to us, the engine’s normal operating temperature is over 200F.

However, I also agree that it’s a good idea to keep an eye on the temp gage. If it does start to climb too high, the AC can always be turned off.

By keeping that wary eye, you can keep the AC running with confidence…you’ll be able to prevent any problems long before they develop.

stating the obvious…have you checked the level of coolant in the radiator…and is the AC fan running when AC is on???