My 2008 HHR overheats sometimes when the A/C is running. Add soon as I turn the A/C off it starts cooling down and running at normal temp. Also once the A/C is turned off there is a noise from under the hood. Not sure how to describe it. The coolant level is good. There are no signs of any leaks. The air does get cold when it isworking. But gets hot once the car hits cooling mode. It's been making the noise longer than the over heating. The fan also stays on one the car is off sometimes. Thanks in advance.

 

Have you checked the other obvious items:
- coolant level correct?
- does the rad fan(s) come on as soon as the a/c is switched on?

And can you describe what leads you to think it is overheating? What does the digital temp display read at normal (without A/C on), and once the A/C is on and it starts to overhead?

 

The display shows the temp at 260. The fan does come on when I turn on the A/C

 

When ac is off it reads 200-210

 

- coolant level correct?

 

Yes. And the noise isn't the noise like a water pump or bad pulley, belt

 

Is the noise constant when the engine is running, or only when the A/C is on?
(sorry, got hung up with a couple phone calls)

 

Here's an interesting thread about a noisy water pump - https://www.chevyhhr.net/forums/prob...mp-gone-26225/

 

It's constant when ac is off. Thanks I will look at the link.

 

Old-school trick to isolate the source of a noise internal to the engine: grab a BIG ol screwdriver, hold the end of the handle tight to your ear, and put the tip of the screwdriver tight against the engine here and there - it will help pinpoint the area where the noise is coming from. Of course you have to be careful where you place the tip. Might be a helpful way to diagnose a water-pump issue.

If it is only when the A/C is off, I'd suspect the clutch in the A/C, belt or tensioners. But I don't see how they would be related to it overheating.