I have a 2007 HHR LS with 44,000 miles on the odometer. I bought it new. During cold weather, there is a definite "whine" sound from under the hood. The colder the temperature, the louder the sound. It goes away completely when the engine has been on for a few minutes. It began after about a year of ownership. I just got the car back - it was on loan to one of my sons for the last two years - and the whine is louder than I remember it to be. It has never caused any problems.
What I would like to know is - what is making the noise? It is the kind of noise that a power steering pump would make - except the HHR does not have one. I would think that the alternator would have self destructed sooner, owing to the long-standing nature of the noise condition. That leaves the AC compressor, assuming the noise is being generated by something external to the engine.

Any possibilities/probabilities you know of?

Willie R.

 

transmission? It does whine a bit when it's cold out until the car warms up.

 

I guess the question is whether you're hearing a mechanical whine or a squeal from a failing alternator bearing or AC clutch. The 4T45E auto trans seems to whine a bit when dead cold, both of mine have just the slightest whine for a mile or two when cold. Does the whine vary when the transmission shifts, or does it vary with throttle position? If its a trans whine the pitch should change with the shifts up through the gears, louder in first and then dying out through second, third, and so forth. A bad AC clutch or alternator should increase its pitch with the engine speed, more throttle = more noise. In my case the whine is so soft I have to turn off the radio to even hear it, and I've had GM transmissions with the same cold whine. If its possible have someone rev the engine while you listen with the hood open, and also have them turn the AC on and off, a bad clutch will make itself readily apparent as it cycles. Of course you can always take it in and have it checked over by the techs at your dealership.

 

if its the same intermittent whine im thinking of, ive heard a few reports of it with the ecotec 2.2. Had it in my hhr and previous cavalier, assumed its just a trait of this engine.

 

I did forget to mention that my HHR has a 5-speed manual transmission.

 

pretty sure it's a common thing...mine does it too (will again here in a few min when I leave). Not terribly sure what it is, but it goes away.

 

My 2007 has done that since it was new. Its no worse now than when I bought it, and it quiets down as soon as it warms up. Mine too is a five speed, so its not a transmission noise.

 

As its in the single digits here I get that whine to, from my experience it sounds like a power steering pump whine, But as we know we don’t have one. As my hhr warms up it goes away so I am not alarmed by it. I think it’s the tensioner and belt just being cold.