Yup, expansion valve. Some are louder than others and I believe there was a service bulletin out for those who complained about it.

I doubt anyone has ever objected to it enough to fix it out of warranty though.

 

Is it something that should be worried about?

 

No, it's just a noise issue.

 

Oh, well whatever then. Thanks!

 

I rarely have to turn my fan on higher than the 2 setting for my AC on my '08 Alpha H3x. Ice cold even on the hottest days.

 

Yeah mine sucks, but I don't think it is the AC that is really the issue. When it is on vent and full cool temp dial and the engine is cold, the air temp out the vents = outside air temp. When the engine is hot the air temp out the vents = +20 degrees higher than outside air temp. Something is wrong somewhere inside the air distribution system. GM repair docs say to check various things including checking the temp doors/seals/linkages - too bad they don't say HOW you can see those things and what parts you have to take off and where to get at that stuff. There are two temp actuators - left and right. I replaced the left one and ran a recal on the actuators - no change - both sides exactly the same higher temp, so I don't think it is the actuators (too bad - those are cheap and easy to change). Also don't think it is the control module because when you go full stop hot or cold on the temp dial you can hear the actuators grind at the very end - like they are fully closing/opening the temp doors. I ordered a USB borescope, when it gets here I will snake it through the vents and see what I can see.

 

I bought my H3 in the UAE where the temperature can get up to 48 deg C (that's errrmmm... very hot in Fahrenheit). It was winter at the time out there and the AC didn't feel super-cold, I thought it might struggle in the summer.

But when summer came it was fine, I'd usually have it on blower setting 2, with the temp setting as low as it goes and it would be fine - cool, but not exactly cold.