So I've been noticing the past month or so (since we got to SoCal), that every time I start the car and turn the AC on it sounds almost banshee-ish when I give it some gas during acceleration. I also get the noise when I downshift and am engine braking, all the way down to about 2,500-3,000rpm. I know my air filter is dirty, negotiating with the wife on doing quite a few things at once to this girl lol, including all filters and spark plugs. Is there anything else that would cause that? Doesn't seem to affect performance (it's a total dog when the AC is on), just sounds odd. Just wanting to know if anyone else has ever had this happen. Thanks in advance!

-Mike

 

I've actually experienced this exact same noise with the a/c on for last month or 2. It sounds like a howl with the engine under load at about 2500-3000 rpm. It happens in every gear so its definitely related to engine speed and not the overall speed of the car.

I have replaced my air filter, spark plugs and serpentine belt so I don't think its related to those. It almost sounds like a bad bearing. If I had to guess, I would say its a pulley bearing on one of the accessories. I've never experienced a failing a/c system before so I don't know if it would make a noise like this, it still blows cold though. I have had some alternators and tensioner pulleys fail on other cars and they can make some bizarre noises at strange times

 

Mine does this too. Maybe nature of the beast. Everything runs fine and get cold air in our famously hot S. Carolina. (Not as hot as AZ these days ;>) )

 

Simplest cause would be insufficient belt tension. When there's a load on the belt (accelerating or applying compressor load) it slips. Check the age of the belt and the tensioner.

 

My belt is only a year old... Good tension. Almost sounds like there's another fan whizzing along when AC is on.

 

Mine makes the same noise with the AC on.....even after a new belt and tensioner. I think it's just the nature of the beast.

 

Its makes noise on my R52 cooper also, steady . If it starts to chirp or squeak then its the belt.

 

hah, I have the same problem, and was wondering if the compressor was starting to go, funny thing is, mine only does it when its warm outside to justify it the AC, if its like 60 deg or under it doesn't make the same noise. actually almost none at all.


I am wondering if its just the compressor wheel moving and making that noise. mine only happens above 2800 rpm