I currently have a 05 cooper s and I started to notice when I turn on the ac everything under the hood seems to get louder and it sends a weird vibration through the car. Also starting to notice when the car is idol the rpm just seems to jump and drop. At times almost stalling on me. Anyone have any advice for me or even if the problems can be related so If I need to take it to a shop I have a better way of explaining it to them.

 

Is a 2005 GEN-2 (I'm not sure)? If not, this is the wrong forum...

 

Yeah it is not 2nd gen. Sorry bout that

 

2nd gen starts in 07, 05-06 is just a face lift of the first gen not a model change

 

To answer your question, it sounds like you have a problem with the idle speed setting of the engine; might be a sensor, or something to do with the ECU. It's entirely possible that the noises are the engine being lugged down by the load of the A/C compressor.

There's also a chance you have a problem with the A/C compressor itself. If it's going bad, it could draw more power from the engine than expected and cause these sorts of problems, but only when the A/C is on.

 

Thanks a lot for the info. At least I got an idea on what should be looked at