Ok guys, I'm a Chevy guy myself, but my wife has a 2009 Mazda 5 wagon/minivan thing. Automatic, 4 cylinder. For quite a while there has been a noise from under the front right of the car. Under heavy acceleration such as going up hills it's makes all kinds of noise and often sounds like the car is missing on 1 or 2 cylinders but with no loss of power. Car just gets super loud then starts cutting out. Sounds exactly like when my old supra would lose fuel but no power loss on the Mazda. The noise mainly seems apparent when the AC is turned on. Car is quiet in park or neautral but as soon as it's put into gear it gets louder. Turn the AC off and goes normal again. Only visible damage to the car is the plastic between the motor and road is busted up from where she constantly runs over small animals but the noise doesn't get worse at high speed, just under higher RPM's. I'm pretty much at a loss other than possibly the tensioner pulley? Any help would be great as I know nothing about mazdas.

 

So, its only noisy with the A/C on? Might be time for a new compressor.

 

Yea but even then only when the car is in gear and the AC is on. That's what has me stumped because I can't think of a single thing that would link the air conditioner to the transmission.