WHAT CAUSE A RATTLING SOUND WHEN YOU TURN ON YOUR AIR CONDITIONER on 2006 BMW 325i

wHEN I TURN ON MY AIR CONDITIONER YOU HEAR A RATTLING SOUND FOR THE OUTSIDE OF THE CAR. WHEN I TURN IT OFF THE NOISE STOP.

by in Saint James, LA on June 10, 2010
1 answer 1 comment
ANSWER by on June 11, 2010
Thank you and well done for narrowing down the symptoms. Does the noise sound from inside or outside of the car? It could possibly be a noisy compressor or a power steering line rattle against one of several brackets, when the rpm rises as A/C is selected. I have had other things causing rattles such as the tensioner and pulley assembly which was only heard with a/c on and applying slight load such as putting in D and turning the steering wheel. Also possibly the A/C compressor tensioner and pulley assembly or the fuel vent line can also create a rattling types noise at a certain RPM. Good luck
COMMENT by on June 16, 2012
Hey, I am having a similar problem- but here is some more info. My AC makes a rattling noise (outside) when it is on and the car is in park or reverse. When I accelerate to a normal driving speed- there is no audible noise. It has become so bothersome that I turn the AC off when I pull up to a stop light because it is embarrassing. The air cools just fine though.