[insanesam]

Hi

Have a 2008 335i e92 Manual (210000km). Recently noticed a whining noise on deceleration (irrespective of gear and speed) when engine rpm is around 1500 rpm. If I clutch in and hold the throttle at 1500 rpm the sound goes away which implies it has to be under load.

If I simply rev the car to 1500 rpm at idle then no noise. Although the tensioner/pulleys/belt were replaced about 60000km ago they still feel smooth and no noises. The alternator pulley however was noisy and felt gritty when spun. So the assumption was the alternator pulley. I replaced it today but unfortunately the problem remains.

Anyone run into the same problem or have any suggestions?
Car drives perfectly fine with no codes.

Thanks.

[Bimmer_Bro]

[QUOTE=insanesam;30998638]Hi

Have a 2008 335i e92 Manual (210000km). Recently noticed a whining noise on deceleration (irrespective of gear and speed) when engine rpm is around 1500 rpm. If I clutch in and hold the throttle at 1500 rpm the sound goes away which implies it has to be under load.

If I simply rev the car to 1500 rpm at idle then no noise. Although the tensioner/pulleys/belt were replaced about 60000km ago they still feel smooth and no noises. The alternator pulley however was noisy and felt gritty when spun. So the assumption was the alternator pulley. I replaced it today but unfortunately the problem remains.

Anyone run into the same problem or have any suggestions?
Car drives perfectly fine with no codes.

Thanks.

Is your AC on when you are hearing this? Will it also do it if the AC is off?

[insanesam]

Noise remains with both AC on or off.
I managed to record a clip
https://www.youtube.com/shorts/J669fw466A8