BMW 528 whining noise

[cyborg]

My bimmer is well serviced and carefully driven and whenever I start the car nowadays I hear a whining noise little after I start moving the car from engine that stays for a short while and get disappear after few seconds. Sound is whistling and whining mix together. It doesn't come after that during whole drive and comes only once after the car start moving.

Though it doesn't bother me much, but better ask and see the issue in case if I can fix the bigger problem in advance. Thanks guys, have a great week ahead.

[mark]

Sounds like a whin from some belt especially AC compressor side, I think in bimmer's there is only one serpentine belt unlike japanese cars, where each component runs on a separate belt. Try spraying some water or WD40 on that belt after starting the car and then drive off and see if same whin comes or not....? If it doesn't it means belt need a replacement and if it's still whin my second doubt is AC compressor is getting old and scream when cold (more expensive than belt replacement). Good luck.

[ethan]

Your BMW has single serpentine belt not multiple if it's newer than 2003, as older model has separate belts sometime in 90's model.

[mum65]

Dont put anything on belt it might be risky. Just get the belt changed. That would finish the noice. 

[mark]

Dont put anything on belt it might be risky. Just get the belt changed. That would finish the noice. 

What I meant is only for testing and spraying water or WD40 is not bad or risky to test if belt is the actual culprit. When belt rubber dries up it makes this squeaking noise, and when water or WD 40 sprayed it will moist the rubber for 15-20 minutes in proving the belt change is must or not. We don't know the actual noise and it's hard to comment 100% without hearing anything.