Whistle noise in engine

[AlpWhitE46]

It starts happening around just about 2k RPM...

it doesn't always happen when i start the car and drive.. but about 70% of the time and it will start from the time i drive off... and might go away later..

Someone help please? Thank you


secondary air pump?
or
idler pully and tensioner?
http://www.2shared.com/video/YnS_NxG...720-00004.html

[SiR]

secondary air pump is only on when the engine is cold and for about 2 minutes? Its also not attached to the drivetrain via any belts and wont fluctuate with the revs like the sound you have does.

that sounds a lot like power steering pump whine

bust out a long screw driver and start listening(careful not to get it tangled in anything spinning)

if you turn the wheel does it whine?

[AlpWhitE46]

Im 99 percent sure its not the steering pump
it has nothing to do with turning the wheel

[SiR]

if its doing it when the engine is warm its not the secondary air pump.

Other belt driven accessory that can whine is the alt.

If its not whining when turning Id lean towards the alt pulley;s or the alternator itself.

[Blades]

air vacuum leak somewhere in the intake or after the intake?

[fitter527]

Originally Posted by Blades

air vacuum leak somewhere in the intake or after the intake?

what he said.my car was doing the same thing,replaced the rubber boot.

[MANDD]

Could not load the clip provided however the most common cause(s) of this noise is,

1. Throttle tube elbow. Usually cracks and causes an air leak at the small tube to idle valve causing whistle noise on moderate throttle application at 2000rpm. This can be seen visually. (BMW 13 54 1 438 759 for 3.0 motor) or (BMW 13 54 1 435 627 for 2.5/2.8 motor).

2. Deflection pulley (at alternator). Bearing usually fails this noise is typically present from a cold start and may dissipate after a short period. (BMW 11 28 7 841 228).

Mark.