Whistle under load, any ideas?

[Mr_Sukebe]

My 2002 330i sport has apparently started whistling (according to the missus, but she has better hearing that me). She (badly) tried to describe the whistle as a kind of high frequency rustle.
Only does it under load (constant or acceleration). If you put the box into neutral and coast, the noise goes away.
That suggests to be that maybe it's the diff.

Any thoughts or suggestion?
If it is the diff, are they sealed units?

[john_p]

Mr_Sukebe said:

My 2002 330i sport has apparently started whistling (according to the missus, but she has better hearing that me). She (badly) tried to describe the whistle as a kind of high frequency rustle.
Only does it under load (constant or acceleration). If you put the box into neutral and coast, the noise goes away.
That suggests to be that maybe it's the diff.

Any thoughts or suggestion?
If it is the diff, are they sealed units?

Surely it's gearbox/clutch related if it goes away when you're in neutral?

How many miles has it done? Manual / auto ?

[AdamD]

It could be the 'ghost whistle' which affects some M54 engines, sometimes the rubber air inlet hoses around the throttle body can split and cause a whistling sound under light throttle applications. Its certainly worth a check although you might need to pop them off to have a good look up close.

[Neil_Sc]

Torn intake boot?

It is a common failure, trace it down where it goes into the throttle body and Idle Control Valve, usually the smaller pipe going to the Idle Control Valve is torn.

It's a pig to remove as in the factory the bellends fasten the jubilee clips upside down.

[Beamish]

+ 1 for the intake boot.

Had it myself recently, nearly drove me mad 'till I found the split in the pipe from the boot to the idle control valve.

Enjoy !

[silverback mike]

ahhh, mine does this too when giving it some beans...I shall investigate my pipe also

[neil_bolton]

silverback mike said:

ahhh, mine does this too when giving it some beans...I shall investigate my pipe also

Intake boot was replaced by Clayton on yours on its major service. May be gone again, but I think its more to do with the 'ahem' filter on that one

[Mr_Sukebe]

Thanks for the suggestions chaps. I'll get that checked out over the weekend.

BTW, my car is an auto with 114k on the clock.

[M3John]

I'm glad you've asked this as my e36 M3 does this too. Would it be the same fault ?

[theboymoon]

neil_bolton said:

silverback mike said:

ahhh, mine does this too when giving it some beans...I shall investigate my pipe also

Intake boot was replaced by Clayton on yours on its major service. May be gone again, but I think its more to do with the 'ahem' filter on that one

yours used to whistle quite a bit

not that you ever passed me at max leptons 6am on the M4 one morning, no no no.......

Edited by theboymoon on Friday 16th October 14:12

[Hugo a Gogo]

so it whistles while it works?