[NikhilJ]

Hi all,

I have this very annoying problem. Under acceleration around 2000 rpm, the car makes a whistling noise. This sound is loud on cold days and not so much on warm or have been driven for 30 mins or so.

Also, I have to top off oil every 700-800 miles. Not sure if these are related or not.

Spoke to the dealer and got the standard answer, its turbo spooling.

Has someone experienced the same problem?
Please help!! Its really annoying and have been struggling to find a fix for last 18 months.

Its 2007 335i with close to 78k miles.

thanks.

[Muwiee]

There can really be multiple things with your car. From the A/c fan or hood cowl coming up or needing replaced. . As far oil you're oil filter gasket probably needs replaced bc it goes bad a lot. It's not easy to spot bc it's normally on bottom also some guys have had the actual oil filter gasket go bad. Bc of the engines high normally operating temp these things will happen.

[NikhilJ]

I dont think its A/C fan because it sounds even the a/c is off. Seems like something to do with air leaking when it tries to suck in more air to accelerate. No expert but need a fix

[ashmostro]

A full quart every 700 miles?

[NikhilJ]

Yes. Hard to find anyone knowledgeable.
Dealer says its common, 335i operates at high temp so burns more but that was not the case few years ago.

Does anyone know a good shop in CNJ?

[ashmostro]

That's pretty high even for an n54. Whistling during cold weather driving before fully up to temp is normal but the combination of whistling and high oil consumption suggests you may have a turbo or two needing attention. Get it checked out by a better shop to be sure.