[Bimmer_Engineer]

So I’ve got a 2007 335i with 96k miles...no wastegate rattle...hits boost targets...turbos spool well...tuned for 5k miles. I was on mhd 1+ v7.0 and I started to hear a whine at part throttle starting around 2,500 rpm. When the throttle is full open the drivetrain noise is too loud to hear it. I know the turbos sometimes start to whine when they’re on their way out...but does 96k miles seem a little early for that?

I retuned to stage 0 today and don’t hear any whine...is it possible I’m just hearing the turbos spooling to a higher rpm on stage 1+? Or do y’all think my turbos are going???

[Chris@VargasTurboTech]

Do a boost leak check, change your oil often, and don't worry about it sir.

[Bimmer_Engineer]

Originally Posted by Chris@VargasTurboTech

Do a boost leak check, change your oil often, and don't worry about it sir.

Thanks for the feedback...I change my oil often and I don’t have any leaks...

[Moisture]

With your car running look at the belts turning on the pulleys, particularly the belt tensioner. Notice any wobbling or do the belts spin straight and true?

[Bimmer_Engineer]

Originally Posted by Moisture

With your car running look at the belts turning on the pulleys, particularly the belt tensioner. Notice any wobbling or do the belts spin straight and true?

That’s a good thought but I recently did the belt and pulleys and they’re all good. Also when I tuned to stage 0 the whine went away.

[Moisture]

Originally Posted by Bimmer_Engineer

That’s a good thought but I recently did the belt and pulleys and they’re all good. Also when I tuned to stage 0 the whine went away.

The sound could be a multitude of different things. most likely just an old/noisy/seized bearing somewhere.

Or maybe not. It's hard to pinpoint. As long as you're not excessively hard on the car I wouldn't worry.

[924er]

My turbos have a slight whine when cold which is more profound with DPs installed. It still hits boost well and I have no leaks that I know of.

Once the oil temps are up, the whine becomes more suttle. So it might be normal as plenty ppl on the forum have whining turbos. Now a siren is different esp with white smoke lol

[Bimmer_Engineer]

What does the siren indicate? White smoke out the exhaust? I’ve had a smoking issue before...cleared up with some at205 added to the oil.

What I was hearing sounded like spool noises just louder than before...it could have been described as a very faint siren...

[JM98]

Mine have been whining for a year. As long as they aren't smoking too bad and hold boost, they are fine. Save up for the inevitable turbo replacement but I wouldn't worry about it meanwhile.