135 Engine Whistle/Whine

[chupatribra]

A few months ago, I noticed a subtle whistle/whine sound from my 135 engine. It occurs typically in lower RPMs (2k-3k) when accelerating. I know this is a little silly, but it sounds almost like a nose-whistle - like when you're breathing and your nose is a little stopped up. It's not very loud. In fact, I couldn't even get a serviceman to notice it because the road/traffic noise covered it.

I don't know if it has been there all along, because when I first picked up the car last summer, I had the top down all the time. Even if the top was up (rain), I had the audio on or there was enough noise from the rain/road/traffic. It seems that I began noticing the sound about the time I began driving with the top up due to cooler weather, sometimes without audio.

I'm posting this because I want to know if anyone else notices it in their car. I never noticed this in my 330 or earlier cars. Does it result from the turbos? Should I be worried about it?

[parky1215]

I do hear minor whistle/whine noise on my brand new 11 135i coupe.
It is noise from turbo spooling up.

I like hearing that noise. In fact, I am soon going to have air filter and downpipe replaced to make that noise louder :P

[1SerieStud]

It's called turbo spool up.

[Brandon26pdx]

Originally Posted by maxnix

I guess I am deaf. I hear whirring noises, but no high pitched whine.

turn the radio off and dip into the accelerator in 2nd gear at about 2k rpms. you'll hear it coming through the vents

[MarkR171]

Originally Posted by Brandon26pdx

turn the radio off and dip into the accelerator in 2nd gear at about 2k rpms. you'll hear it coming through the vents

With the windows up, AC off and no other cars around you will hear the high pitch whine through the vents. It's very subtle, but it's there.

[1on135_deal]

this how you can get it do it on command accelarate slowly in like 2 nd 3 gear u will hear it spooling up around 2k to 3k rpm pretty cool i think also since i did my exhaust i can hear it more now i dont know if it has to do with less back pressure deff need to dyno the sob!

[Ihave1]

I heard this same thing. Sounds like a dentist drill or police siren in the far distance. I googled it and was sure my turbos were about to die. Today I went to an indy import place and they said its normal turbo spool up, which is what I hoped was the case. Its hard to hear with any outside noise and happens right between 2 and 3k rpm. Seems to actually be louder in the car (maybe due to sound generator p/n 13717575658?) since the engine is so loud and drowns out the sound if you pop the hood.

[bluesunit]

My car ate a power steering pump.

They symptoms were a whine at <3000 RPM, which would be then be covered by engine noise. Sounded more like a supercharger than a turbo.

Just one thing to consider.

[SoCali E36]

Originally Posted by bluesunit

My car ate a power steering pump.

They symptoms were a whine at <3000 RPM, which would be then be covered by engine noise. Sounded more like a supercharger than a turbo.

Just one thing to consider.

my friend had the same exact issue. they replaced the pump and the noise went away

[Ihave1]

Ah, good to know. I would still take that over a turbo going bad any day.

[MrBlonde]

That's the sound of the turbos.