M275 "whoooo" noise on throttle stab

[pillow]

Hi everyone,

This may be totally normal but in the last few months I have noticed a "whooooo" noise when stabbing at the throttle pedal that I don't think was there before.

Only really happens with a quick press and release of the throttle while in gear. Is this normal?

I hope to get a recording of the sound if there are no obvious answers.

Thanks

 

[John]

I've heard diesels making that noise with the exhaust tinkered - it sounds like the turbo spinning down through the exhaust.

Wonder if it's a similar thing as you have pair of turbos in the CL600.

 

[Bobby Dazzler]

Hi everyone,

This may be totally normal but in the last few months I have noticed a "whooooo" noise when stabbing at the throttle pedal that I don't think was there before.

Only really happens with a quick press and release of the throttle while in gear. Is this normal?

I hope to get a recording of the sound if there are no obvious answers.

Thanks

Does it make the noise as you’re lifting your foot? Is the car turbocharged? If so then I suspect you can hear the boost pressure being released. Many years ago we had an ML270 CDi (diesel) which made a “mewwww” noise for this reason.

 

[John]

Does it make the noise as you’re lifting your foot? Is the car turbocharged? If so then I suspect you can hear the boost pressure being released. Many years ago we had an ML270 CDi (diesel) which made a “mewwww” noise for this reason.

I think it's the same noise we are hearing.

I'm pretty sure all 216 600s are turbocharged.

 

[pillow]

Ok, last night and this morning I went out to try and replicate the noise and I can't get it to do it any more which to me suggests that the specific noise I'm trying to describe is not normal.

You are right all 216 600s are turbocharged but the turbo sounds are very quiet on this engine.

If I can catch it making the noise again I'll try to record it so people can offer suggestions as to what it might be.