Kazoo/Duck Quack Sound on Acceleration

[Davey27]

Hey everyone,

Would really appreciate picking the collective brains of this great forum, and getting some insight and thoughts on a very strange noise I am hearing, which appeared this past Friday (5/22), upon getting my M3 back from the mechanic (also planning on calling them when they open back up after the Memorial Day Weekend, but hoping to gather initial impressions here first).

It occurs almost instantly upon medium acceleration at around ~2k - 3k RPM, but does not occur every time, I would say 25% of the time it will make the noise. Best examples I can give is that it sounds like a duck quack, a squeak, and/or kazoo, coming from the front of the vehicle for less than a second (hard to pinpoint exactly where while underway). As I said, this began after picking up my car from the shop, where they replaced the secondary emission control air pump, the front fender liners on both sides (parts #51-71-7-899-815/51-71-7-899-816, and #51-71-8-044-649/51-71-8-044-650), as well as swapped out summer wheels and tires (359s - Michelin pilot super sport).

Best answer I have right now is that the replacement secondary air pump is faulty, and causing the noise. Just now sure if this is problematic, or another typical quirk noise of our cars. It wasn't there before they replaced it...

No mods on the car, everything is stock.

Anyways...sorry for the long-winded background, attaching a couple sound clips of the noise. If you listen closely, you can hear it at the 4 second mark of both clips.

[Peertwelve]

Originally Posted by Davey27

Hey everyone,

Would really appreciate picking the collective brains of this great forum, and getting some insight and thoughts on a very strange noise I am hearing, which appeared this past Friday (5/22), upon getting my M3 back from the mechanic (also planning on calling them when they open back up after the Memorial Day Weekend, but hoping to gather initial impressions here first).

It occurs almost instantly upon medium acceleration at around ~2k - 3k RPM, but does not occur every time, I would say 25% of the time it will make the noise. Best examples I can give is that it sounds like a duck quack, a squeak, and/or kazoo, coming from the front of the vehicle for less than a second (hard to pinpoint exactly where while underway). As I said, this began after picking up my car from the shop, where they replaced the secondary emission control air pump, the front fender liners on both sides (parts #51-71-7-899-815/51-71-7-899-816, and #51-71-8-044-649/51-71-8-044-650), as well as swapped out summer wheels and tires (359s - Michelin pilot super sport).

Best answer I have right now is that the replacement secondary air pump is faulty, and causing the noise. Just now sure if this is problematic, or another typical quirk noise of our cars. It wasn't there before they replaced it...

No mods on the car, everything is stock.

Anyways...sorry for the long-winded background, attaching a couple sound clips of the noise. If you listen closely, you can hear it at the 4 second mark of both clips.

This is just a guess.... was the plenum off? I recently read a member described a whistle/whine/supercharger like noise on partial throttle. It was a worn intake plenum rubber seal. He fixed it with liquid gasket. I can try to dig up the thread if that helps. Good luck!

[Davey27]

Originally Posted by Peertwelve

This is just a guess.... was the plenum off? I recently read a member described a whistle/whine/supercharger like noise on partial throttle. It was a worn intake plenum rubber seal. He fixed it with liquid gasket. I can try to dig up the thread if that helps. Good luck!

Thanks for the thoughts! I saw that thread recently as well, but I don't think this sounds similar to that noise. Especially since it comes only for a brief second at around 2k RPM, and goes away any higher in the rev range.

Just brought it to my mechanic today and they were stumped. Put it on the lift and gave it throttle, heard the noise but unable to pinpoint it. Their best guess was that it could be the result of poor gas, as my most recent fill up 1-2 weeks ago came from an unbranded corner store gas station (albeit with 93 octane - I was in a bind and unfortunately had no other choice).

[Richbot]

bad gas...lol