Wastegate rattling noise between 1500 - 1700 rpm

[parky1215]

I started noticing wastegate rattling noise between 1500 - 1700 rpm after I installed non-resonated Remus midpipe to ZCP muffler/stock downpipe.

Here is video clip of my car showing the noise issue.

I usually notice it during slow acceleration. As soon as my rpm needle goes into those rpm range, I start to hear buzzing/rattling noise and goes away once rpm climbs beyond 1700 rpm.
I sometimes hear noise around 800 rpm in 1st gear, but this is less annoying than one that happens around 1500 rpm.

The noise only seems to happen when engine is warmed up.
Rattling noise does not come until I drive the car for few minutes.
Also, I cannot reproduce the noise when engine is not under load (eg. standstill revving).

Midpipe seems to be well installed with plenty of clearance everywhere.

Searching on the forum shows that the problem could be either turbo wastegate or exhaust valve flap.
I don't think it is exhaust valve flap as I hear noise more toward front of the car. Also exhaust valve flap rattle sounds bit different than this noise.

I have BM3 but I don't think it is tune issue since I tried several different available tunes on my profile such as stage 1, CS, GTS, CS+, and even stock tune.

It is little bit embarrassing to slowly drive around the town with this rattling noise. Otherwise, Remus midpipe really wakens up exhaust note on my car!

[parky1215]

Uploaded new video showing the issue.
I am going to jack up the car this weekend to see if I can discover anything on wastegate.

[mitch32]

You ever pinpoint issue?

[parky1215]

Originally Posted by mitch32

You ever pinpoint issue?

I tried to remove some plays on external wastegate arm using some stainless steel aircraft wire, but it did not do anything. So I came to conclusion that the noise is coming from internal wastegate flap rattling inside turbo.

[CeglA]

I have exactly the same problem in the same conditions. Only when car in warm, during slow acceleration. Its so annoying. My exhaust is 100% stock.

Did anybody found solution?

Regards!
Chris

[jballer123]

I have the exact same noise , stock zcp package

[papasmurf_m3]

I notice the same only at very low rpm all stock with mpe optioned from the factory.

I heard that the valvetronic valve in the rear section of the exhaust can make noise too. Something about removing some washers to put more tension on the arm and eliminate vibration?

Can anyone confirm.

[parky1215]

Just an update. My M3 in the video is 2015 model with 60k miles.
My girlfriend has 2017 M4 with less than 3k miles on it. I started to notice same sound (albeit quieter) coming out from her vehicle.
Her car is Competition car with everything stock.
So it looks like this noise is something that gets progressively worse as you accumulate more miles on turbo.

[papasmurf_m3]

Never heard this vibration coming from engine bay. Just the exhaust area during cold start and low rpm for brief second. Guess that is a different noise lol.

[CeglA]

Originally Posted by parky1215

Just an update. My M3 in the video is 2015 model with 60k miles.
My girlfriend has 2017 M4 with less than 3k miles on it. I started to notice same sound (albeit quieter) coming out from her vehicle.
Her car is Competition car with everything stock.
So it looks like this noise is something that gets progressively worse as you accumulate more miles on turbo.

Do you hear this sound inside or with windows down?

I installed new ZCP exhaust and my old catalytic converters ( I had downpipe for some time ) and I hear it very cleary now but only with windows down. My car in non ZCP. Maybe its something with ZCP exhaust?
During slow speed in the city everyone around can hear this sound... Its quite embarrassing... :/

Thanks for the update

[parky1215]

Originally Posted by CeglA

Do you hear this sound inside or with windows down?

I installed new ZCP exhaust and my old catalytic converters ( I had downpipe for some time ) and I hear it very cleary now but only with windows down. My car in non ZCP. Maybe its something with ZCP exhaust?
During slow speed in the city everyone around can hear this sound... Its quite embarrassing... :/

Thanks for the update

On low mileage M4, I only hear with Windows down.

On my high mileage M3, I hear it both with windows up and down.
Obviously, I hear much less on M3 with windows up, but it's loud enough that I still hear rattling noise with windows up.

[mjrmatt]

happens on mine too, exactly the same... I think its normal?

[PandaxF82]

Any updates on this?

[fanofbmwe46]

Any updates on this? Interested to hear what the fix is

[jasonjo]

[fanofbmwe46]

Originally Posted by jasonjo

Interesting. Anyone know the part number?

[Shubacca]

Originally Posted by parky1215

On low mileage M4, I only hear with Windows down.

On my high mileage M3, I hear it both with windows up and down.
Obviously, I hear much less on M3 with windows up, but it's loud enough that I still hear rattling noise with windows up.

Did you resolve your rattle?

[chrison600]

Originally Posted by fanofbmwe46

Interesting. Anyone know the part number?

I'm also interested in finding this part and/or the TSB. The "shims" in the Emerald video look like run of the mill E-clips to me, but I'd buy the official BMW versions anyway.

Anyone?

[Shubacca]

Originally Posted by chrison600

I'm also interested in finding this part and/or the TSB. The "shims" in the Emerald video look like run of the mill E-clips to me, but I'd buy the official BMW versions anyway.

Anyone?

My plan is to buy this assorted e-clip pack and try till one fits. My hunch is it's a 12-15mm but not sure. I'll be away for 2 weeks but am going to give it a try second week of sept.

Hilitchi 328-Pcs [10-Size] Alloy Steel E-Clip Circlip External Retaining Ring Assortment Set https://www.amazon.com/dp/B079BK3X26...UTF8&psc=1

[chrison600]

Originally Posted by Shubacca

My plan is to buy this assorted e-clip pack and try till one fits.

Do you know if the clip is installed on the shaft into the turbo housing, or is it installed on the linkage (on the connection to the flap actuator arm?)?

I'm wondering if the repair is intended to take away play in the actual shaft/housing interface, or if this is a rattle on the linkage between the actuator(s) and the flap arm.

Chris

[Shubacca]

Originally Posted by chrison600

Do you know if the clip is installed on the shaft into the turbo housing, or is it installed on the linkage (on the connection to the flap actuator arm?)?

I'm wondering if the repair is intended to take away play in the actual shaft/housing interface, or if this is a rattle on the linkage between the actuator(s) and the flap arm.

Chris

The fix done in the video above was taking out play in the arm. Honestly not confident this is gonna work. I might be completely wrong, but I think the vibration of the S55 at ~1500 RPM coincident with the wastegates closing is gonna cause this rattle regardless of where I stick shims. I'm still gonna try it.

[chrison600]

Originally Posted by Shubacca

The fix done in the video above was taking out play in the arm. Honestly not confident this is gonna work.

I spoke with an old friend today who is a BMW master tech (still active). He could not find an official TSB in this regard. He wondered if the repair was an attempt to take out slop where the valve shaft had worn the turbo housing. He is aware of fixes where the turbos are removed and bored out for new shaft bushings. I was wondering if you thought or knew if this was a shaft/housing interface issue, or an actuator linkage issue.

I may dig around on the turbos myself to see if I can find or narrow the source of the vibration.