[jeeve.x]

Hi all, recently I noticed that there is an unusual amount of "tin-y" rattling noise on acceleration coming from the downpipe area which is amplified by my new underground parking structure and windows down. It is there on start up and acceleration but dead silent the moment I let off the throttle.

I went to a shop today to have a look at this. They put my car on the lift and after examining the downpipes and the surroundings, came to the conclusion that it was my wastegates making that noise.

Now, I thought that the typical wastegate rattle only occurs on deceleration? Is this some kind of new rattle?

The turbos were replaced last June and mods are (if they matter) JB4, DPs, FMIC, DCIs, CP and BOV. Thanks

[Pr335bob]

Did you get the turbos replaced under warranty?

[jeeve.x]

Originally Posted by Pr335bob

Did you get the turbos replaced under warranty?

No, the old rear one had a leak no rattle though.

[Pr335bob]

I had. A small rattle super small from 1.5rpm to 3. It's sounds very subtle and it just disappears. Just like yours. I have to have the windows up and no radio in order to hear it. Never checked it because I feel no lose of power yet... interested to c what caused this. I checked the turbos and nothing seems out of order.

[jwilliams]

I also have this. I have bmw warranty but they have said it is not enough rattle to warrant them. If it gets worse bring it back for reassessment.

What causes the acceleration rattle. It does not seem talked about.

[Pr335bob]

This is why I won't go to my dealer I'm out of warranty but the waste gates have 8 years 80k miles warranty aprox. But traveling an hour to get it diagnosed and hear that they are not going to cover it. And on top of that be stuck with a bill for diagnosing. Sucks.

[jeeve.x]

Looks like it's quite a common occurrence then, anyone with a solution?

[335NJ]

Originally Posted by jeeve.x

Looks like it's quite a common occurrence then, anyone with a solution?

Replace the turbos, although new OE ones will rattle again, maybe worse than before. So if paying out of pocket, VTT, and RB offer modified turbos for more output, while VTT also offer an OE replacement that has solved the wastegate rattle issue, available for much less than a "Stage 2" style kit (RB, VTT, Etc).

Mine rattle on acceleration as well, pretty annoying, but I think i'll hold out until next year for warranty replacement.

[jeeve.x]

Originally Posted by 335NJ

Replace the turbos, although new OE ones will rattle again, maybe worse than before. So if paying out of pocket, VTT, and RB offer modified turbos for more output, while VTT also offer an OE replacement that has solved the wastegate rattle issue, available for much less than a "Stage 2" style kit (RB, VTT, Etc).

Mine rattle on acceleration as well, pretty annoying, but I think i'll hold out until next year for warranty replacement.

I just replaced these last June lol. Well if I'm gonna have to replace them again I'm going single then.

[335NJ]

Originally Posted by jeeve.x

I just replaced these last June lol. Well if I'm gonna have to replace them again I'm going single then.

Did you go warranty? I'd just bring it back if you're still under warranty. A single is nice as hell, but can get pricey compared to RB, or a VTT setup from what I understand.

[jeeve.x]

Originally Posted by 335NJ

Did you go warranty? I'd just bring it back if you're still under warranty. A single is nice as hell, but can get pricey compared to RB, or a VTT setup from what I understand.

I tried to, but the previous set was leaking oil and did not rattle so the dealer would not cover it.

Yeah I know it's gonna cost a bit more, go big or go home right lol. It all depends on when can I get out of grad school and find a job.

[jwilliams]

So what causes acceleration rattle. Surely it is just a set up issue or tiny tiny vac leak or something?

[Briancanadiano]

I've had this rattle ever since I installed new oem turbos.. It could be a number of things, from a tiny vac leak, to a bad solenoid, to misadjusted wastegates. Cars boosts fine just an annoying sound, usually happens just as the car is in the beginning of boost build up, after 3-4 psi and up you don't hear it no more because the boost pressure holds the wastegate witch stops the fluttering on the wastegate seat. I've tried everything except tweaking the wastegate arm. That's the last thing you should do if none of the other solutions work.

[Tzu]

Adjust the wastegates, or if you have your tune operating from cold starts then you can alter the WGDC tables in the low load regions to mimic physically "adjusting" them.

[adventr]

Anyone got a sound clip of this wastegate rattle?

I recently installed a catless DP on my N55 car, and there is a sound at light acceleration that's a little weird. If it's a "rattle", it's pretty high frequency. Almost more of a resonance/slight rasp sound that's echoing around inside of the big hollow downpipe. It stops under heavy acceleration.

Is this what you guys are talking about by chance?

[jwilliams]

Originally Posted by Tzu

Adjust the wastegates, or if you have your tune operating from cold starts then you can alter the WGDC tables in the low load regions to mimic physically "adjusting" them.

I am very familiar with the JB4. But can you explain further what setting to put the WGDC to reduce the acceleration rattle please?

[jwilliams]

Originally Posted by adventr

Anyone got a sound clip of this wastegate rattle?

I recently installed a catless DP on my N55 car, and there is a sound at light acceleration that's a little weird. If it's a "rattle", it's pretty high frequency. Almost more of a resonance/slight rasp sound that's echoing around inside of the big hollow downpipe. It stops under heavy acceleration.

Is this what you guys are talking about by chance?

i think it is. It is so slight it sounds more like a high pitch bee in the exhaust momentarily before boost.

[Jklad]

Since it's rattling on acceleration, are you noticing any symptoms when driving? Is it building boost any slower than it should be?

[jwilliams]

Im not sure. I have had slow boost but think it was vac tanks. Since change feels better.

[Jklad]

What about part throttle, like 40-50% throttle at low rpm's - any delay or hiccups happening there?

I'm trying to see if what I feel, above, is related to rattle when initially accelerating which your describing.

[Murf]

I have this rattle also, on stock turbos. Only hear it at full throttle in 2nd gear, sounds like a rattlesnake.

Strangely I have zero rattle on decel or revving at idle. I doubt very much the dealer would replace mine as it does not occur at all at stock boost levels.

[jeeve.x]

This morning I turned off the JB4 (Map 0) and the rattle seemed to quieten down a little bit.