[Lashko]

I’ve been getting this rattle when I start the car. Also rattles under light acceleration.

Video Link with noise :

[jeddo45]

It sounds like it's coming from the front of your engine. If I'm right, you have waste gate rattle. You'll need to adjust it or swap out the turbos in all.

Search up waste gate rattle. You'll get a lot of hits.

[Lashko]

Originally Posted by jeddo45

It sounds like it's coming from the front of your engine. If I'm right, you have waste gate rattle. You'll need to adjust it or swap out the turbos in all.

Search up waste gate rattle. You'll get a lot of hits.

Doesn’t seem like wastegates. Could it be downpipes? Maybe a gasket there or a bolt loose

[86merc]

I just installed VRSF downpipes on my 2009 E90 335xi. It seems to make the same noise. We threw it back up on the lift and didn't find any leaks or loose hardware. We took our fists and hit the stock exhaust. It rattled. We took a rubber hammer and hit the exhaust and it rattled the whole exhaust. We were very surprised as it didn't make any noise with the stock exhaust.

I think the combination of the downpipes are not tied together and attached to the chassis mount like the originals. As well as no flex joint on the downpipes to help isolate engine movement and vibrations.

[Lashko]

Originally Posted by kens

http://www.e90post.com/forums/showthread.php?t=80661

Try that and report back.

wastegate rattle is undeniable sound/symptom: when you sit in park/neutral and rev to 4k real quick then let go of the throttle, it'll rattle immediately after letting off while it goes back to idle.


If you don't notice that, then it's probably the exhaust flap, fix in the above link.

Doesn’t make that instant rattle when I rev to 4K. And there is no rattle coming from the back so it’s not the exhaust flap. I did a cold start this morning and I tried to find an exact location where the noise is coming from. It’s coming from the passenger front wheel. Could be the wastegates after all, but yet again it doesn’t make that instant rattle no matter what rpm I rev it to.

Edit: I’ve also tried to play around with the vacuum hoses. Did the cold start and unplugged the vacuum hoses and I still get that damn annoying rattle.

[The_E92_Fan]

your pipes might be touching the subframe. Mine were, i just had to loosen the V-band and rotate them away from the frame.

[jeddo45]

Originally Posted by PizDun2017

Doesn’t make that instant rattle when I rev to 4K. And there is no rattle coming from the back so it’s not the exhaust flap. I did a cold start this morning and I tried to find an exact location where the noise is coming from. It’s coming from the passenger front wheel. Could be the wastegates after all, but yet again it doesn’t make that instant rattle no matter what rpm I rev it to.

Edit: I’ve also tried to play around with the vacuum hoses. Did the cold start and unplugged the vacuum hoses and I still get that damn annoying rattle.

If you rev your engine up to boost, and let it off, you will hear if it is wastegate because it will coincide with the let off. You need to rev it high enough where the wastegates will actuate.

If your saying that you have already revved it and there is no rattle when the engine comes to a rest, it might not be wastegate rattle.

I say you get the car on some kind of lift, pull out your plastic barriers and start the car and see if you could isolate the sound.

I'll ask a simple question, did you recently install downpipes? If so, was it making this noise before? There's a chance like someone else mentioned that something may not be secured down properly. Your best bet is to get the car high enough where you could safely get under while the car is on to see if you could isolate the noise.

[Lashko]

Originally Posted by jeddo45

If you rev your engine up to boost, and let it off, you will hear if it is wastegate because it will coincide with the let off. You need to rev it high enough where the wastegates will actuate.

If your saying that you have already revved it and there is no rattle when the engine comes to a rest, it might not be wastegate rattle.

I say you get the car on some kind of lift, pull out your plastic barriers and start the car and see if you could isolate the sound.

I'll ask a simple question, did you recently install downpipes? If so, was it making this noise before? There's a chance like someone else mentioned that something may not be secured down properly. Your best bet is to get the car high enough where you could safely get under while the car is on to see if you could isolate the noise.

I’ll lift the car up on ramps to try to isolate the noise. Everything on the car is stock except for the rear mufflers. Thank you for the advice though. I’ll check back soon with my results.

[Lashko]

Originally Posted by The_E90_Fan

your pipes might be touching the subframe. Mine were, i just had to loosen the V-band and rotate them away from the frame.

I’ll give it a try. How difficult was it to loosen the clamp?

[The_E92_Fan]

It wasn't hard at all. Get an extension and slap on a deep 10 mil and you don't need to take anything off.