[DBO]

Had my MPPSK for a while now, but there's some kind of snarling rattle happening at certain vibrations (cold or slowly accelerating). It sounds like a piece of sheet metal vibrating and I'm 95% sure it's one of the chrome MPerformance tips.

Anyone else with the M Performance Exhaust encounter any issues? I recall reading that someone had to spot weld their tips, but can't find the post again.

[emre]

Same here, i had it checked and yes tips need to be welded. I didn't have time for it, living with it at the moment.

It's mainly at cold start and the left side in my case.

[DBO]

Yea I think it's the left on mine as well. My guess is that the issue is the double walled metal of the tip (they have an inner and outer shell). I can feel how there's a small gap between the inner and outer on the tab which sits on the lower lip, so when it's cold they don't fully meet up and hence rattle together.

I think they must bind the two halves together by pressing that tab down at the factory to avoid the above issue. The right side on mine seems pressed in a bit more and the two parts don't have a gap. I squeezed down the left tip (on the lower edge) a bit which seems to have closed the gap and it feels a bit more solid. I'll let you know if that has solved the issue.

[DBO]

Rattle solved by doing the above.
Just slightly bend in the lower tab. No welding required.

Pretty ordinary considering how much BMW charges for the damn things.

[matty81]

I have this issue on mine since having a downpipe fitted. How do you bend the tabs on tho as there’s like a block thing behind it? So they don’t bend

[paquet]

Could the reason for the noise being only on the left on startup be because only one exhaust is 'open' on startup / below a certain rpm?

[matty81]

I always get it when pulling away or going very slow. It’s when the revs are really low. But once the car was idling and I noticed it coming from the left tip so not sure if the other one does it. It’s weird tho as it was fine before I had the DP fitted

[DBO]

Originally Posted by packet

Could the reason for the noise being only on the left on startup be because only one exhaust is 'open' on startup / below a certain rpm?

The MPE doesn't have the valve. That's only on the stock exhaust.

Originally Posted by matty81

I have this issue on mine since having a downpipe fitted. How do you bend the tabs on tho as there’s like a block thing behind it? So they don’t bend

That thing which looks like a block is only a profile in the metal, not a true block. I was able to close mine up a bit by using two blocks of wood and a clamp. Haven't rattled since. See if you can make it rattle by tapping or lightly striking it with a mallet or piece of wood before bending anything. You may locate exact spot where it's rubbing. The other thing you want to check is that the rattle is actually from the tip. When I fitted my downpipe I had trouble with another rattle but that was a clearance issue over the rear support bracket just forward of the diff. Well forward of the MPE. It's very easy to inadvertently introduce some minor twist between the downpipe connection point and the MPE, which closes the gap over that cross member.

[matty81]

I couldn’t manage to bend it but I slid a bit of folders paper in the gaps in the tabs and it’s significantly better now

[xxxjecxxx2]

Originally Posted by matty81

I have this issue on mine since having a downpipe fitted. How do you bend the tabs on tho as there’s like a block thing behind it? So they don’t bend

Same here. I was able to find one of the sources of rattle. The heat shield on the right side of downpipe.



Part #10 on this picture. Rattle was near #16. Ended up cutting part of it off.