[AbuAdderall]

Hello everyone,

This is my second post so please be patient with me lol. I've done some research before about exhaust rattling, but none of the prior threads have answered my question.

I got my car last month, and it had the AWE touring exhaust installed by the previous owner.

So I was stuck in bumper-to-bumper traffic and this is when I noticed the sound the most and was able to identify it quite specifically.

No matter what gear I'm in, I notice a very jarring rattling sound from the exhaust area at ~700-750 RPM, and it goes away as the engine approaches 1000 RPM. Then, when remaining in that same gear, it comes back around ~1300-1350 RPM and also goes away. I pinpointed these two specific rev ranges while being stuck in traffic. Sometimes the rattling is so pronounced that it causes the shifter to shake a bit (though I'm not sure this is the same rattling, since the shifter doesn't shake all the time).

Otherwise, I only occasionally notice this same rattle upon startup, (as mentioned in other threads by posters with the same problem), but my startup rattling wasn't consistent enough for me to really make note of how/when it happens. Though it doesn't happen as consistently, the startup rattle is the exact same as the one I've mentioned above.

I haven't had the time to take it to a mechanic with my busy schedule, but that's what I intend to do anyway. I just wanted to make a post on here to get some ideas before I end up showing it to the guy.

Thanks for reading and responding! Hoping this is a simple fix lol.

[F22heidrun]

A while ago my exhaust had a major rattle issue coming from the exhaust, sounded like a coke can with a coin inside violently shaking.
This was due to a broken exhaust valve clip (that metal thing that connects the valve motor to the exhaust flap). I would assume that this is not the problem.
The other thing that rattles is the waste-gate, this is more or less a common issue and will become more pronounced with a downpipe or different exhaust.
The waste-gate rattle will go away at higher rpm's and will rattle at low rpm's.

[TheClaw]

I also have an AWE touring exhaust with the same issue, although it's not really that bad. Check to see if the exhaust tips are pressing against the body of the car, and if not it's probably something relating to the way it was installed, which is the problem in my case. Since the cabin in the m235i is very quiet, it doesn't bother me enough to fix it, but if your tips are against the rear bumper that may be the problem.