[X3emist]

On the 28i 2013 I was standing behind ours when it was shut off and noticed a funny rattle from what sounded like just inside the exhaust tips. This has replicated every time I have listened for it. Some previous X3's had a flapper valve of some sort up inside the end of the exhaust which may be the cause.

Could any of you guys with 13 28i's see if you can replicate the issue.

[xDrive35i]

Originally Posted by X3emist

On the 28i 2013 I was standing behind ours when it was shut off and noticed a funny rattle from what sounded like just inside the exhaust tips. This has replicated every time I have listened for it. Some previous X3's had a flapper valve of some sort up inside the end of the exhaust which may be the cause.

Could any of you guys with 13 28i's see if you can replicate the issue.

That would be the flapper valve. You can disable it by unplugging the exhaust solenoid in the left side wiring compartment of your trunk.

[FX3OK]

Originally Posted by juddholland

That would be the flapper valve. You can disable it by unplugging the exhaust solenoid in the left side wiring compartment of your trunk.

The engine makes noise...you can turn it off by hitting the start/off button. Sorry had to say that.. If its normal, why mess with things. If its not, thats what the warranty is for!

[X3emist]

Interesting, I'll have to investigate further. The flapper valve has been around since at least 2006. The funny thing is, our 06 X3 doesn't have it while others have reported that they have one. I'll report back. Shutting the engine off isn't an option, don't wanna lose the fun factor of the ULTIMATE DRIVING MACHINE!!!!!!!!!!

[Beyu]

I would think it's the flapper valve also but this doesn't seem to be the case, unless they changed the exhaust system for the new 28i with the turbo inline 4. If your 28i does in fact have a valve on the exhaust you can unplug the rubber cord and this should fix it like Juddholland said.

Originally Posted by juddholland

That would be the flapper valve. You can disable it by unplugging the exhaust solenoid in the left side wiring compartment of your trunk.

The reason why one might want to unplug it would be to remove that metallic clicking sound and to make the exhausts a little louder during idle and low rpms. There's no negative consequences from doing it and it's a free way to make your exhaust louder in literally 2 minutes which Judd along with myself have both done.

Here's a pic of what the two exhaust systems look like :