exhaust clapping noise

[piratefanlyle]

there is an exhaust clapping noise from the left tail pipe when starting on cold mornings...what is the est fix for this?

patient: 2002 330i w/ 146k

lyle

[EdirtySicks]

There is a valve back there on the e36 328s that opens at 3k rpm IIRC.

But I have no idea on a e46.

try here:
http://forums.bimmerforums.com/forum/forumdisplay.php?f=15

[groomerss]

Yes EdirtySicks is right. There is a diaphram and valve back there in the muffler that uses engine vacuum to open and close the valve depending on engine load. That diaphram can go bad and cause that valve not to stay open or close causing it to rattle. Also check the vacuum line to the diaphram.

Worst case senario would probably have to replace the muffler.

[EdirtySicks]

Replace muffler? Just remove the damn valve lol

[groomerss]

wish is was that easy. Its part of the muffler man :/

[jesse096]

Pull the vaccum line and plug it, problem solved.

[groomerss]

fix it right the first time lol jk