[e92_josh]

Really weird one, thought I'd ask here whilst I wait to get it in the garage:

Driving on the motorway in a rainstorm, I hit a large puddle and planed for a bit.
Afterwards the exhaust quickly got louder and louder to the point it sounded like it must have ripped off on the water.

I pulled over to inspect and it all looked ok. Started the car again and it was quiet as normal. After another mile it suddenly got super loud, but after a further couple of miles it went quiet again haha! It stayed quiet for a further 100miles on the rest of the trip home.

Car is a 325i and when loud the tone followed engine rpm, not wheel speed.


Almost like I have a sport/screamer valve somewhere I didn't know about

Anyone experienced anything similar?
There must be a leak somewhere right?

[ChristianMoller]

Hello,
I had the same on my e46 and on my e91 325i.
Running in a puddle and sounds like formula one car, after a couple of hundred meters ,quiet.
Finaly found it, after the cat there is a joint with four bolts all of them were rusted away.
Exhaust system gets cold and get a different shape(gets shorter?) and you get a leak.

/Christian

[e92_josh]

Hey, this was spot on.
The bolted joints from mid pipes to exhaust manifold had rusted out, and the cold shock seems to have done enough to finally cause them to separate!