[Archangel621]

I know the first thing people probably think of when they see the thread title is "Not another one of these," but I think this one is a little different than the often-mentioned exhause rattle.

I've searched many times for something relating to my problem and I haven't had any luck. And from what I've read on here and seen on YouTube, this doesn't seem like it fits the description.

As you'll hear in the video below, I have this rattle (?) coming from my exhaust. It only happens after I've been driving for a while and seems to only make the sound when it's in drive...sitting at a traffic light, accelerating, etc. If I put it in park, it slowly fades away into a more normal sounding exhaust...but not always.

I've taken it to the dealer and they say they can't reproduce the problem (big surprise there). The next time I take it in, I'm going to show them this video in the hopes that someone there might have an idea since my description doesn't seemt to be enough. So for the time being, I was wondering if anyone here has experienced this or might have any idea as to what is causing it. It's been doing it for a while and I'm at the point where I can't stand listening to it anymore. Not to mention it's embarassing accelerating when around people because my car sounds like a piece of junk.

So if anyone can offer some input, I would greatly appreciate it.

[u2b]<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/8LYGGmOnGHw&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/8LYGGmOnGHw&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/u2b]

[Grendalf]

looks like your bypass valve is moving freely...

Let me know when you found out, I am curious to know.

[neverwerks]

big coincident. I am having the exact same problem. I got it checked out last week and was told that either the valve or the actuator is broken. They ordered me a new muffler (just the left side).

i was expecting a call today to confirm it was in and setup an appointment to get it installed. nothing yet

[Dan335i]

Sounds like the driver side flap rattling around. I would bet its that.

[bimmer_335]

man somthing is definitely broken there... get a new muffler.

[neverwerks]

Ok so the dealer fixed my rattle free of cost. It was the valve in the left muffler.

They replaced the left muffler by cutting the center pipe that goes from the left muffler to the right muffler and the pipe about 6-12 inches behind the left muffler.

They put the new one on with clamps between both of these new cuts. It looks exactly like the BMW performance muffler. The only diference is that I do not have a clamp behind my right muffler.

It isn't necessary but I wish they would have cut the right pipe and put a clamp on it as well. This would allow me to do a muffler delete like some have done on this bored but still be able to bolt the stock mufflers back on if need be.

[slimmie]

dang.. i have the same exact problem juyst started last week.. zzz dealership again

[Quisp]

I had this same problem and it was a faulty flap between the exhausts. The dealership replaced one of the exhausts by splicing and welding in a new one on the driver side.

[DaleT]

i had this problem in my e46 330i.. gold tee mod went and fixed the trick!