06 M45 exhaust rattle - any updates

[ArbitrageMan]

In reference to this post regarding exhaust rattle on M45s during light acceleration:zerothread?id=220421

Im taking my car in this week, and it'll be the second time Im bringing up this issue. Im going to take the service manager for a ride in the car so he can hear the noise. If my wife can hear the noise from inside with the windows up, this guy definitely should be able to.

But I wanted to know if anyone has any new experiences in getting this issue fixed on their car? Any magic words I ought to say? Any service bulletins? Thanks.

[SteveTheTech]

Sorry I did not see the other thread, and will read it but I want to give my quick thought on your concern.

I had one today with this exact same concern. It was a 24k 06M45 Sport. Upon inspection I found there was a sufficient amount of oil but the filter did not have the internal dampening valve that the OE filter has. Sometimes increased engine bay temperature can cause that noise as well as questionable fuel quality are the leading causes but there are many things that often get overlooked. The VK has a very simple design and the operation is very straight forward. Many SAs and Techs chalk this noise up to fuel and call it a day.

I wish you the best of luck, please keep us informed.

Now I am going to read that thread I just wanted to reply while the initial thought was still in my head.

[Jayvon2k4]

Hello all. New to the site but I've had this issue with my M. After taking a look at the exhaust I found out that one of the chrome tips had became loose. The dealership told me it would cost about $200-350 to replace since its a one piece deal. But I took it to a local exhaust shop and they welded the tip for $25. Hey it worked for me...

[New2Import]

It may be emergency brake also. I had a bad rattle when I got on rough roads or hit bumps. Its a 10MM bolt at the pedal that you tighten and thats the fix.

[NJ 666]

I've seen a handful do this usually when it shifts 1-2 or 2-3. Haven't been able to come up with a solid fix. We replaced the right rear res/muffler on one and it didn't come back....yet. But it sounds like you might have a different issue.

[ArbitrageMan]

Yeah, thanks for the replies, but the noise is none of the above.

Its a loud, metallic fluttering noise, from the exhaust, during light-medium acceleration between 2300 and 2800 rpms. Usually 2nd or 3rd gear.

Someone on the previous thread posted the cause as micro fractures of the y-pipe, and that sounded like the most probable cause.

[SteveTheTech]

Sounds like a good one, and chance to resolve a long lasting frustration.

Where are you taking it?

[leftlane1]

I bet you bottom dollar it is the Y pipe. You are describing the exact sounds I was having, and I b****ed about it long enough and loud enough that it got fixed. That Y pipe hangs too low - in my opinion, a design flaw - and it's not extraordinary to have it hit speed bumps or high points. I almost guarantee that if your service tech gets under there and power brakes the car, they'll find the cracks. Replace the pipe, and I bet your problems are fixed. Push them hard - it doesn't always duplicate for them, but don't take no for an answer.

Here's the other post:

zerothread/220421