muffler replaced, now sound issues

[michael3435]

Hey guys, owner of a an F80 M3 with about 5k miles on it right now. I recently had to have the muffler replaced because there was a loud, high pitched rattling coming from the muffler on cold start. It would go away after a drove around for a little.

...so they replaced the muffler (the invoice says something about the silencer as well but I don't know exactly what they did, but the sales guy said they had to order a new muffler). Now on cold start its pretty quiet almost like its in efficient mode... then after a little driving opens up and gets loud again. Can anyone help me out with this? It was a pain getting the muffler replaced from the dealer in the first place because they said they didn't even notice the rattling. I don't know if its just me but before the cold start was loud and now its not loud at all?

[TahoeM3]

Originally Posted by michael3435

Hey guys, owner of a an F80 M3 with about 5k miles on it right now. I recently had to have the muffler replaced because there was a loud, high pitched rattling coming from the muffler on cold start. It would go away after a drove around for a little.

...so they replaced the muffler (the invoice says something about the silencer as well but I don't know exactly what they did, but the sales guy said they had to order a new muffler). Now on cold start its pretty quiet almost like its in efficient mode... then after a little driving opens up and gets loud again. Can anyone help me out with this? It was a pain getting the muffler replaced from the dealer in the first place because they said they didn't even notice the rattling. I don't know if its just me but before the cold start was loud and now its not loud at all?

Silencer = muffler

Maybe they didn't hang it correctly and there is something rubbing.

Edit: no explanation for why it's quieter now, either it's your perception or they did something to the new one when they put it in. It's hard to understand why they would replace a muffler for a rattle.

[michael3435]

Is it possible it could "break in"? I know as time goes on and the car gets some miles some have said the sound gets a little louder