[tcw495]

I heard a weird rattling sound when I started up my car this morning, coming from the exhaust. I just had the MSport exhaust installed yesterday. It's a weird rattling type noise at idle, but goes away once the car is warmed up.

I have a video but can't figure out how to upload it.

[tcw495]

Here's the video on YouTube

[onfireX5]

Did you try opening the exhaust valves to see if it changes ? Could be the valves rattling or a clamp issue. Heat expanding metal.....stops the rattle....might be the valves.

[onfireX5]

You can also see the valves with a flashlight and look for fluttering.

[onfireX5]

After listening to your vid , I would check the torque on the Butt Butt clamps. Sounds like a pipe rattle instead of the valves rattling.

[tcw495]

Originally Posted by onfireX5

After listening to your vid , I would check the torque on the Butt Butt clamps. Sounds like a pipe rattle instead of the valves rattling.

Great, thank you!

[onfireX5]

Fixed ?

[tcw495]

Originally Posted by onfireX5

Fixed ?

Yep. The pipes were just sitting too close together and hitting each other on cold starts. Now the gap between the two is a few millimeters more, so everything has been fine the past few starts.

[onfireX5]

Good deal. I still like the Competition Exhaust upgrade.

[Robertcop666]

Hi,

Got the same problem with mine, how did you fix it?

[Justao]

Originally Posted by Robertcop666

Hi,

Got the same problem with mine, how did you fix it?

Seriously? Just read the post above🙈

[jivom5]

Originally Posted by tcw495

Yep. The pipes were just sitting too close together and hitting each other on cold starts. Now the gap between the two is a few millimeters more, so everything has been fine the past few starts.

sorry to revive an old thread, do you remember how you fixed this issue? I'm having the same problem on my m sport exhaust

[Rotary1]

I too discovered this issue on my 2019. In fact my wife mentioned it so it must be super noticeable. My noise doesn’t go away when warm but only when driving around or when the revs are higher.

Do you have a picture of how to fix this?

[Simon H]

https://f90.bimmerpost.com/forums/sh....php?t=1858472

[romanf90]

I’ve been having this issue on my 2023

Took it to bmw the tech said it was a with the rear resonator. They ordered me a new exhaust covered under warranty.

[RS61]

I've had this on my 21 Comp. Took it in a bunch of times they never fixed it, I decided to just live with it. Only audible outside, can't really hear it if I'm in the car. And it's only for the first minute on a cold start.

[justanotheruser]

Originally Posted by RS61

I've had this on my 21 Comp. Took it in a bunch of times they never fixed it, I decided to just live with it. Only audible outside, can't really hear it if I'm in the car. And it's only for the first minute on a cold start.

This morning was having the same issue when cold starting, but as you said after a minute it disapears with a 2018 m5