B58 cold start exhaust even when engine hot

[Chestrockwell]

My M240i has MPE exhaust and nothing else

I understand a cold start, cars have their ways of heating up, I don’t understand the mechanics of it but It seems fair.

After nearly 3 years of ownership, I’ve reached my limit. Why does it start up like that even when the engine is hot, I’ve heard other B58’s start up in 540i’s and X5’s and they don’t sound like that, yes I have the MPE exhaust, and again, I understand an actual cold start but not one when I’ve been driving for hours.

It’s not the biggest problem in the world but for example if I need to pick something up from a friends house at night who live in a cul de sac, I have to leave the car running just to avoid starting it up again and disturbing others because it is loud.

Anyone else have this problem?

[Tupper76]

I used to own a BMW M340i and I had an AWE exhaust (no valve, no muffler) so it was clearly louder than yours.

Warm starts were quick and crisp, I don't think they were all that loud or disruptive.

I found that the best way to keep the volume down in residential areas was just to drive slow, ie keep the RPMs low

[MarkJS]

All B58’s do this in my experience - it might be a little less noticeable on OPF cars as they are quieter anyway. A little pressure on the throttle with a bit of practice lowers the revs and reduces the noise.

[culpz]

No direct experience personally, but I'm sure this is why many people have the cold start deleted on these, so sounds normal. My dad had an M240i for a while and I can't remember if that did it or not. As someone said above, it might be something to do with if it has a GPF or not.

[b14]

My B58 has a GPF and it's still v loud on cold start. If you start it with the tiniest bit of throttle it'll start and idle slightly higher than base idle and then the wastegate is closed and it sounds like normal without the roar.

[c3m]

[redacted]