BMW M4 RATTLE NOISE

[mattgallf80]

Hi all,

I bought this car last week and immediately noticed a rattle noise on start up (cold). The dealer told me it was an exhaust characteristic.

https://youtube.com/shorts/102Kwc-a5k4

Above is a recording of it.

Any ideas what the rattle is? I’m tempted to take the car back under the 30 day buyers rights.

Thanks for your help!

Matt

[jm doc]

mattgallf80 said:

Hi all,

I bought this car last week and immediately noticed a rattle noise on start up (cold). The dealer told me it was an exhaust characteristic.

https://youtube.com/shorts/102Kwc-a5k4

Above is a recording of it.

Any ideas what the rattle is? I’m tempted to take the car back under the 30 day buyers rights.

Thanks for your help!

Matt

Don't have an M4 but several M5's over the years. They are all loud for the first 15-20 seconds on cold start up, doesn't sound much different from that. This your first M car?

[Superlightdaa]

Doesn't sound normal to me as an owner. I'd have a look underneath at the brackets, maybe it's a quick fix, failing that maybe something inside the silencer.

[nickfrog]

Definitely not normal on cold start up of a S55. It sounds like something is indeed loose and vibrates. It's probably exacerbated by the cold start characteristics of the engine but it's the sign of something needed attention.

[TheAngryDog]

It'll be a loose bracket, but tbh all S55's sound awful anyway.

[JMBMWM5]

mattgallf80 said:

Hi all,

I bought this car last week and immediately noticed a rattle noise on start up (cold). The dealer told me it was an exhaust characteristic.

https://youtube.com/shorts/102Kwc-a5k4

Above is a recording of it.

Any ideas what the rattle is? I’m tempted to take the car back under the 30 day buyers rights.

Thanks for your help!

Matt

That exhaust has been modified, baffle removed and welded up.

[mattgallf80]

Update:

Thanks for your replies guys. I had it in with MB LIVERPOOL BMW specialist today and they said they cannot find anything wrong.

Here is their diagnosis below:

[Admsyd]

Hi bro its definitely not normal. I just been fixed up by Sydney Bmw under warranty. They change gasket,bearing ledge,drag lever,Cam cover, bolt,O ring etc. So many things and finally noise gone.

[Kuroblack350]

mattgallf80 said:

Hi all,

I bought this car last week and immediately noticed a rattle noise on start up (cold). The dealer told me it was an exhaust characteristic.

https://youtube.com/shorts/102Kwc-a5k4

Above is a recording of it.

Any ideas what the rattle is? I’m tempted to take the car back under the 30 day buyers rights.

Thanks for your help!

Matt

Not normal in my view, if mine sounded like that I’d be taking it in Is it the Comp model with performance exhaust?

Two suggestions - one, download the M Performance Sound player on iOS - it has stock and performance tracks for the M4 and will give you a viewpoint. Two, happy to record mine if that helps..?

[Chamon_Lee]

I agree its not normal and I assume the flaps are broken in some shape or form.
Something is def off.