Bought a used M4

[2gad]

Good morning.

Bought a used M4 from my local BMW dealer yesterday.

Two issues that don't seem right and I'd welcome comments of members before discussing with the dealership later this morning;

1. Starting from cold - a very noisy rattle from the rear box of the exhaust for 20 seconds. It sounds like an exhaust issue rather than the engine.

2. The modes for gearbox, engine, suspension and steering (Efficient / Sport and Sport+). When Sport or Sport+ is activated during driving they 'drop out' and revert to efficient.

Can they be chosen short term by just scrolling through the individual options (as per my previous car) or do they have to be saved to M1 or M2?

I appreciate I need to read the Owners Handbook however in the short term Im looking for a quick update.

Many thanks.

Graham

[Herr Schnell]

U.S thread on the cold start exhaust rattle here:

https://f80.bimmerpost.com/forums/showthread.php?t...

[s2000db]

Exhaust is completely normal...

Drive modes revert to economy when switched off, easier to configure what you want on M1, M2 buttons..

Enjoy it’s a fabulous car!!

[Pioneer]

Yep, modes should stay the same whilst the engine is on, not 'drop out'. Maybe reverts back to efficient if an issue like a limp mode? I need to read the manual too

[PorkInsider]

They are very noisy on cold start.

Drive modes can be set via the switches on the centre console or via iDrive and can be saved to M1/2 via iDrive or by just selecting what you want then holding an M button until there's a beep.

Whichever method you set them by they shouldn't reset themselves on the move though.

Unless you're pressing one of the M buttons after you've picked the modes you wanted?

[Wills2]

Check the alignment of the exhaust at the back and give it a waggle it's not uncommon for one of the brackets to break and that means a new exhaust as they are not sold separately.

Selected modes do not drop out they only reset when you switch the engine off.

[2gad]

Many thanks for the useful comments.