Z4 cranking at cold start

[JohnAle]

It is a 2012 BMW Z4 Sdrive35is. It has 57,000 miles and the car cranks/struggles at cold starts 90% of the time. Especially when sitting overnight or starting it up after work. It has no check engine light on and no codes - it seems to crank longer when cold outside. This is a new problem and it started up fine a few weeks ago.

I replaced:
Spark plugs
Coil packs
02 sensor for bank 2 (cylinders 4-6)

Here is a video of what it sounds like:
[youtube]https://youtube.com/shorts/3dZGWO0VO0k?si=DJdCXCqswAVNpHov[/youtube]

What could it possibly be?

 

[Mr Tidy]

Welcome to the forum John.

All I know about E89s I've learnt on here, but a wild guess might be the High Pressure Fuel Pump failing. Hopefully someone more knowledgeable will be able to help.

 

[Chippie]

I’ve not had the problem myself but from your description I’d say HPFP as well. Welcome to the forum

 

[raymond.harper]

The battery sounds healthy enough, give the car a few seconds for the warning lights to go out before you crank it

 

[B21]

In probability terms ..fuel injectors, high pressure fuel pump, low pressure fuel pump..

Does the LPFP run when you open the door for a few seconds..

To check the injectors pull a plug or two and see it they are wet..

HPFP needs data logging to see PSI reading..