Stalling.

[BLZ]

I have a 2012 2.0 manual. I have managed to stall the car occasionally when setting off. It seems to start to go and then sort of hesitates and stalls. This can be overcome by making sure there are plenty of revs on when moving off. But I have to make a conscious effort to remember to do this to save embarrassment ( or a rear ender ). I have been a driving instructor for nearly 30 years and so it shouldn't happen. Any (helpful) comments ??

[flybobbie]

I Have a 23i and I notice after first start when cold that I can get a judder when setting off unless in sport mode, as though there just aren't enough revs as I slip the clutch.
It's as though the silly normal mode just doesn't provide enough revs to pull away. After that ok.
The 23i is 205hp.
I think the 2.0 is even less. Could be just the characteristic of the car, underpowered.

I also what for the fast tickover to settle down before moving off.

[R.E92]

Could be the Clutch Delay Valve (CDV). Not sure if BMW put it on all cars but it makes clutch engagement a chore. If the Z4 has it then that's most certainly the cause of your issues.

I think the CDV was only added to prevent warranty claims from the sort of dribblers who hold their car at traffic lights using the clutch. It forces people to be decisive with clutch actions.

A lot of owners have theirs removed. On my previous car the garage removed it for free during an oil change. It's not hard to DIY but if you f**k up and let air into the system you need special tools to bleed it again (or so I've heard).

[BLZ]

Yes the Z has a CDV. Its to protect the diff. I believe. It stops numpties revving hard and then dumping the clutch to get the wheels spinning.
I suppose I'll have to live with it.

[flybobbie]

Forgot to mention, I removed CDV and that reduced the judder a lot.
Simple job, just a couple of clips to remove and reconnect pipe then bleed.