An odd issue...

[GreySquirrel]

I'm having a strange issue with my 80k 2.2 M54 Z4 E85.

It seems to be a bit "kangaroo-y" (is that a word?) at low revs.

When revved, it pulls and drives absolutely as normal, BUT when I let OFF the throttle, there seems to be a slight, but noticeable surge, like a second of acceleration, before it slows down on the overrun.

At low revs, it seems a little jumpy, throttle sensitive, but maybe holding back slightly. It doesn't seem to have a misfire. I have a Creator 110 scanner, so is there anything you guys would suspect, or is there anything I could check with the scanner?

Any ideas? I've had the car for 18 months, and this is a recent occurrence, I would like to get back to the smooth engine it was before.

And yes, I have reset throttle adaptations, with no noticeable change.

 

[colb]

Suggest you clean the throttle body and idle control valve, they do get gunked up, see if that improves things. Just use spray carb cleaner and wipe the intake of the throttle body and throttle butterfly clean. Take the idle control valve out and flood that with carb cleaner to wash it out, it should rattle when you shake it in your hand then you know its clean and not sticking.

 

[GreySquirrel]

Yes, I think I'll try that. Maybe at the same time, I'll upgrade the DISA to an alloy one, and replace the CCV system as I think that may be blocked too. Probably a couple of hours of work.

Let me know if anyone has any tips or thoughts on this...

Also, should I replace the Throttle Body gasket, are the cheaper DISA rebuild kits OK, and are the many CCV kits at around the £30 mark ok, or would you go for genuine BMW?

I've had that issue with the screen rubber, and original was best in that case (and cheapest).