What's your idle speed?

[cjl_rocco88]

I know mine used to be the line before 1000rpm which is what 750 or 800 but now sometimes it sits up at 1000 all the time. It always makes me check if I've got the AC on full chant or somethin silly like that but even with everything off it sits high. It makes the gear indicator tell u to change down ear
Y and change up late as well which is weird. Not that I necessarily change when it says to but it is quite annoying when you notice it telling you to change down and you are driving along between 1500 and 2000rpm.

Any ideas? Presumably should just get it plugged in? Spent so much on it recently I'd like to avoid taking it to a garage again!

[speccy48]

Hi Cjl,

As you've got a diesel it's probably due to the car doing a re-gen at the time....................so probably nothing to worry about.

[Cuprabob]

As above, idle speed is raised during a DPF Regeneration.

For reference, idle speed is also raised if the battery voltage is detected as being low, to assist with charging.

[SPEEDDRV]

I have a 2.0 140 TDI and sometimes it sits on 1000. When you turn it off, does ventilation on the engine continues to work? If it does, it's a regen. Cold temperatures on a cold start might also raise the rpm. Mine has DSG and if it is on a downhill and start rolling while on Neutral, rpm raise too. As said, battery might also be low because Rocco know that and try to charge it. Alternator might be faulty too. Check it on VCDS.

[Cuprabob]

On the manual too, if the car is not stopped and still rolling / freewheeling the idle is held high until the car is stationary, when it then drops.

[SPEEDDRV]

Never understood why it does that. On my E Class Auto, rpm doesn't raise on a roll and if I put it in D, no big difference. But it might be related to that somehow.

[cjl_rocco88]

Thanks very much guys! Yeah I forgot to say as well that it only does it sometimes, too so the dpf thing makes complete sense. as I have been doing a lot of short journeys recently whereas in the coming up to three years I've had the car I've never noticed it doing it unless it was cold or like I mentioned putting the battery under some strain with the AC on.
Nothing to worry about (sigh of relief)
Starting to love my car again!