Hello all. After a couple of very happy error free months of driving since I picked up my VRS in October, I seem to have picked up my first issue.

 

After returning from work tonight I had to go out to run an errand, jumped back in the car having been inside for around an hour, and instantly noticed that in neutral after turning on the ignition the idle speed was going up and down without any throttle being applied. 

 

It seems to jump from around 800 rpm up to about 1500 and then drop down and repeats in a non uniform pattern.

 

When I drove it there was nothing else wrong with the car and when in gear there didn't seem to be any fluctuation of revs either on or off the throttle, however, as soon as I came up to junctions or roundabouts and had to dip the clutch or put the car in neutral the revs instantly flared up and down again....but no higher than 1500rpm each time.

 

There seems to be no other issues with the car, the engine is smooth in gear and under throttle, no loss of economy, doesn't sound rough etc.

 

Is  it something simple like a sticky accelerator pedal or does anyone have any other ideas/experiences with the same thing.

 

Al help much appreciated as always.

Sounds like it could be an issue with the PCV or one of the hoses connected to it - there are lots of threads about it. This one is particularly good:

 

http://www.mk5golfgti.co.uk/forum/index.php?topic=44709.0

 

it's for the VW Golf GTI, but the engine is the same as the VRS.

Thanks for that, very helpful.

 

On cold start up this morning the issue had gone, but as soon as I'd done a 15 min run and reached work the issue was back so it's definitely not just a 'glitch'.

 

I'll explore the PCV side of things to see if that's the problem.

 

Throttle body needs cleaning would be my guess.

Idle speed too low/high:

Had the exact same issue with mine last year, Replaced the PCV and worked a treat!