2.0 tfsi erratic idle...

[yorksphil]

solved first problem, now enjoying the next one! not...

looking for a bit more advice on a 2.0 tfsi...
Been sat on motorway for a couple of hours, get off it and up to a set of lights and stop, and car is ticking over a bit rough, then revs up to 2000 rpm and drops back down to 800 ish...rpm, then a few seconds later does it again maybe 1600 rpm this time, and drops back again....
left it for an hour and drove again, exactly the same thing happens on tickover, drives fine but occasionaly on throttle lift felt a bit harsh , as though fuel or spark had been cut for an instant...

Any ideas what i should be looking at, ( Pcv, dv, or vacuum leak spring to mind) can't seem to find a definitive thread/ or similar on here....
Thanks in advance folks....
Phil.

 

[MrLapou]

vac leak.
Take oil cap off to see if engine runs rougher.

 

[S3AMK20VT]

sounds like coilpack, common faults

 

[s3_sid]

sorry to jump in but when i remove my oil filler it runs very rough !! almost wants to stall is that a vac leak ?

 

[Ads]

Pcv

 

[pinterovski]

Check for any other leaks but i'm sure that PCV is broken!

 

[MrLapou]

no vac leak..

cap removal simulates a vac leak, so engine's running fine

sorry to jump in but when i remove my oil filler it runs very rough !! almost wants to stall is that a vac leak ?

 

[prt57]

Hi,
I had this happen on our GTI 1.8T a couple of years ago and VW fixed it by cleaning out the throttle body, Been fine since.

 

[Artimus]

I had something similar on a previous car (although not a VAG) that had spent a couple of months sitting in traffic without a decent run out! fixed it by disconnecting the battery, then pulling the ecu fuse to reset the learned driving style and all was well again.

 

[yorksphil]

Cheers for the replies folks,
can't get oil cap off, definately being held by suction....
going to look for problems tomorrow, weather permitting....

thanks again, Phil.

 

[Dan_Mol]

Cheers for the replies folks,
can't get oil cap off, definately being held by suction....
going to look for problems tomorrow, weather permitting....

thanks again, Phil.

If suction behind oil cap, its PCV valve.

06F 129 101 N - Valve - £32
06F 103 483 E - Gasket - £16

Could probably get away without gasket, easy DIY fix under airbox 4 Allen key bolts and its off.

 

[yorksphil]

Thanks folks,
new pcv and gasket fitted today.... tickover is now smooth,
and turbo seems smoother and pulls harder...
Or is it me imagining it?....

thanks for the advice.... Phil

 

[Dan_Mol]

No mine ran a lot better with both parts replaced.

 

[kimhemm]

Thanks folks,
new pcv and gasket fitted today.... tickover is now smooth,
and turbo seems smoother and pulls harder...
Or is it me imagining it?....

thanks for the advice.... Phil

Not your imagination for sure. The old OEM PCV have been leaking for some time stealing your boost