Violent shaking on idle (not occasional wobble)

[AJP]

This morning starting it from cold the engine was really shaky on idle, then seemed to settle down as the revs settled to 800ish rpm.

Just to note, this isn't the occasional hiccup/wobble at idle every ten seconds or so (that I've always experienced with a hot engine), more a constant shaking like it's missing with every turn of the crank.

Drives fine under load, in gear etc.

My first thought was pcv, although it had a new one less than a year ago.

Any thoughts?

[Andy]

Coil pack

[AJP]

Coil pack

I always thought a dodgy coil would be more apparent as a misfire at higher revs?

[Nasir]

Coil pack

I always thought a dodgy coil would be more apparent as a misfire at higher revs?

Can happen at the low end. Sounds like it is a coil pack. Remove each one individually, if it gets worse, it's not that one, if it stays the same then you have your answer.

[AJP]

Weird that once the revs drop to the usual 800rpm it's smooth - and if I then hold the revs at the same 1200ish rpm to replicate the initial warm-up revs it's also smooth.

[pudding]

If it's not a complete spark cut from a dodgy coil or worn out plug, and not an injector nozzle issue / lazy injector...... then as a guess, could it be carbon build up preventing the intake valve(s) from closing fully?   Quite common as these engines get older.  As the engine warms up, the carbon softens and the valves seal up again.  Other rpms might smooth it out also.

[AJP]

If it's not a complete spark cut from a dodgy coil or worn out plug, and not an injector nozzle issue / lazy injector...... then as a guess, could it be carbon build up preventing the intake valve(s) from closing fully?   Quite common as these engines get older.  As the engine warms up, the carbon softens and the valves seal up again.  Other rpms might smooth it out also.

Yeah, it's always done the occasional wobble thing, only when warm, which I put down to carbon buildup like you say.

It's going in for a major soon anyway so it'll be getting new plugs at the very least. I'll keep an eye on it. Might just need a new coilpack.

[Ricky123]

Have you scanned it to see if there's any fault codes?

With you saying it's always had the occasional wobble I'd say have a look at the injectors, quite common for an injector to cause a mild idle issue on these engines.

[AJP]

Have you scanned it to see if there's any fault codes?

With you saying it's always had the occasional wobble I'd say have a look at the injectors, quite common for an injector to cause a mild idle issue on these engines.

It's in at Statller at the start of April for the clutch so I'm going to ask Steve to scan it while it's there. Kind of hoping it throws something up that explains it, save me scratching my head!

[pudding]

Have you not got VCDS?   Pretty much invaluable for any post 2001 VW!

[AJP]

Have you not got VCDS?   Pretty much invaluable for any post 2001 VW!

Not yet! It's on the ever-expanding list of jobs..

[Nasir]

You said you're going to Statllers so you must be close to Sheffield? If you fancy a drive to Leeds I'll give it a scan for you.

[AJP]

Cheers mate, that's very good of you. I'm just south east of Sheff. Leeds is 50 miles and pretty much bang on an hour for me. I'm quite busy for the next few weeks so probably not much of a chance to get up, but I'll bear it in mind for the future.

Also going to head up and see Pashka at some point to sort out my tunes, but that's a long long way off!

[Nasir]

No worries mate. My car is in at Statllers at the moment, hopefully having the steering angle sensor fault fixed.

It wouldn't take more than 20 minutes to get down to Sheffield on the M1 if they didn't have constant 50 zones and "smart motorways". I'm led to believe the cameras stay on, so anything over 75ish is risky. So you end up just looking at the speedo and not the road.

[r5gtt]

All that knowledge AJP and you haven't even got a vagcom lead ffs man where's your cable at  get yourself a cable as this is a must for all vag owners 

Gosh we have to spell it out for you