Occasionaly my vrs idle drops 100 rpm ish and goes lumpy and judders the car? I can't seem to cause it just happens. I have had 3 out 4 coil packs changed if that makes any odds and I do have a boost issue which is resolved by ignition on off (annoying)

Any ideas or known issues? Is it or can it be serious?

Thanks in advance

Start with the easy stuff first with a throttle body clean then you are looking for vac and boost leaks?

May also be the secondary air pump

Edited 24 March, 201214 yr by karlbar2k

It is also intermittently rough when cold until that secondary thing shuts off but this idle issue has only occurred when it's already warmed up. I'm probably looking at a bunch of faults overall but I'll start with idle first. Ps only done 56k so is throttle body clean necessary ?

am intereastred in this as my brother has started the same since i did all the breathers. there are no leaks i can find. am going to have a look at the throttle body tomorrow as my mate has had the same issue with his like.

Yeah they can need cleaning at that mileage, I've done one or two around 50 or 60k which weren't too bad but they still had coking around the throttle plate hinge.

Fault code scan as well if you've got a scanner, that should throw up a code if it's a split pipe affecting your idling.

What about the temp sender? I'd check that aswell

Temp reading never goes above normal. I think a fault scan is in order. I'm going to ask on the north Wales area section since I don't know anyone with a scanner :/ I'll keep this thread updated on findings as it might be of use to others.

Where in north wales are you. If your anywhere near buckley try get dynod. Simon has got vag com snd is a top blok. Just tell him gav sent you.

Hawarden so yer v near. Where is he what garage?

Temp sender is a duel one, readings on ecu and temp gauge can be different

How can I test it then Raf?

Update - just cleaned the throttle body and replaced the cone filter with original Airbox and filter. Going out for a spin tonight.

Get dynod is on the pinfold industrial estate opposite jewsons.

Coolant Temperature Sensor is a obvious one to change, esp if coils/plugs are fine and it is ok with cold starting

been having this issue on my brothers car and was found it has a dead coilpack.

I've got an ebay lead and installed vcds lite, tells me what the gauge temp and the ecu temp is

Have you checked if its due a coil pack recall?

Ive had 3 coil packs replaced under recall the 4th was replaced before recall according to the dealer.

Well its seems loads better tonight after my changes. Smoother and faster but that could be due to cold temps tonight or wishful thinking. I'm going to give it a week before I come to any definite conclusions. As i mentioned at the start its intermittent so who knows what tomorrow will bring.

Keep you posted and thanks for the info all

changed the coil on my brothers car and it improved things but ti wasnt totally right. had a look at the throttle body and there was some clogging up in there so i gave that a clean and it seems sweet now. its passed it mot today so thats a good sign. hope you get yours sorted

Ok it's been nearly a week and my findings are it is running better after tb clean and refitting airbox. It did the sluggish/low boost thing once which was resolved as all ways by ignition on off (day 3). Shame because I was convinced that was a thing of the past. As far as idle is concerned it seems again better but not perfect as yesterday sat at lights I could just about feel a little juddering through the seat and the rev needle wasn't stable. I am running 95ron at the moment so I'll switch back to 98+ in couple weeks when there is fuel at the pumps. Cold starts seem ok too no kangaroo juice the past week.

I hate intermittent faults...

Can maf or coils be an issue? Thanks

I had the same, changed the maf and it wasn`t that..... so have a spare one you can have cheap if needed...

I should try temp sender/sensor . I haven't run it with the MAF disconnected yet either.