Scirocco 2.0tsi misfire on tickover.

[gord115]

My 47k mile Scirocco 2.0tsi petrol has started to misfire terrible on tickover.
Above tickover it runs ok most of the time but sometimes misfires all the way through the revs.
I've had it to a vw independent specialist who thinks it is the timing that is out (timing chain)but doesn't have the gear to do the job. He was a bit vague,as if he wasn't sure.He says take it to a main dealer!
I've spoke to someone else who is going to have a look Monday.
If it was the timing chain wouldn't it miss all the time?
Could it be the tensioner?

Any help appreciated.

[Cuprabob]

First thing I would check is the coilpacks quickly followed by the plugs.

The timing chain stretch can be checked on VCDS by the relationship of the data from the crank sensor to each cam sensor. If it was that bad it was causing a misfire I would have thought the EML would be on.

Connect to VCDS and see what faults come up.

[gord115]

Apparently the coil pack is ok.
He said loads of fault codes came up though.
He was a bit vague as if he wasn't sure.

[Cuprabob]

If that's the case take it to someone with a bit more knowledge whether it be a dealer or specialist.

[gord115]

Someone else having a look Monday.
Will let you know how I get on.

[Cuprabob]

Please do and I really hope it's not the timing chain, for your wallet's sake

[gord115]

Please do and I really hope it's not the timing chain, for your wallet's sake

How much we talking?

[gord115]

Update from guy who looked at my car,his receptionist has told me he didn't scan the car,he just thinks the timing is out due to the cam chain.
Apparantley he doesn't have the kit to do the job.
This is an Audi/VW specialist I have used for 13 years.

[Technane]

Update from guy who looked at my car,his receptionist has told me he didn't scan the car,he just thinks the timing is out due to the cam chain.
Apparantley he doesn't have the kit to do the job.
This is an Audi/VW specialist I have used for 13 years.

An Audi/VW specialist that can't scan a VAG.

he needs to be kicked out of the trade making that kind of claim! at the very least being a garage u'd expect him to have something that can scan the faults if not code the modules!

[gord115]

What is scanning exactly?
When I first went to him he plugged in his laptop to the OBD port and said loads of codes were coming up. Is this the same as scanning?

Sorry for being a noob

[Cuprabob]

Yes, scanning is reading the data through the OBD port using a Diagnostic tool or diagnostic software such as VCDS.

Often there are loads of fault codes but the key is to understand and differentiate between cause and effect and which ones are irrelevant.

For example if you have low battery voltage that can trigger numerous fault codes in each of the Canbus Modules.

It can't be misfiring badly as if it was the unburnt fuel would trigger an EML as the Lambda probe would be reading high.

I would let the car tickover and disconnect each coilpack in turn and if you remove one and there is no change to how rough it's idling that's the cylinder that misfiring. I would then swap coilpacks over from another cylinder to see if the fault follows the coilpack or remains on the same cylinder and take it from there.

[gord115]

Ok. Just got a call off garage that has fixed my car.
It was the timing chain that had stretched-at only 47k!
Cost my £97 for chain kit and £250 for labour (mates rates)
Absolutely chuffed.
As for Volks-tek of Dronfield who didn't want to know,they have now lost a loyal customer after 13 years.

Thanks every one for your help.

[C00kie]

I have a very similar issue...car shakes/judders every few seconds when ticking over. No EML and the rev counter is stable, not jumping. Only notice the problem when the car is idling once it has warmed up and revs have settled down to around 800rpm. Already changed all coilpacks and plugs, no difference.

Will post an update once I've had it looked at and (hopefully) sorted!

[C00kie]

I have a very similar issue...car shakes/judders every few seconds when ticking over. No EML and the rev counter is stable, not jumping. Only notice the problem when the car is idling once it has warmed up and revs have settled down to around 800rpm. Already changed all coilpacks and plugs, no difference.

Will post an update once I've had it looked at and (hopefully) sorted!

So I had the local VW specialist look at it today and they couldn't find anything wrong with it. Scanned for errors - no faults, checked for air/vacuum leaks and all good seemingly. They said it could be an intermittent fault with one of the fuel injectors, but not worth replacing without knowing for certain as it would be pretty expensive.