1.8 tsi misfire / stutter

[Cznski]

I've recently bought a 2011 1.8tsi octavia and it's a great car however it has an annoying misfire or stutter from cold. Seems to be most pronounced at about 2100rpm when on light throttle.

I've already replaced the spark plugs and coil packs but it's not made any difference.

Have read a few other threads on here about this issue but not been able to find any other solutions. The car is fairly high mileage at 69k but has full skoda history and I've checked with the dealer that there are no outstanding software updates or recalls.

Any ideas before I resort throwing money at a dealer as it's spoiling an otherwise brilliant car!

[Cznski]

Should have added there are no warning lights being triggered.

[DGW]

Have you had a diagnostic scan done to see what if any fault codes are logged?

[Cznski]

Not had a scan done. I take it then that fault codes can be logged without triggering a dash warning? Only had older cars before where any fault code would trigger a warning light.

Will get that checked out then.

Sorry if this is a stupid question but I have a basic OBDII reader but I assume I need something more hi tech for this car(VCDS?)....need to do some more research methinks, my automotive DIY experience doesn't extend beyond 2001 at the moment!

Edited 20 September, 2014 by Cznski

[blackspaven]

To a very minute degree, mine has done this from brand new. More an occasional slight hesitation than a full on stutter when accelerating slightly harder, just accepted it's part of the engine.

[brad1.8T]

Mine had a slight hesitation between 1500- 2000rpm.  Bluefin remap fixed that & it improved even more when I knocked out the first stage catcon.

 

Unfortunately in your case, I'd guess that it's a build up of carbon / oily gunk on the intake valves (which mine also has now that I'm up to 140,000km).

 

You can probably have a look using a cheap alibaba/ebay borescope in through the intake temp sensor hole.  Another way is to use an inlet cleaner such as Seafoam, Wynns direct injection cleaner or similar.  These are delivered via the inlet temp sensor port.  While they probably won't fix the issue, you should see some improvement thereby helping with the diagnosis

 

This might help

 

[Cznski]

Thanks for that brad - very helpful indeed. Was thinking of getting bluefin myself but obviously want to make sure there are no other issues lurking first.

Did a scan with my basic code reader which didn't come up with anything, I guess the next step is to get a full VCDS scan and will take a look at the inlet manifold as well.

[brad1.8T]

The other thing it might be is the inlet manifold tumble flaps but usually they will throw a code.

Carboned-up inlet valves will be worse when the engine is cold.