Possible misfire

[selleym]

I have noticed on a few occasions that when pushing hard mainly down a slip road it feels like it skips a beat, loses a bit of acceleration for a fraction of a second!
I'm guessing this is misfire?

Would this not show a warning light on the dash?

I may be imagining it

Any ideas?
Thanks

[Cuprabob]

The odd misfire won't trigger the EML. There needs to be enough unburnt fuel going down the exhaust for the pre-cat lamda to record a higher than normal fuel/air ratio.

Keep an eye on it as it could be a sign of a failing coilpack.

[selleym]

Cheers
Is it anything to worry about for now? Still under VW used warranty.
Doesn't happen often.

[Cuprabob]

I wouldn't say it's anything to worry about at the moment. If you have access to VCDS, you could check if any misfires and against what cylinder number. Even although tbe EML light is not on, the ECU can still record misfires.

[Gaz r]

Mine had a slight rough idle the other day. The next day it was fine but took it to a garage and checked for errors on VCDS, nothing came up apart from a fuel cap error from about 5 months ago.

[norco]

Mine misfires when its cold. Its really annoying me now Got another thread open so wont expand here Good luck with your problem.

[BAIKAR]

There seems to be an ever increasing amount of posts relating to 2.0 tsi engines misfiring, jumping and hesitating. I've had the same fault in my car for the last few months. A feeling of power loss at higher rpms before a gear change. I changed the diverter valve as it was the least expensive and they are prone to split. My old one was still intact when removed. I then read a lot about the flap inside our manifolds but mine seems to be working normally.

I connected the car to my vcds and was able to see various cylinders producing the odd misfire. The car never brought on the check engine light. The misfires were never more than 2 or 3 on individual cylinders so I've decided to change all 4 coil packs and plugs and get back the car I used to love. I have the parts ready to replace and will report back on the results. It's not a cheap fix but replacing 1 or 2 coils did not seem sensible. Replacing all at the same time should hopefully eliminate any future problems with the coils that seem fine at the moment.

[Cuprabob]

Problem is that your warranty is with Arnold Clark so even if an indy identifies the problem, to claim on the warranty you'll need to take the car back to AC and they won't believe the indy and want to confirm diagnosis.

[shshivji]

It could even be excessive carbon build up on the valves due to the engine being direct injection, quite a common issue with the tsi's.

Shak

[selleym]

Problem is that your warranty is with Arnold Clark so even if an indy identifies the problem, to claim on the warranty you'll need to take the car back to AC and they won't believe the indy and want to confirm diagnosis.

Whose warranty is with Arnold Clark?

[Cuprabob]

Either I'm going senile or I've responded to the wrong thread☺

[norco]

Its mine Cuprabob Tempted just to replace the coils myself as one did fail about two months ago and was replaced by the RAC. The mechanics did say they swapped them round during their tests but I was unconvinced that would actually have any effect. I'm not hugely knowledgeable about engines so not in a great place to argue.

[BAIKAR]

So I finally got the time to change over all four coil packs and plugs. The coil pack part number now ends with a B compared with my original ones. I also checked the plug gaps in the old ones which were replaced about 6 months ago. I didn't bother checking them before as I presumed they would be correctly set out of the box. RW1 recommended 1.0 - 1.1 mm and I found all plugs set to anything between 0.70 and 0.80 mm. The plugs also looked very black with carbon deposits. Then I connected my VCDS and checked the measuring blocks for misfires. I ran the car at idle and fast idles with no misfires being detected. I will be driving the car this evening and will report back after a road test but so far it seems to have cured my problems.