Slight engine misfire at idle

[TomC]

I had an oil change done by Transporter yesterday (very good mobile service he provides btw!) and he picked up on a slight ocassional misfire, as we were standing by the engine idling.

This could have been happening for some time and I haven't noticed it. But it got my to thinking, have any other TFSI owners have/had this? Car has never thrown a code and and it's never showed an error when scanned (inc. the scan Transporter did yesterday) so I'm assuming it's not an overly big issue at this stage.

What can cause it? Modifications (mine are in my signature below), excessive carbon build-up, coils going off etc? Anything else I should be looking out for?

I assume it's only happening at idle, although i wouldn't know what it would feel like while driving. Haven't had it happen in my previous cars (like a lot of other things the Golf does to be honest :p) so I need some education

[dubsweeper]

I had an oil change done by Transporter yesterday (very good mobile service he provides btw!) and he picked up on a slight ocassional misfire, as we were standing by the engine idling.

This could have been happening for some time and I haven't noticed it. But it got my to thinking, have any other TFSI owners have/had this? Car has never thrown a code and and it's never showed an error when scanned (inc. the scan Transporter did yesterday) so I'm assuming it's not an overly big issue at this stage.

What can cause it? Modifications (mine are in my signature below), excessive carbon build-up, coils going off etc? Anything else I should be looking out for?

I assume it's only happening at idle, although i wouldn't know what it would feel like while driving. Haven't had it happen in my previous cars (like a lot of other things the Golf does to be honest :p) so I need some education

I did a oil change in my 07 gti , and i have the same problem at idle after driving until its warmed up , it is very faint , i do have some new spark plugs ready to put on , but it could also be coil packs ?

[thezoneR32]

I have this issue aswell but mines done 168,000km so its not surprising. Plus I have another bad mechanicle rattle issue stilll not sorted coming from the top of the engine so the misfire seems irrelevant to me.

[TomC]

I have this issue aswell but mines done 168,000km so its not surprising. Plus I have another bad mechanicle rattle issue stilll not sorted coming from the top of the engine so the misfire seems irrelevant to me.

I've been looking closely at the other thread you've been posting in also, as your symptoms do sound similar to mine (albeit a little worse it sounds like )

The next two steps for me are the check the coil packs for failure, as I don't think they've been replaced from the factory ones. Assuming they're ok, I'm going to have a carbon clean done by Transporter with his equipment next service.

[thezoneR32]

My coils are done. Its a campaign (recall) did you know that?

Hmm, Transporter does carbon cleans? Might have to give him a visit.

[dubsweeper]

My coils are done. Its a campaign (recall) did you know that?

Hmm, Transporter does carbon cleans? Might have to give him a visit.

I had a recall for a ecu in 2010 , have the mettalic sticker inside the door , so if i take it into a dealer will they look into the problem i have as above in this thread ?

[Jmac]

Ive changed a few injectors now on the Mk5, although it was picked up a random misfire, by the way this get thrown by the carank sensor, so get it diagnosed if this code arises, as ign misfire and lean or injector is all picked up by the crank sensor. Anyway back to the begining just bought an injector replacement tool. bloody dear but looks like i might see more as the model gets older.
PCVs are bad too but enough gets said about it. Anyway oil vapour will cause tha on ANY engine
Cheers
Jmac

[TomC]

Ive changed a few injectors now on the Mk5, although it was picked up a random misfire, by the way this get thrown by the carank sensor, so get it diagnosed if this code arises, as ign misfire and lean or injector is all picked up by the crank sensor. Anyway back to the begining just bought an injector replacement tool. bloody dear but looks like i might see more as the model gets older.
PCVs are bad too but enough gets said about it. Anyway oil vapour will cause tha on ANY engine
Cheers
Jmac

Looking through the parts on this list, I had the injectors replaced during 60k service 15,000km ago so doubt it's those? I had my original PCV and DV updated to the newest OEM revisions 10,000km or so ago so prob not those either. No codes had been thrown when the car was scanned last week by Transporter. Next week he's going to test some new gear of his and monitor each cylinder to see if the mis is in one or across the board (which might suggest the ol' carbon buildup I think!).

My coils are done. Its a campaign (recall) did you know that?

Hmm, Transporter does carbon cleans? Might have to give him a visit.

I checked with Solitaire last year when I first heard about this and apparently my car was not part of the campaign... Affected certain coil batches only, dependent on the individual car's VIN (or so I was told )

[DNA Tuning]

While the car is doing idle/additive fuel adaptations, there can be *very* minor misfires that most wouldn't notice/feel.

Try unplugging the MAF and see if it stops momentarily; unplugging the MAF takes the car into open loop and so it won't be adjusting any fuelling on the fly.

This will log an error code though so it will have to be cleared. You can use the SRS-II to do this. =)

[dubsweeper]

I had a recall for a ecu in 2010 , have the mettalic sticker inside the door , so if i take it into a dealer will they look into the problem i have as above in this thread ?

Called the Vw service centre in perth today , gave them my vin number and turns out mine did have a recall , which explains the miss fire ....

So my 2007 gti has had two recalls 1 prior to me owning it , ecu recall which i think was a remap , 2 the coil packs ...

happy to know they are going to replace them for free .

[Youngc29]

I had similiar issue, got all 4 coil on plugs replaced, was good after that, wasnt covered in a recall on my VIN, my08 built 07.

[dubsweeper]

I had similiar issue, got all 4 coil on plugs replaced, was good after that, wasnt covered in a recall on my VIN, my08 built 07.

had them replaced a few days ago .... but the slight rough idle is still there after the car has been running for a while ! think i might do a carbon clean now ....