Misfire on idle

[Alasdair]

I'm just wondering if anyone can shed some light on a common issue that a few people are having;
Edition 30, happens warm or cold no eml light on fault logged for purge system, possible be n80 valve or carbon canister, could this cause a possible misfire.

I think the plugs was changed in October but will check on them tomorrow.
I did a readiness test on my little scanner and the cat failed along with purge system and engine management.
One thing I would say I have noticed an increase on how long the fuel is lasting but that could be me not using the car that much or driving more economical, I don't know but gets me thinking possible cat failure

Any help or experience would be great

[Tfsi_Mike]

What cylinder is the missfire happening. Ever notice anything under load?

[GrayMK5GTI]

Just to add to Mikes questions:

- is it just an odd stutter every 10 secs or so, or is it a very lumpy idle?
- does the rev counter move?


My old K03 GTI did exactly the same thing, I have put it down to carbon on the valves (67k miles). When I sprayed the wynns EGR cleaner in the inlet it did help a little, and as the car drives so well, pulls smoothly etc I'm not too bothered.

Awesome GTI seem to think its normal for TFSI's to do this at idle, and if you look on the other Golf forums a lot of others are having the same issue on K03 GTIs too as well as ED30s. . . .

Does anyone have a perfectly smooth idle without the slightest feeling of lumpiness in the drivers seat??

[Shaw]

My friends A3 Tfsi idles perfectly. Not a stutter at all even after idling for a long time. It's done 140k.

My golf is just a shade under 40k miles and it idles slightly lumpy. Makes no sense!


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[Alasdair]

Not too sure what cylinder ran round all my local specialists yesterday either too busy or shut .

Rev counter does not move when it's doing it.
You can start the car up and after a few seconds it does it then sets stops and does it again .
You can also here the pops from the exhaust too . Surely this can't be normal on them

[cander83]

Mine was maf needing a clean

[south]

mines like a tractor at idle with the odd 'lump' but no change on the rev counter... changed the plugs about 2-3k ago and car pulls fine with no misfires or other issues under load so I've put it down to a characteristic of the engine

[GrayMK5GTI]

Anyone else on the forum have a little "lump" in the idle?

[Saintsteve]

Dirty injectors 
Excessive carbon deposits around the injector tips and or inlet valves have excessive carbon build up.
That's what's causing your uneven idle, which is slowly coming poor apparent the older these engines run.Depending if you have been doing more town crawling will affect sooner then engines that have done more motorway miles.

[GrayMK5GTI]

Dirty injectors  
Excessive carbon deposits around the injector tips and or inlet valves have excessive carbon build up.
That's what's causing your uneven idle, which is slowly coming poor apparent the older these engines run.Depending if you have been doing more town crawling will affect sooner then engines that have done more motorway miles.

Steve - I had a go with Wynns Inlet & carb cleaner today. Made a small difference to the idle  

I sprayed it into the inlet with engine switched off, left it for 10mins then went out for a blast. Engine really doesn't like starting with that stuff in the inlet  

Looks like Alex @ AKS has bought a new machine for cleaning inlet valves  

[Tfsi_Mike]

Has he bought the walnut blaster thingy? 

[anorganix]

Hi mate, is it VCDS missfire or rough/variable idle?
Have you checked for dirty MAF and/or failed PCV?

[GrayMK5GTI]

Has he bought the walnut blaster thingy? 

I read that in your build thread Mike 

Hope it's true

[Tfsi_Mike]

Has he bought the walnut blaster thingy? 

I read that in your build thread Mike 

Hope it's true

Oh thought he'd actually been out and got it.  Don't think he has it yet

[Markyed30]

Dirty injectors  
Excessive carbon deposits around the injector tips and or inlet valves have excessive carbon build up.
That's what's causing your uneven idle, which is slowly coming poor apparent the older these engines run.Depending if you have been doing more town crawling will affect sooner then engines that have done more motorway miles.

Steve - I had a go with Wynns Inlet & carb cleaner today. Made a small difference to the idle  

I sprayed it into the inlet with engine switched off, left it for 10mins then went out for a blast. Engine really doesn't like starting with that stuff in the inlet  

Looks like Alex @ AKS has bought a new machine for cleaning inlet valves  

I think you may be lucky you didn't hydro lock ur engine I'd never consider doing it without the engine running?