ED30 -Misfire Disappears

[richtung]

Morning folks,

Had a weird experience yesterday. Parked the Ed30 up to go to the gym. Came back (1hr later) and started up - no problems. Drove all of 100 meters when the car started juddering, running really rough and engine management light flashing. Pulled into a nearby petrol station and switched off. After 1 min, switched back on - Engine management light no long on or flashing but engine running very rough. Plugged in my ODB reader and Torque found a stored error - P0302 - Cyclinder 2 misfire detected. Switched off and called the AA.

After 20 mins or so, i tried the engine again - this time it starts perfectly with no rough running  . Took the car for a spin round the block and all is fine. I was about to cancel the AA man but he shoes up. I told him whats happened but he still wants to take a look. His diagnostics showed the same stored code. He takes off engine cover and gets the coilpack and spark plug for cylinder 2. Both look fine. he re-assembled, cleared the stored error code and re-scanned - no new errors detected.
He says that if the coilpack is at fault, their diagnostic machine does usually indicate specifically the coilpack being at fault. On this occasion, it just confirmed a misfire on Cyclinder 2. He also said that sometimes some dirt can foul up the injector temporarily and eventually sorts itself out. He sent me on my merry way.

So, has anyone ever head a misfire on one of the cylinders but the issue just goes away? Im not really sure what to do now - there's no new faults or anything but my confidence is dented a little -  every time I'm about to start the car, i say a little prayer! Any advice?

Thanks Guys.

Rich

[Dan_FR]

Get it on VCDS and check the misfire counter. Plugs and coils usually show the first signs of failing under significant load. When mine were going I just had a misfire code rather than a coil-related code.

My worry is a failing injector - all too common on K04 engine cars and it is a potential engine killer if left unchecked.

[richtung]

Get it on VCDS and check the misfire counter. Plugs and coils usually show the first signs of failing under significant load. When mine were going I just had a misfire code rather than a coil-related code.

My worry is a failing injector - all too common on K04 engine cars and it is a potential engine killer if left unchecked.

Cheers Dan. I dont have access to VCDS as such.

Does a failing injector throw up any error codes?

[Dan_FR]

None at all, just misfires at idle and under light loads to start with. You won't be able to access the misfire counter with Torque or any other OBD2 protocol interface, needs to be VAG specific.

To be fair it doesn't sound like the case for you and I suspect that if the issue has resolved itself then it may be hard to pinpoint. Swapping coilpacks and/or plugs around while the issue is there will help narrow down the issue, but you still need access to the misfire counter rather than waiting for a code to pop up