Quote Originally Posted by Lucas_R View Post
Some good info in this post relating to the 118TSI misfire: Golf 118 TSI Engine Failures and Service Campaign 24S4

VW revised the software for the 118TSI engine (and DSG) several times to try and cure the issue these things have with blowing themselves to bits. Would be a good idea to check you have the latest version of the software.

Also remove your spark plugs and check their gap. Gap to 0.7-0.8mm. If they are gapped at 1.1mm then this will be contributing to misfires.

Otherwise i suggest you check/replace the cam solenoid because when these get old they fail to operate smoothly and cause the engine to intermittently die (for like 0.5-1.0 second) which feels like a big misfire (my Subaru has this issue at the moment and i just purchased 2x new cam adjuster solenoids to fit). I also had to change this part on my Mk6 GTI a few years back.

Also check/replace your fuel filter, because if this is dirty/clogged then it could temporarily starve the engine of fuel at certain times causing a misfire. And while you are checking fuel related items, might be a good idea to check your fuel pumps (the in tank low pressure pump as well as the high pressure fuel pump (HPFP) driven off your intake cam).

And lastly, make sure you are running the engine on 98 octane premium fuel. You could probably get away with 95, but for the extra $1 it will cost you to fill up with 98 I wouldnt risk it.
All very sage advice. The car was scanned after the last DQ200 accumulator recall and came back up to date. I exclusively use 98, V-Power or Ultimate. My mechanic tells me there are 2 part numbers for the spark plugs with different gaps and the ones he used have 0.8mm. Only 2 phasers on your subi? My wife's 86 has four of them! Anyway, the old Golf is running fine now, but thanks for the tips!