Hey guys. My 2.0 tsi is currently suffering with a pretty severe cold start misfire which then calms down but it is throwing random misfires across all cylinders. So far its had all new spark plugs,PCV, coil packs, fuel injectors and fuel filter. The cam timing has been manually checked and is fine so its not a timing issue. Dealership now seems to think its a carbon build up which is likely but they also found some oil leaking from the rear of the engine so im inclined to think the rear main seal has gone as this can produce those exact symptoms. Its costing me a small fortune and doesnt seem to be an end in site yet....
They found a significant amount of fuel mixed in with the oil indicating an failed fuel injector. After replacing those it has made the idle better as the revs were drifting around before but the misfire continues. The cylinders have been pressure tested and came back fine.