Cold start misfire and misfire across of cylinders

[pburgess22]

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.

[pudding]

It's definitely a TSI EA888 engine?  If it is, then rear main seals going is a known problem when the PCV fails.  The seals aren't as robust as the older EA113 engine (TFSI).  Has it had a leak down test to see if they can hear air escaping into the bell housing?

Fuel mixing with the oil is usually a sign of a high pressure fuel pump problem.  Not sure if that's common on the EA888 or not.  It's not mega common on the EA113.

Carbon build up doesn't and shouldn't cause cold start problems.  Mine's on 111K and not been decoked.  It always fires instantly up to a smooth idle. Is your intake manifold flap actuator broken?  That can cause bad cold running.  A very common issue on the TSI engine. 

[pburgess22]

It's definitely a TSI EA888 engine?  If it is, then rear main seals going is a known problem when the PCV fails.  The seals aren't as robust as the older EA113 engine (TFSI).  Has it had a leak down test to see if they can hear air escaping into the bell housing?

Fuel mixing with the oil is usually a sign of a high pressure fuel pump problem.  Not sure if that's common on the EA888 or not.  It's not mega common on the EA113.

Carbon build up doesn't and shouldn't cause cold start problems.  Mine's on 111K and not been decoked.  It always fires instantly up to a smooth idle. Is your intake manifold flap actuator broken?  That can cause bad cold running.  A very common issue on the TSI engine.

The fuel pump has been tested and was providing the correct pressure at several rev ranges or are you talking about another issue ? How much does a fuel pump set you back normally ?

I cant check the engine number as im currently offshore and will be for the next few week.
I hasnt had a leak down test as far as i know as VW seemed certain it was injectors and after changing those its no different. They didnt make any comments about the manifold actuator so no idea if they even took something like that into consideration. Feel like the dealership is messing me round but it was the only place able to look at the car locally before i went offshore.