Is the engine consuming significant oil? If the engine isn't consuming large amounts, leave it alone. Mine consumes about 1/2litre per 10000km and always has a good coating on the intake. It doesn't take much oil to make a mess. Yours, being from europe, also has EGR so that adds some soot to the mix, that is whats forming the paste in the intake. Pull the hose off of the EGR valve, plug it, clean up the manifold and enjoy. The oil won't hurt anything.
I hope you marked the position of the compressor and the compressor wheel in relation to the shaft before you removed the nut, otherwise you may have to get the turbo balanced at a turbo repair shop before reassembly. The K03 turbo is balanced after assembly. The compressor nut will have material removed from it to correct the balance, if it isn't reinstalled in the same location the balance will be lost.
the car doesn't consume large amounts of oil. the oil level only drop a bit after long motorway journeys..
all that oil and sludge may just be over the 80kmiles the car has done..
Note the k03's nut is left had thread don't ask me how I know :oops:.
teflon coating wouldn't be worth its benefits. Too expensive, but it can withstand 500 degrees C
