So ever since I've owned my t, I've been battling a pretty severe oil burning issue. im burning about 1 Litre of oil per 800ish kms. car has 167000kms and a battery relo, cat back exhaust and no tune.
SYMPTOMS
the car will blow blue/white smoke upon start up, (usually more if left for longer periods), will blow smoke upon acceleration after waiting at a stop light, and will sometimes blow smoke after giving it some on the freeway after cruising.
the turbo has previously been replaced along with new oil feed lines.
first thing I did was remove the coils (completely dry, no oil in spark plugs wells). Then I removed the plugs, most of which looked old but indicated no oil burning, except cylinder 5.... which was covered in thick carbon deposits on the electrode and was even dripping wet with oil. while the plugs were out I did a compression test which showed 200-210 psi across all cylinders so I believe the compression rings are fine.
Next I inserted a borescope into the combustion chamber of each of the cylinders. and cylinder 5 again showed a pool of oil on top of the piston. keeping in mind the car had been sitting for an hour or two to cool down before I started to work on it.
I've heard valve stem seals are very rare to go bad but given this info how confident can I be without taking the head apart? maybe rings?
