Yeah, oil pumps on these cars are the stuff of restless nights lol. I didn't know about the TFSIs until I saw a couple of American vids on YT. The hex key on the 2.0 TDIs has at least a relatively straight foward and bullet proof solution: a re-engineered kit taking it from 77mm to 100mm with hardened materials, from a firm called KMB. Not exactly cheap - £750 approx all in - I had it done at the last cambelt change, and we're on almost 280K now. But I still have anxious moments, thinking I should have changed the oil pump itself too while the sump was off, for another 200 quid, since wear on that part of the shaft was identical to it on the balance shaft (see photo). I may do it next cambelt change, depends on pennies.
I don't know much (anything) about this VIS/freewheel solution you both talk of, but some on the TDIs opted to delete the balance shafts and use a 1.9 TDI chain driven oil pump. Whilst solving the issue, there was no way I was going that route. It really robs the 2.0 of smoothness and refinement. 4 bangers have poor secondary balance and really need balance shafts for it. The legendary 1.9s are very long lived but they are pretty agricultural too IMV.
What I reckon though is in all these cases, after countless hours research everywhere, one overiding factor is frequency of oil changes. The longevity of these engines is really quite good in almost every case where people avoided the marketing BS, lease aimed, LL services intervals of 18/20k. A maximum of 10K, preferably 6-8k, was pretty common to those that lasted longer than others.
