id call it oil starvation. common problem in gt-r's without the r34 oil pumps.
this is an amazing machine that is extremely well taken care of. it will cost you $20k+ to buy a $10,000 gtr and get it to where this one is now.
with that rebuilt motor, the next service you will need is the timing belt 100,000km from now.
awesome deal tyler, sad to see her go!