Well heres the pics of the bottom end and no. 4 piston.




The troubling areas i think seem to be the blueish tinge to the edges of the crank between the bearing caps of the mains and piston ends. Most likley due to some sort of oil starvation.




This is the bearing of the number 4 piston, a fair few scruff marks on this bottom bearing and the other side had a few scratches to.




Thats the only scratches on the side of the piston i can find, the bores are smooth and no score marks in the bore either. The top of the piston isnt cracked or the ring land hasnt nipped the side of the bore at all.

The only conclusion ive come to is that theres been a slight lack of oil on that piston and that piston bearing needs replacing, i cranked the engine over by hand with the sump off and i DID hear a slight click or knock jsut as no. 4 was passing thru BDC (and on its way up again).

Any other noticeable defects anyone can spot? What about other diagnostic's that you guys can point me in the right direction?

Cheers
dave