Quote:
Educate me here coops, a buggered big end is bad news by all accounts, but why would it drop the compression
Dont' get me wrong...... A spun big end wont' always drop the compression, but quite often the spinning bearing will create eccentric forces on the rod & piston which, over time will cause the bore to wear, thus reducing compression.
I should have asked if there was a 'knock' that accompanied this drop in compression.... If this is the case it is almost certainly a spun big end bearing.
It was the fact that 3rd or 4th bearings spinning are common on CA18DET's (due to oil supply problems at high rpm) that made me think it was a big end problem.