RunNE1

iTrader: (1)

The car has had a slight knock/tap for a while. It got much worse after a recent oil change. I did a compression test and the results were 210 with a range of ~15 psi. The compression would build up in steps. Usually the first rotation would hit about 80-100 psi and then step up to 200-210 at five strokes. I also pulled all the pushrods and none of them were bent. One very unusual thing I noticed was one of the pushrod holes was slotted instead of a circle, but the pushrod did not have any damage. Any suggestions? I checked past threads, but nothing I have checked so far suggests any problems.

RunNE1

iTrader: (1)

Ran the compression check again. On two cylinders,(front two on the left bank) the first stroke did pump up to a lower pressure 100-120psi whereas he other cylinders would hit 150-160. I added oil and the cylinders did pump up to the same level as the other cylinders on the first stroke. Once again, all the cylinders did hit ~210psi after four strokes with a range of about 15psi across all the cylinders. Is this a sign of a ring problem?

RunNE1

iTrader: (1)

Put the covers back on today. Here is a pic of damage I found:




Not sure when this happened, but I did not see any damage/marks on that pushrod. The car started fine. The knocking is still there. Tried the screwdriver/steth trick and could not find the source of knocking.