Quote:
Originally Posted by RustyBucket
A new cam won't fix 75lb. cranking compression on #5 if the lobes on #'s 2 & 4 are wiped. Have you disassembled the engine & seen the cam or determine this from the rocker arm travel? If the cam is flat the metal went someplace.
|
Cylinder #5 has a separate problem, it failed a leakdown test which appears to be from a burnt exhuast valve. In #5s case, the exhuast valve won't seal, and air whistles right past the valve during a leakdown test.
I diagnosed the flat lobes on 2 and 4 by watching rocker arm travel, I actually used a dial indicator on them but it was really unnecessary. They only move about .050 of an inch at the pushrod. So I think after all, the miss I felt was from number #2 cylinders exhuast valve not opening and backfiring through the intake.