I learned of a Service Bulletin regarding ECI cylinder pushrod shroud retainer springs. Apparently some of these springs were incorrectly manufactured and are subject to breaking. The SB has you check to see if the earlier version of the springs are installed on the engine and replace with the newer spring which is thicker and not subject to the flaw.
It's is an easy check and I first removed the valve covers, then loosen the hex nut and removed the retainer springs. The old flawed springs are 0.032" thick and the newer ones are 0.040". All of mine measured at 0.040". The springs on my engine are the newer springs and not subject to the SB.
I replaced the retainer springs, nut and valve covers.
