the cause of a Bent Push Rod?

[Anothersearay]

:huh:
I have a bent pushrod in my 7.4 bluewater MPI mercruiser...
What is / or could be, the cause of this damage?

The pushrod is for the exhaust valve. second from the front..

The motor is a '97 -500 Hr, freshwater cooled big block.

Any Ideas?

Thanks!

 

[tobnpr]

Water in the cylinder would sure do it...

 

[Southpaw II]

A broken valve spring that has a broken piece of something in it could cause it.

 

[skibum]

I had a misadjusted rocker arm cause that in Chevy 307 once. Replaced it and got a bunch of miles out of it with no problems later on. A buddy of mine also had that happen to a single pushrod - twice. The same push rod bent within 3 months. We pulled the motor and tore it down, but never found an obvious cause. The guy at the machine shop we used said that a bad hydraulic lifter was the culprit. Visually, it looked fine. We did a standard rebuild on it using the same valves, heads, springs, and retainers. He never had the problem again.

Put a new one in it and run a compression check. Your motor should be fine if the valve didn't hit the piston.

 

[Happy Hour IV]

rusted valve stem / stuck valve due to water intrusion issue in exhaust manifold