Mercruiser 3.0l push rods bent

[mewalker]

I have a 2000 glastron with the 3.0 mercruiser. This spring I had to have the head shaved. I installed everything per the service manual number 26. I took the boat to the lake for a test ride. I found the valve cover had a leak but the engine ran fine. I tightened the valve cover. Two weeks later we took the boat out, it ran fine for about 3 hours then all at once it lost power. the engine still runs but not with a lot of power. long story short all of the push rods with exception of 2 were bent, the number 1 exhaust push rod was broken. any ideas on what may have caused this? PS this is my first post and thanks in advance.

 

[Bt Doctur]

tight valve guides, rusted valve guides, valve timing incorrect and valve hitting the pistons

 

[mewalker]

Would the over heating have caused that

 

[Bt Doctur]

you said a shop shaved the head, you have to remove all the valves to do that operation . So it would make sense they checked/replaced/knurled the guides to the correct size and then installed the valves

 

[Villain lll]

Why did the head have to be shaved? Anytime you tighten the clearances by trimming the head, the backlash distance changes for alignment of the pushrods, the valve clearances change, the compression changes, etc. It's not something I'd expect that anyone would "have" to do to their engine. If the head was warped, I'd expect to change it out. Something doesn't make sense here. You clearances or tolerances must have not met spec, especially once the engine ran up to operating temp.

 

[JaCrispy]

They don't cut the head that much to cause any mechanical issues. Anytime I replaced a failed head gasket I always sent the head out for resurfacing. There are guidelines as to how much warp is acceptable or repairable.

 

[mewalker]

The head had to be resurfaced because I was a dumb ass and didn't hook water up to the engine while I adjusted the carb after rebuilding it. the engine ran hot and warped the head. Went by the head shop today and they said the valves stuck, that is why the push rods bent.