Mercruiser 140 (3.0) stuck valves

[anesthes]

Hi Guys,

I've got a 1984 Glastron with a 140hp 3.0. It was winterized and not used for about 6 years. The other day I changed the oil and OD oil, and tried firing it up.

I've got 40psi oil pressure when cranking, but it won't catch.

I then did a compression test and got 90, 0, 0, 90

I took the valve cover off and found that the two exhaust valves on the two center cylinders were stuck open. Rockers and pushrods are fine, the valve is literally rusted to the guide in the open position.

I don't know if I want to rip the head off and have it re-done, or just part out the engine.

Are these interference motors, as in, with the valve open would it have smacked the piston while I was cranking it ?


-- Joe

 

[Bt Doctur]

its possible, you wont know until you pull the head

 

[flipbro]

Head has to come off no matter what. Even if piston didn't hit the valve. It still needs to have the head done..

 

[anesthes]

Head has to come off no matter what. Even if piston didn't hit the valve. It still needs to have the head done..

Oh I realize that, it's just a do I bother or scrap the engine type of question. Like, I know certain automotive engines are interference motors so if you snap a timing belt or something you know the engine is junk. I'm curious if this is the case, if so, I won't even bother with it.

-- Joe

 

[Alumarine]

It's not an interference engine. Not saying it's impossible for a valve to contact a piston though.
Well worth pulling the head.

 

[anesthes]

It's not an interference engine. Not saying it's impossible for a valve to contact a piston though.
Well worth pulling the head.

Okie dokie. Thank you for the info. I guess I'll pull it tomorrow and get an idea what it will cost to have the head redone.

Thanks guys!

-- Joe