Top End Rebuild

[srisitt]

So I have a leak at the cylinder head on a Ranger with 259k miles. Still runs well, fluids not mixing, compression feels good, and no smoke, so I think it’s just external. Still reliability is very important here, so I’m considering replacing the gasket.

It also has a tick when the engine is cold. Not a big deal, but if I’m replacing the head gasket I might as well replace some push rods and rocker arms.

Would it be worth going through the top end of an engine with this many miles? I’ve also heard that you don’t want to just rebuild top ends because it can cause issues like oil burning, is that true?

 

[Elutheros]

I'm just ready to put the replacement heads on my 1991. My machine shop guy thinks the 4.0 is a multi hundred thousand mile engine so I'm going to press ahead with new heads and valve train. New rocker arms and pushrods are also being included. It costs about $350 plus to get bare new heads, a hundred $ to transfer all the valves and springs, another $275 in the parts and gaskets. Mine had remanufactured heads on it and they were patched up with incorrect size valve guides which resulted in leaking due to valves wobbling around--hence low compression and bad valve seats. Once I saw that I decided against remanned heads.

 

[srisitt]

Also curious if there’s a way to check the condition of the bottom end without pulling the engine, or would a leak down/compression test be the best way to determine that?

 

[black_demon69]

just rebuilt my 4.0l ohv @about 206,000 because i was looking @ about $1000 too do the heads or $2000 to do the complete rebuild myself...

i could have just done the heads and probably been fine but I really don't want to go back into it for a very long time. lol
i am glad i did the rebuild it runs great..

 

[sd359]

I have 94 ranger 4.0 with 218,000 and have what seems to be head gasket or crack don't know which yet. I have a donor motor with 100,000. I can rework and switch heads but I think I am going to go through the spare motor and replace mine. I have been looking at prices depending on what all I change I will have to spend anywhere from about $1000-$2000 to rebuild the spare motor. If you have the cash I would do complete rebuild instead of top end.