Westerbeke 4-107 Cooling water to oil leak

[mesayousa4]

I have a 1972 Westerbeke 4-107 engine which appears to have a cooling water to oil leak. Has anyone else had this same problem? I have a friend in town here with the same engine and same problem and we are both trying to decipher it with little success.

[Fishspearit]

blown head gasket?

[40 South]

If it is wet liner, could be a liner seal.

[Wainui]

Had the same thing with a 4-108
Oil Cooler had a tiny leak.

[mesayousa4]

Head gasket seems unlikely because I am still getting really good compression. Possible it's still related even with good compression? Friend who had same problem found no problem with head gasket.

What are you referring to RE 'wet liner', I'm not familiar with the term and sounds interesting?

Good call on the oil cooler, I'll double check that. Only reason I didn't look at it was that we found what we believe to be ethylene glycol in the oil as well as water. If I could manage to confirm this it would rule out the oil cooler, as that it is seawater cooled on this engine.

[40 South]

A wet liner is the a cylinder bore liner that is pushed into the block casting and acts as the cylinder bore/wall that the piston moves in. The coolant circulates around the outside of the liner to keep the cylinder cool. If the liner is "out of round" or the seals do not seal to the block, coolant can leak directly to the sump.

[irwin37]

4-107 is a wet liner, 4-108 is a press fit dry liner. I think you could have weeping of water in head gasket with out it being blown. Mine was seeping between a water port and oil, but still had good compression.

John

[River Cruiser]

If it is only water some Westerbeke raw water pumps that are gear driven can leak water into the oil when the shaft seal fails. On updated pumps they had a longer shaft with a redesigned housing that cured this problem.