Kohler 9EOZD Generator-Coolant in oil

Maybe A Dancer · Dec 22, 2021

It's showtime folks !

Will close today or tomorrow on a new to me 1996 450DA

She has a Kohler 9EOZD genny with 150 (not a misprint) yes 150 hours

The unit features a sound enclosure.

Pre-purchase oil sample shows some coolant in the oil.

Boat has spent its entire life in a warm climate, so freeze damage is not a concern

Likely the required coolant changes were ignored and I am expecting to change the head gasket and send the head off to be magnafluxed.

Despite my best efforts, even on Boat Diesel, I've not found much info on this.

Anyone here had a similar experience?

Am I going to miss my Northern Lights 673 ?

BEST !

RWS

ttmott · Dec 22, 2021

Interesting that it's a Kohler; I thought these boats all had Westerbeke generators....

dtfeld · Dec 22, 2021

Congrats!

Not familiar with this generator, but if the coolant pump is gear driven might also be a source. But likely you’re on the right track with the head gasket…unfortunately.

Hopefully just a bad head gasket, not a cracked head.

Thornton69 · Dec 22, 2021

What level of coolant are you talking about? Milky oil and/or condensation collecting in the crankcase or vent tube? If not, I would be tempted to first pressure test the cooling system. If it is holding pressure fine, service it and take another oil sample after a reasonable amount of hours have been put on it with a decent load.
Reading your post, makes it sound like the genny is 25 years old as well. Was the oil replaced annually?

Maybe A Dancer · Dec 8, 2022

OP UPDATE -

Was just a trace of coolant in the oil

changed oil several times and sent off to Blackstone

zero coolant/water in oil

likely source was sloppy mechanic who serviced genset while at the same time changed CAT turbo freeze plug, added coolant to CAT at same time as oil changes.

Genset has been brought back to baseline.

All new hoses, new raw water pump, new exhaust mixer/riser/elbow, serviced heat exchanger, restored insulation in sound shield and now has over 500 hours with no issues.

Photos below

BEST !

RWS