450: Generator Head Gasket Replacement

[gatorsailor]

Ladies, Gents,

Anyone have any experience or a good guess on what it would cost to replace my head gasket on my 11KW Onan Generator in my forward lazerette? It's a pretty large space and no problem getting a torque wrench in there so I'm almost positive nothing will have to be lifted out.

Thanks in advance,
Greg

[Bean Counter]

Sorry never had it done. I would be interested to know why/how the gasket has gone and how many hours on the Genny and what the symptoms were.

I looked in a service manual for a similar Onan, just guessing I reckon half a days work if the only issue is the gasket.

[Cheechako]

Real hard to say. Most diesels you can have the head off in 1/2-1 hour. (depends on what in mounted on the engine to get at it!) Clean up probably another hour.
But I think things need to be looked at to discover why the gasket failed. So you are probably talking having the head pressure tested and maybe ground flat for a proper job. So another 1-2 hours driving time, shop fees, reassembly, torqueing, adjusting valves etc. Maybe 8 hours total. $800?

[gatorsailor]

Thank you for the replies and sorry for the late response on my part. Tried to run down to the Caribbean and sail my Lagoon 450 back to the States but the Nor'easter patterns ended up keeping us pinned down so I had to leave her behind and will try again next month.

My generator is an Onan 11kw and is 4 years old with about 1000 hours on it. I had the engine oil analysed and it showed engine coolant in the oil. I'm going to go through and replace all the possible gasket leaks first and see if I can stop it. She runs great and there are no other indications externally of a problem. I had a compression check done on her and that checked out normal on all cylinders.

Anyone have a recommendation for a sequence of checks/inspections/gasket replacements I should undergo before considering internal damage/Head Gasket?

Thank you,
Greg

[Krabimike]

maybe try a second oil sample test? 1000 hours. no compression issues not visual. Seems like it may have been a bad test?