Yanmar Engine Heat Exchanger

Sep 5, 2012
18
Hunter P42 San Francisco
Hello All,

Last weekend I was changing the oil in my Yanmar 4JH2-TE diesel engine on my sailboat and was in a hurry. After extracting the old oil I began filling with new oil thru a funnel. Oil began overflowing almost immediately. I realized that I was putting oil in the Heat Exchanger rather than the drive engine. I estimate the I put in 3 or 4 ounces of 15-40 weight in the heat exchanger. Does anyone know how deleterious this will be on the heat exchanger? Is draining and replacing the coolant fluid enough? Do I need to flush the heat exchanger? With what?

Thanks for any comments,
Schooner39
 
Oct 29, 2005
2,362
Hunter Marine 326 303 Singapore
Lets start by NOT draining. Oil floats so filling the exchanger with water will bring most of the oil out. Of course you've to clean up the engine and compartment later. Don't know what the residual oil would do to the cooling circuit.
 

Johnb

.
Jan 22, 2008
1,461
Hunter 37-cutter Richmond CA
Agree with Ken, plus I would get some hydrophobic absorbent and attempt to blot up as much of the oil as I could - without letting any of it get into the water tank.

That stuff is good to keep on hand anyway, our marine hands it out for free.
 
Sep 5, 2012
18
Hunter P42 San Francisco
That's a good idea, I'll try that. Thence, I'm thinking of flushing the system with a detergent solution?

Schooner39