Kohler running hot

M

mawyatt

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Joined
Jan 28, 2008
RO Number
29307
Messages
202
We have a Kohler 7.3ECD Low Co generator on our SeaRay 2008 that is running hot around 210 degrees. Long story short is, I have replaced the impeller (the replaced one was fine, no vanes missing), flushed the heat exchanger backwards with hose (small amount of sand was in catch bucket), bleed the coolant for air (top vent plug) and added little coolant. The raw water flow is good, and the raw water is warm on exit so some heat exchanging is taking place.

So I'm only left with maybe the thermostat. I don't have any Kohler manuals that show the thermostat location and part number, so some help here would be greatly appreciated.

Thanks,

Mike
 
I had a Kohler that had an airlock and was solved by drilling a hole and adding a petcock.

Billy K.
 
I used an IR sensor and the heat exchanger center was about 180~190F, the top of the manifold the heat exchanger attaches to was ~180F. Exit water temp was ~95~100F. The generator temp sensor indicated 213F under load of 120VAC rb2@gr5t 25 amps, dropped back to 210F with load removed.
 
To me, you have 85 degree water going in, and 95 coming out, not much heat exchanging going on. Could be either the engine is not flowing coolant through the heat exchanger ( thermostat, water pump, blockage ) or the heat exchanger is plugged. Thermostat should be easy enough to change, it will have either a 160 or a 195 degree thermostat. It is located right next to the heat exchanger in a housing where the larger coolant hose connects. The top of it is sort of ball shaped and the coolant hose comes into the ball at about a 90 degree angle. If the hose still has the part number on it, look for hose 359949, it will be at the end of that hose. Kohler part number 254920 is the 160 and 249930 is the 195.........D..........

Keeping in mind IF I am looking at the right breakdown.........
 
The heat exchanger is bolted directly to the manifold, no coolant hoses to the heat exchanger I believe. The hoses are raw water to and from heat exchanger.
 
D Andrews,

Hopefully this will help me diagnose the problem.

Thanks so much,

Mike

Mike
 
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