T&T: Engine temperature

[David Marchand]

Sid:

The Seller and I are going through the exact same situation on an Island 
Packet Cat 35 with twin 27 hp Yanmars I am buying. Starboard engine runs 
perfectly at WOT, but port engine overheats. If the engine will not run at 
WOT without overheating, then you have a real problem. It may get worse and 
ultimately affect your cruising temperatures.

Some causes:

RW side restricted flow- thruhull fouled, strainer plugged, hoses collapsed, 
exhaust elbow plugged, impeller shreded.

RW/CW heat transfer- fouled RW cooler, pieces of impeller, zincs, scale.

Exhaust gas leak (blown gasket or worse) into the fresh water system adding 
heat.

Pure glycol in the fresh water system. Glycol has a much worse heat transfer 
coefficient than 50/50.

Go through a methodical diagnostic routine to get to the bottom of your 
problem. Don't replace parts, diagnose.

David