My 89 Cat 30 has been running hot. I have owned the boat for 9 years and it usually runs between 160 and 170 degrees. I have maintained my 3" heat exchanger by having it boiled out every two to three years. I replace my zincs every Spring. I also change my impeller every other year along with my hoses. I see plenty of water exiting the exhaust. I recently purchased an IR Thermometer and believe my temp gauge is reading correctly. I idle perfectly at 160-170, but rise up to 180 while under way. I just cleaned my raw water strainer and flushed the raw water through hull. I also replaced my thermostat (160 F). What can I check next? I realize the engine can run up to 180, but I am in salt water and have always run much cooler. Something is not right and I have no idea what it could be. Normally, when I run at 160 you can feel cool to warm exhaust water exiting. When it hits 170 you see some light white smoke and the exhaust water is hot to the touch.
Overheating
- Thread starter The chief
- Start date
- Status
Some time ago my 1993 Yanmar 3GM30F started over heating at cruising RPM. I finally traced it back to an old gasket on my strainer basket. I never saw a sign of leaking water but apparently it was allowing air to be drawn in at higher RPM's which decreased the water flow somewhat. I made my own cork/rubber gasket and it seems to have solved the problem. I love when it's a cheap fix.
I recently helped a friend with a Benneateau 44 resollve a similar overheating issue. It turned out to be corrosion in the thru hull for the water intake. We resolved it by using a coat hanger to scrape the "gunk" out. Since we've done that all is well. I hope it"s something simple like that.
- Status