Universal 5411 Thermostat

[Todd Osborne]

Anyone had problems with their thermostat? My raw water cooled engine is running hot (180F) but remains steady at that temp. I put a water strainer with see through port just prior to the water pump. There is plenty of water flow through the system, although very little comes out the exhaust. I also backflushed the through hull valve intake & it seems fine. So all I can figure is either the thermostat is bad or my engine temp sensor is bad.

 

[patrick e. boole]

overheating

it is hard for that model engine to come up to operating temp because there is no heat exchanger and the water that got hot is nopt in the ocean with cold water taking its place. i would look to another source then the thermostat or just take it out and then see what happens. doesn't hurt to run it without. 180 degrees is nopt bad. diesel run better when they are hot.

 

[Bob Camarena]

Not Good in Salt Water

If you're operating in salt water, 180 is too hot. Salt will precipitate out and collect in your engine at about 160 degrees, eventually clogging the water passages. If you're only in fresh water, this may not be a problem although There may be other minerals in the water that may also precipitate out. The normal thermostat is 145 degrees and the operating temp should be no more than 150. Check your thermostat in a pan of water on the stove with a thermometer. It should trigger at 145. Patrick is right about 180 not being too hot for the engine to run at, except for the precipitation problem.