Universal M15 temperature

[Gary G]

I have a 1983 E28+ equipped with a Universal M-15 diesel that insists on running hotter than spec (which is 150 degrees). The engine is set up with a closed coolant system rather than use raw seawater for direct cooling. Would this "modification" cause the engine to run hotter (say 175 degrees) that the version cooled by seawater alone? I had the impellers replaced and the cooling lines of the closed system cleaned but it made little difference. Water seems to squirt out the exhaust port ok. Do I need to add this to my list of things to worry about?

Gary G
s/v Imi Loa (E 28+)

 

[Sean Engle]

Run Your Cooling System...

If it's not running to spec, then start at the raw water intake (ensure that it's clear and not sized down with growth or trash) and work your way through the system. If water is passing, and it's still running hot, then you're not removing enough heat from the system (aka - an insufficient quantity of water is passing through the system).

If your raw water pump is ok, and your raw and fresh water hoses are ok (and I'm assuming here that you have no air trapped in your system), then you may wish to look at your heat exchanger. I know my engine's running temperature began to creep up; in the end, the exchanger crapped out (rotted out). Once it was replaced, the engine ran very, very cool.

How old is the exchanger?


//sse

 

[stbdtack]

Eng temp

A FWC engine usually runs around 180 deg with 195 being the normal upper limit on many engines. The 150 deg spec is for raw water cooled engines and keeps the salt water from forming crystals that clog the cooling passages.
If your engine is Fresh Water Cooled and running at 175 then its a good thing. It will run more efficiently at the higher temp than an engine at the 150 deg spec. The thermostat in the system should regulate the temp if all is running correctly.

My older Perkins usually runs about 195 under load. Has 5000+ hours and still going strong. The book says 195 is OK.

I wouldnt be concerned about your motor....