I just had a diesel mechanic install a high temp and low oil pressure alarm and install a new thermostat, since the original was causing overheat problems. He installed a thermostat that operated at 140 degrees. Is this to low of a temp setting. I heard diesels like to run hotter.And if it is to low what are the problems if I use it? Thanks for any advise.
Proper thermostat for Universal M25
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Kubota makes two thermostats, 160 and 180. In 13 years I have never heard of a 140 thermostat for an M25. Either will work just fine.
http://c34.org/bbs/index.php/topic,3133.0.html
Also sounds odd to say the thermostat was causing overheat issues, since the only things I can think of that do that are: HX, rw pump impeller, clogged rw inlet.
http://c34.org/bbs/index.php/topic,3133.0.html
Also sounds odd to say the thermostat was causing overheat issues, since the only things I can think of that do that are: HX, rw pump impeller, clogged rw inlet.
If you are running raw salt water for cooling then
It has to be no higher than 143 degrees to prevent salt build up in the water jacket. Even raw fresh water should be no higher than 160.
It has to be no higher than 143 degrees to prevent salt build up in the water jacket. Even raw fresh water should be no higher than 160.
It may have been a 160 degree thermostat, I checked with a thermometer and it was working at around 140. I was there when the old thermostat caused the new high temp alarm to go off. But looking back its possible the mechanic didn't install enough coolant after the work was completed. Either way it has a new thermostat.
Sticking maybe? My old Jag developed a heating problem. Starting with simple first, I checked the pressure cap, belt tension and hoses. Then I pulled the thermostat and found that it was not opening all the way. You could see some scoring on the shaft where it would hang up. So, it opened enough to keep the engine happy for cooler weather and short trips but couldn't produce enough flow for low speed hot weather, or high speed hot weather.
There are lots of marine engines out there running 180 stats especially engines operated in cold water. Our Westebeke has over 3200 hours of a 180F stat and runs better than many engines with just 200 hours. Universal offers or offered both a 160F and 180F stat for the M-25 but not a 140 that I know of.
With a RWC engine then a 140F is appropriate to prevent salt precip but an M-25 is a FWC engine and salt precip is a non-issue. With an HX seawater temp is only ever rising 15-25 degrees and you're well below the temp at which salt begins to precipitate out of the water. I ran both 180's and 160's in M-25's and they seem to run fine with either but burned off internal condensation faster with the 180F stat. 140F is out of spec for a FWC M-25 and I don't believe they ever built that engine in a RWC version..
If you still have the original 2" HX then I'd stick with a 160F. If your HX has been upgraded to the 3" model and you're in cooler water then a 180F is perfectly fine and you'll burn off start up condensation faster. With short engine runs getting that condensation out of the engine as soon as possible is a good thing..
I second what Stu and Mainesail said. I run a 180 in my Universal and every other Universal that I know run the same.
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