Thermostat MXP-25

[newpbs]

I am concerned that my diesel in running a little on the cool side. My plan is to do some trouble shooting this weekend. The gauge might not be reading correctly, so my sender may need to be replaced.

It seems likely that my thermostat i not closing completely. I'm not sure if it has ever been replaced. I would like to know if my Universal engine will take an automotive thermostat. Photos that I have seen look like the same type of thermostat that I would put in my car.

It would be great if I could pick up a thermostat at the local auto parts place. Also, a replacement thermostat online is over $55.

Paul

[newpbs]

I'm surprised at the lack of response. Doesn't anyone know if an automotive thermostat will fit into a Universal MXP-25 diesel?

[Stu Jackson]

Patience, patience...

No, I don't think an auto thermostat will fit, 'cuz while they work the same way and look identical, the HOUSING is different.

Rather than pay marine prices, however, go to a Kubota tractor dealer and save big bucks, buy three for the price of one!

Reduced engine heat to hot water heater & Kubota dealers in CA

[newpbs]

Thanks for the response. My local Kubota dealer does not stock the thermostat and ordering one would have set me back about a week. Their price would have been $34.

Good news is that a nearby independent marine supplier had one on hand ($75).

Also good news is that replacing the thermostat seems to have fixed my problem.

Happy Sailing.

[ccriders]

newpbs,
I was hoping for more info from your initial request. I previously posted a question about how to test the performance of the sending unit and the guage separately to determine if they were working properly. The few responses I received did not help me. Maybe I'm too dense to understand what I was told. I too think my engine (Atomic 4) is running cold but don't know what temperature it is running. Did you just change out the thermostat? What did the guage indicate before and after?
Thanks,
John

[newpbs]

John,

I did replace the thermostat. With the old stat we were running at 140F. The new stat pushes our temp to 165F on the gauge. We also noticed that our hot water began to work again. I suspected a link between the hot water not working and the lower engine temp. Seems that the water just wasn't being forced through the hot water tank with the weaker stat.

We had an Atomic 4 on my dad's boat. When we suspected that it wasn't running at the right temp we would check it by touch. After running it for 15 years we knew that engine that well. I don't remember what temp. the thermostat for that engine was, but I do know that we could get a replacement at the local auto store.

For trouble shooting I did find some resistance values for the temperature sending unit. My Universal MXP-25 is different from your A4 but the sender values might be the same.

Temp F Ohms

80............. 652
100........... 405
120 ...........270
140........... 184
160 ...........135
180............ 95
200............ 76
210 ............69

Good Luck,

Paul

[tomhuntdmd]

One of my projects last weekend was to establish a baseline set of temperature reading on my Yanmar 75 as per Mainsail's instructions here: Engine Temp Monitoring & Over Heating Baseline Assessment Photo Gallery by Compass Marine at pbase.com .

One of the best instruments you can have on your boat (or at home) is a laser thermometer. I am not always big on Harbor Freight electronic tools, but this one Non-Contact Infrared Laser Thermometer has worked well for me. As others have posted, you can also use it to prevent "shrinkage" when jumping into the ocean, and to find the coldest beer in the fridge!

Tom