Testing Resistance of Coolant Temp Sensor, are my values ok?


New member
Premium Member
Oct 7, 2018
Checking my temp sensor before I drop the engine back in.
2014 M8000 LTD

I boiled a pot of water, put in a thermometer and the sensor and took resistance readings as the temp dropped.
The image below shows the results.
What kind of tolerance with OHM would I expect to see? It's off by anywhere from 17-100 Ohm. Do you think the sensor is bad?
I replaced coolant pump seals but didn't do anything with the thermostat yet.
Any other ideas for overheating issues? maybe there's something clogged in the heat exchanger?
I replaced coolant, got air out of system, it still went hot.
There was a small pinhole leak in the oil pump inlet, what could that have done?

Arctic Cat parts were stupid to get this year, I didn't end up riding at all... I'd like to try to get at least one day in... once she's all back together, test my fixes.

Thanks for any help!



Old & slow

Well-known member
Lifetime Membership
Feb 18, 2017
Your numbers are consistently high that tells me the sensor is failed or at best inaccurate. This is based on your numbers being correct it is easy to be off if your thermometer is off a bit. By your numbers it would read cooler not hotter. I had a 14 and overheating was never a issue with mine. The air can be hard to remove from the coolant system. Replace the T stat or at least check it for proper operation.
Last edited:


Active member
Aug 4, 2012
Looks fine. Not knowing the intervals inbetween recordings at worse the sensor reads +2 Deg C on the higher end based on your numbers and the thermometer is accurate (tested against a known standard). Another thing to note is the element needs time to stabilize at temperature to give an accurate reading. In any amount i cant see being off by 2deg causing any problem.


Active member
Aug 4, 2012
Also thermisters are only accurate on a limited temperature range so that could be why the numbers fall apart on the very lower end. What do you mean by pin hole leak on the oil pump inlet? Out the leap hole on the bottom of the case? Generally these HO motors dont run hot even with limited surface area of the coolers. Either thermastat, problems with impeller, blockage, or trapped air would be your problem I would think.
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