Correct coolant temperature

[kidzdad01]

My mp8 in my 2014 Pinnacle runs 170degrees no matter what the outside temp is. That seems a bit low to me. Anyone know what the correct temp should be?

[JoeH]

There's probably a few temp choices when buying a thermostat. Cars are like that, you can choose 175°, 180, 185... No idea what choices Molvo gives you. If you're down south maybe the factory put in a cooler thermostat because you deal with hotter temps than we do up north. 180 is what I like my trucks to run at, but everything I have is '95 and older. My 95 RD pushes 200 a lot. Need to clean the radiator and intercooler.

[kidzdad01]

Thanks

[MACKS]

On 2/26/2019 at 9:08 PM, JoeH said:

There's probably a few temp choices when buying a thermostat. Cars are like that, you can choose 175°, 180, 185... No idea what choices Molvo gives you. If you're down south maybe the factory put in a cooler thermostat because you deal with hotter temps than we do up north. 180 is what I like my trucks to run at, but everything I have is '95 and older. My 95 RD pushes 200 a lot. Need to clean the radiator and intercooler.

I don't know about new trucks but was told by a very good mechanic the older engines will run 90 degrees above ambient temperature.

[Rob]

90 degrees above ambient used to be taught as optimum for a working engine when everything was iron. I'm not sure about newer composite engines being the same. In reality your coolant thermostat(s) should modulate to maintain coolant operating temperature someplace close to their rating. A cold engine is usually resultant of the thermostat not partially closing or restricting coolant flow in the system. A hot engine is usually lack of air flow through the heat exchanger, (radiator) or a restricted coolant flow. 180-190 degrees is about the target to ensure good fuel burn and efficiency from my experience.