Coolant won’t get up to temp

[Tr3nt]

My truck won’t get up to temp. I thought it was the gauge or the sensor at first but after a long drive it went up a little, I will attach an image to show you the highest temperature I’ve seen.

 

[rzr6-4]

Sounds like a thermostat failed open.

 

[Ken226]

My truck won’t get up to temp. I thought it was the gauge or the sensor at first but after a long drive it went up a little, I will attach an image to show you the highest temperature I’ve seen. View attachment 558461

Looks like a 3rd gen instrument cluster. How many miles? and is it the original thermostat?

Like Rzr6-4 said, the thermostat failed in the stuck open position.

That's way better than if it fails in the closed position.

 

[Tr3nt]

Looks like a 3rd gen instrument cluster. How many miles? and is it the original thermostat?

Like Rzr6-4 said, the thermostat failed in the stuck open position.

That's way better than if it fails in the closed position.

It’s a 2000 Dodge ram 1500 with 108,000. I had just bought it and according to the title, the previous owner bought it at 97,000 miles. The previous owner said he has done no work to it besides general maintenance so I think it’s safe to assume it could be the original thermostat. I’m gonna go ahead and replace the thermostat and do a coolant flush. Thank you

 

[GTyankee]

If you call the dealership, the 2000 Rams use Mopar HOAT 5 year coolant

If i recall correctly .............

Valvoline makes Mopar HOAT 5 year Coolant
they also make a compatible HOAT Coolant, called Zerex G-05 HOAT

i am sure someone will either Verify or give me hell

 

[16 Cummins 4x4]

I just replaced the t-stat with a 190 deg one in my friend's 2000 5.9 gas pickup, and now he has normal full operating temperature, and his heater is putting out heat again.

 

[Mopar~Man]

I've got a 2001 Ram 5.2L, the instrument cluster photo in the first post looks like mine (but the 2 temp marks are 55 and 100 C b/c mine is Canadian model). I put in a 180 t-stat a couple years ago when I changed the water pump. My needle goes 1/3 of the way from the low-end of the range to the center. Sometimes I get a code for low engine temp. I would have thought the OP would have also gotten that code.

 

[GTyankee]

Did it work properly back in the summer weather ?