Got the TJ in late summer ‘21 and flushed and changed out entire cooling system except fan clutch. Pretty much all Mopar parts and G05 coolant mix. It was running hot when I got it. Since then, it has pretty much run 195-200 anytime I am on the road and might get to 205-210 when doing traffic or slow speed off-road. All readings thru a Scangage.
This spring it started creeping up and my daughter was using it to commute to classes so I wasn’t getting to drive it much. She said every now and then a light would come on then go back off. I thought it was the heat soak miss and didn’t get excited. Then I drove it last week.
At low road speeds it would gradually get up to about 220. If you did 50-60, it would start climbing until it hit 260 and the light came on or you slowed down or stopped to cool off.
I tried another thermostat and then no thermostat. No difference.
I tried a new cap. No difference.
I flushed with Thermocure. No difference
Ran with clear distilled water only. No difference.
Saw no evidence of leaks and hitting 250 on only water said it was maintaining pressure.
Today I swapped in a Denso radiator. Couldn’t find a Mopar for less than $500+ (Denso $150).
Ran it with straight water and it went back to previous performance 195-200 at road speeds. I got the coolant back to correct mix and I am happy.
Question is: what is wrong with that Mopar radiator I pulled out? I want to get it fixed as a spare, but want to know what could have caused the issue. The coolant was in great shape (no rust and <2yrs old).
This spring it started creeping up and my daughter was using it to commute to classes so I wasn’t getting to drive it much. She said every now and then a light would come on then go back off. I thought it was the heat soak miss and didn’t get excited. Then I drove it last week.
At low road speeds it would gradually get up to about 220. If you did 50-60, it would start climbing until it hit 260 and the light came on or you slowed down or stopped to cool off.
I tried another thermostat and then no thermostat. No difference.
I tried a new cap. No difference.
I flushed with Thermocure. No difference
Ran with clear distilled water only. No difference.
Saw no evidence of leaks and hitting 250 on only water said it was maintaining pressure.
Today I swapped in a Denso radiator. Couldn’t find a Mopar for less than $500+ (Denso $150).
Ran it with straight water and it went back to previous performance 195-200 at road speeds. I got the coolant back to correct mix and I am happy.
Question is: what is wrong with that Mopar radiator I pulled out? I want to get it fixed as a spare, but want to know what could have caused the issue. The coolant was in great shape (no rust and <2yrs old).
