I had a question about overheating in my Cherokee. It’s run very well since 2014 through ~ 2023 with regular maintenance and all needs addressed promptly. Always running at 210F or less. Since a shop ~ 2023 it stays higher than 210F all the time after warmup and has heat spikes at the top of long hills or load shooting to 235 with check gauges. I turn it off with the hood up and then key on with three electric tans that cool it rapidly to 210 which seems impossible for it to climb fast and drop fast but has been reproduced and verified with a heat gun.
Thoughts?
Welcome to Car Talk…
Since this all started and has been a consistent issue since a shop visit 3 years ago, it might make sense to explain what was done to the vehicle and what the reason for the repair was back then…
Example, if a thermostat (t-stat) was replaced, was it due to overheating, or something else??
Questions:
What is the in-cabin vent temp when at normal operating temp??
Is the coolant full in the radiator and not just in the overflow tank??
Have you double-checked the temp at the t-stat vs. the live data ECT temp vs. the dash gauge?? They should all be moving together…
Have you checked for a blown head gasket?? block test??
Lots of possibilities, such as a restricted radiator, t-stat not opening all the way, bad fan clutch and/or electric fan(s) operation, radiator cap, air pocket, etc., etc.