Overheating at idle (2006 Cherokee)

Overheal

I already checked under the hood and the radiator blower is a blowing, so, what are my other options for troubleshooting this problem? The water pump was replaced new professionally about 4 years ago so I don’t think it’s that, and also figured I would have a warning indicator or code if that were the case? Need to know how to dodge another expensive repair.

biko

Possibly there isn't enough coolant in the system.
Try parking facing up in an steep incline, open the radiator cap (it will be very hot) and let car run to push out all trapped air in the system.
You can also give the hoses a squeeze but be careful around moving parts.

Tea drinker

Could be blocked/sticking thermostat, or a blockage internally in the radiator. Even mud caked on the rad externally can cause issues. (a power wash can help there) Are the water pipes hot on the both sides of the radiator.
The American stuff can have 2 speed radiator blowers and if the high speed doesn't engage it can cause issues but I'd expect that as more of a summer / hard driving issue than idle.

Overheal

Tea drinker wrote: »

Could be blocked/sticking thermostat, or a blockage internally in the radiator. Even mud caked on the rad externally can cause issues. (a power wash can help there) Are the water pipes hot on the both sides of the radiator.
The American stuff can have 2 speed radiator blowers and if the high speed doesn't engage it can cause issues but I'd expect that as more of a summer / hard driving issue than idle.

Yeah the car has sat pretty much 99.9% of the pandemic, and I last checked on the car in July, when it was hottest, I was much more worried with battery maintenance but I thought the heating was just a symptom of the hot day. Knew something was off when it was doing it while chilly out this week. Didn't know that about the fan speeds but I don't think that ended up being the case. Rad's clean aside from a few specks of gravel.

biko wrote: »

Possibly there isn't enough coolant in the system.
Try parking facing up in an steep incline, open the radiator cap (it will be very hot) and let car run to push out all trapped air in the system.
You can also give the hoses a squeeze but be careful around moving parts.

That was the trick. Had topped off the reservoir before I went for a drive to said hill and I didn't think I would make it there, it was in the red! But, when I bled the gasket head it started rumbling up in the reservoir too, like a clogged toilet it gurgled up a bunch of crusty old coolant into the reservoir. It settled back down to about 3/4 of the gage, went and got another gallon of coolant and filled the now-empty reservoir and it's back down comfortable left of center on gage. Thanks for the tip! I'd say it's due for a flush now.

biko

Sound, happy to help.