[rubicritter]

I'm having a bit of heating issue. Here's the details:

03 rubicon, 100K miles
heat seems to cut out when the jeep is at idle.
heat is fine while driving.
heat still gets very hot like it always has.
engine temp gauge seems to be normal.

some have suggested this is a tstat issue since the heat is still hot (suggesting it's not the core). but others said that if it was the tstat, the engine would overheat or not heat up much.

anyone have any suggestions? thanks!

 

[Topless Rubi]

the gauge in the instrument cluster is a simple idiot light with fake movement if I remember correctly. To know the exact temperature you should use a actual gauge/sensor.

john

 

[gregert12]

The thermostat is a cheap part, I would change it first.


How is the water pump? Is it grinding at all?

Are your inlet and outlet hoses heating up normally or too much when at idle? If so, it is your heater core.

Have you recently drained the radiator? There may be an air pocket. Is it gurgling?

Are there any vacuum leaks? The blend door maybe sticking. Do the other fan speed work?

 

[rubicritter]

no grinding that i can hear.

all fan speeds work. maybe i wasn't clear. the heat cuts out, so the air becomes cool. it's not that the fan stops blowing.

have not drained the radiator. coolant was changed 2 years ago.

i'm not really that mechanical so i haven't checked any hoses.

 

[Eric]

not to point out the obvious, but check the coolant level in the radiator and the over flow bottle 1/2 full

 

[gregert12]

not to point out the obvious, but check the coolant level in the radiator and the over flow bottle 1/2 full

and what color/are there any contaminants in the radiator's fluids?

 

[texasrubi]

the gauge in the instrument cluster is a simple idiot light with fake movement if I remember correctly. To know the exact temperature you should use a actual gauge/sensor.

john

the Oil Pressure guage is the fancy idiot light.

the Water Temp guage is a real guage, it's spot on wth my ScanGuage

but mine is an 04, think they are all the same tho

 

[rubicritter]

the radiator has juice up to the top. the overfill bottle is not half full, but there is fluid in it because i can see the reflection at the bottom. it basically has no color. if anything, it's the pale orange-ish stuff. it's the correct fluid though; i checked it all out before i bought it two years ago.

 

[rubicritter]

update:

I put more coolant into the overflow tank so that it is up to the full line marked on the tank. I have not had the heat problem for two days now. It's hard to believe this was the problem, but I will go with it for now and update again if necessary. I hope this is the fix, even though I feel a bit dumb for not having checked this out before posting.