2013 Jeep Grand Cherokee overheated and cannot find the problem

[testdepth]

Daughter's friend showed up here yesterday with an overheating Jeep. Overflow bottle was bone dry. Upper and lower hoses were cool to the touch but engine block was hot. Radiator was also low on coolant.

Today we pressure tested the system at 16psi for 10 minutes and no leaks. Pressure never dropped.

We added antifreeze and bled the system until no air and it was full. The engine then ran at normal temp and then both hoses were hot as the thermostat had opened.

I can't think of any other reason it would have overheated? Normally it would be a leak, thermostat or water pump but all seem okay.

 

[Pro Carry 2]

Thermostat could have stuck closed. Does it have electric fan or belt drive. ?

 

[The Southern Gentlemen]

Daughter's friend showed up here yesterday with an overheating Jeep. Overflow bottle was bone dry. Upper and lower hoses were cool to the touch but engine block was hot. Radiator was also low on coolant.

Today we pressure tested the system at 16psi for 10 minutes and no leaks. Pressure never dropped.

We added antifreeze and bled the system until no air and it was full. The engine then ran at normal temp and then both hoses were hot as the thermostat had opened.

I can't think of any other reason it would have overheated? Normally it would be a leak, thermostat or water pump but all seem okay.

The exhaust could be clogged, I’ve had it happen to two different vehicles. First one was a Toyota taco the second one was my Jeep Wrangler. The internals of the cat come apart and cause the system to be blocked

 

[testdepth]

Thermostat could have stuck closed. Does it have electric fan or belt drive. ?

Electric fan and it was running.

 

[jaxyaks]

Blown Head Gasket?

 

[testdepth]

I believe he has a failing thermostat. The car sat idling and started to get hot. I grasped both hoses and both were not hot meaning the thermostat was not open even though the engine was starting to overheat.

 

[jaxyaks]

I believe he has a failing thermostat. The car sat idling and started to get hot. I grasped both hoses and both were not hot meaning the thermostat was not open even though the engine was starting to overheat.

Were you able to pin down the coolant loss issue

 

[Pro Carry 2]

Yep change the thermostat

 

[testdepth]

Were you able to pin down the coolant loss issue

I believe the thermostat stuck closed. After we bled the coolant system and purged the air out of it the thermostat finally opened.

 

[haole396]

If at idle, full operating temp, both upper and lower hoses are hot and hot air is being pulled through the electric fan, the t-stat is working. If it was stuck, or the water pump impeller was bad, one hose would be hot and the other cold. Check the oil level on level ground. If it’s clean/dark it’s ok. If it’s brown milky, that’s a head gasket.
I’d suggest getting some coolant U/V dye and add some to the radiator. Drive for a day or two and go over the engine compartment with a black light. If there’s an external leak, it’ll show up. And don’t forget to check the tailpipe (with the black light) just in case.
Hope this helps.