Possible Head Gasket Issue

[AUBoggs]

I've been chasing air in the cooling system most of the year. Replaced thermostat, water pump, coolant temp sensor, and the overflow bottle and hose. I've burped the system each time and, ran within spec temps after each repair. But, after a while I'd get the same erratic temperature , would smell coolant, and would have air in the cooling system. Yesterday I did a block test and, the fluid went from blue to yellow. Double checked the blue fluid by repeating the test against exhaust from the tailpipe and, same result. I'm not losing coolant and, see no steam vapor coming from the tailpipe. Has anyone had or heard of a similar issue where coolant isn't leaking from the system yet, the block test indicates a head issue?

 

[tJKrider]

Guessing here, but what about the heater core? Maybe that is about to completely sell the farm and your seeing occasional leading indicators.

 

[AUBoggs]

I don't have any of the symptoms of the core failing inside the Jeep. Heat blows hot, no coolant inside the vehicle, and the coolant smell I get is up by the overflow bottle. I've confirmed the overflow has gotten high enough to push coolant out of the spout. Good suggestion, I'll do some additional research.

 

[tJKrider]

I don't have any of the symptoms of the core failing inside the Jeep. Heat blows hot, no coolant inside the vehicle, and the coolant smell I get is up by the overflow bottle. I've confirmed the overflow has gotten high enough to push coolant out of the spout. Good suggestion, I'll do some additional research.

Makes sense. When you said you smelled coolant I thought you meant from inside the cabin.

 

[AUBoggs]

Makes sense. When you said you smelled coolant I thought you meant from inside the cabin.

Yeah, I could've been more descriptive. It's still under warranty so, it should be covered if it's a head or a head gasket. Appreciate the response.

 

[Speartip]

I don't have any of the symptoms of the core failing inside the Jeep. Heat blows hot, no coolant inside the vehicle, and the coolant smell I get is up by the overflow bottle. I've confirmed the overflow has gotten high enough to push coolant out of the spout. Good suggestion, I'll do some additional research.

If it’s filling up resevoir/overflow good chance it’s the head gasket .
My 2008 would do that if pushed on the hwy. I would reg suck out overflow with a Turkey Bastor and put bk in rad .
Had the head gaskets replaced , heads machined flat and solved the issues .