A couple quick questions, about the cooling system?

[KennethS]

BEFORE pulling the head, are you absolutely sure you don't just have a leak somewhere?

I agree with this. And if you really think the head gasket is blown or the head is cracked, go to the local auto parts store and rent their coolant test kit to check for exhaust gases in the cooling system. Cheap and easy check that could prevent a lot of unnecessary work and expense.

 

[Jmac00]

btw, there is NO leak from the heater core. no condensation on the windshield.

Like i said, we ran for a couple hours in Phoenix stop-n-go traffic yesterday and the jeep ran fine, no over heating, and we even ran the a/c.

 

[Jmac00]

ok, I did a pressure test on the system.

at first I ran the test at 10psi, because the cap I have is a generic thing with no psi rating. then just for the fun of it, I ran the pressure up to 14psi, and it held for 5 minutes? Im guessing its NOT a head gasket issue.
Tomorrow Im doing a flush and refill,

 

[TJ4Jim]

ok, I did a pressure test on the system.

at first I ran the test at 10psi, because the cap I have is a generic thing with no psi rating. then just for the fun of it, I ran the pressure up to 14psi, and it held for 5 minutes? Im guessing its NOT a head gasket issue.
Tomorrow Im doing a flush and refill,

You really need to be up at the 18lb system operating pressure for a thorough test, there is a lot of potential energy in 4psi.

 

[Jmac00]

when doing a complete flush of the cooling system, do I need to flush the heater core separately, or can I do it all at once by running the engine and letting the stat open?

 

[TJ4Jim]

when doing a complete flush of the cooling system, do I need to flush the heater core separately, or can I do it all at once by running the engine and letting the stat open?

It can be flushed with a system flush but many choose to rig up a separate flush with a garden hose as the cores tend to trap sediment. Also many including me will run distilled water for a few days then dump and re-fill as long as temps remain above freezing.