2012 Journey Strange overheating issues.

[Kilgorq]

I am working on my daughter's 2012 journey, and I am leaning to a cracked head or blown head gasket.

 

It is a V6.

 

It has been overheating on her for a while now. She had the radiator and thermostat replaced. We replaced the oil cooler since it was pouring oil out of it.

Here is what I have done.

 

Flushed the cooling system to get rid of the oil in it from the broken oil cooler.

Filled with water.

Purged the cooling system using the purge valve on the top of the thermostat housing.

Let it idle for about 20 minutes. Then revved it to 3K rpm to warm it up. With Front and rear heaters on.

Verified fans and they are working fine.

Took it for a test drive. After About 10 minutes, it started overheating.

Repeated flush, fill, and purge.

Took it for a test drive again and got the same results.

Ran a pressure test and found that the upper radiator hose was leaking at the clamp.

Replaced the clamp and re-ran the pressure test. It held at 18psi for an hour.

Tested the cap and it is good.

Repeated flush, fill, and purge.

Took it for a test drive again, This time it ran well for about 20 minutes. I was accelerating pretty hard and all of a sudden it lost power. Not 15 seconds after this, the temperature started climbing again.

I let it cool down and topped off the cooling system again.

I repeated the pressure test, and it all checked out fine.

 

The sudden loss of power followed by almost instant heat increase make me think head issues. But I am not familiar with this car and would like to hear any other theories. Or things to try.