Over heating - new head - still hot
Greetings fellow Cherokee owners: I joined the forum a couple of years ago, but never really got around to posting. Sorry, life just got in the way.
Moving forward – I hate to beat this overheating issue to death, but I know there is a wealth of knowledge here with much experience that most certainly can lead me in the right direction.
2 weeks ago, I was headed out to do some hunting in my 2001 Jeep XJ / 4.0 / Automatic with 105,000 miles on the clock. I noticed before leaving the coolant reservoir was empty, so I added coolant. 1 hour into my road trip the check engine light came on and the Temp was above normal (215-218) and holding steady. I pulled over, let it set and as the motor cooled - coolant was extracted from the reservoir and back into the engine. I topped off the reservoir with water and proceeded down the road. I only made it about 1 mile and the temp starting climbing higher. I pulled over had it towed home.
Back home – I found the issue with the head casting (0331) on these model years. Looking thru the oil filler cap I could see a hair line crack between #3 and 4 runners. No doubt, head issue was my problem.
Ordered new head casting from Clearwater Heads: installed with new head bolts, Fel-Pro head gasket, new thermostat (I drill small weep holes in my thermostats to aid in the removal of trapped air), new water Pump and new radiator and cap. Engine deck was cleaned to a shinny luster. Heater core was checked and it flowed fine. Also, number 11 bolt was coated with Loctite 592. All torque sequences were as mandated by the FSM of this year. On a special note – the coolant was very dirty, almost like swamp water and there was sludge in the bottom of the reservoir tank. I am fanatical about maintenance on my vehicles, and coolant is changed every October in each of my trucks / cars along with a thorough check of all belts-hoses and components. So, this has just happened recently I would imagine.
Current: With everything back on, jeep started and ran fine….and it appeared that all was good. However, after about 20 minutes of road time the temp starts to climb above normal and the XJ is running hot. After taking it home and letting it cool, the coolant once again is drawn from the reservoir to replace what is missing in the engine. And it appears that there is oil in my radiator coolant when the cap is removed. But I do not see any evidence of coolant in the oil to include any of the valve-train you can see thru the filler cap.
So – to those here who are much smarter than I….what say you? Could it be that the head gasket for whatever reason did not seat on initial torque? Could the number 11 bolt be leaking (it is in the water jacket as I understand it). Is my block cracked? For those that suggest doing the head gasket again, do you suggest any one type over another and any type of adhesive? The Fel-Pro gasket I installed did not need any type of adhesive. I have seen on some of the forums that guys will use Permatex “cooper” regardless of what the instructions say. Is there a way to troubleshoot the head gasket separate from the block in terms of identifying where/how the leak is going?
Last thing – I did a pressure check of the cooling system with engine cold. Pressure was set at 15.5 psi and was left for one hour. There was no pressure loss during that time.
I welcome all suggestions…………