third coast

I want to focus on your mention of "using a block tester with the yellow liquid". The fluid should start out blue and will change to yellow or a greenish color if exposed to CO2. Be sure the tester is cleaned thoroughly with clean water and no contaminated fluid remains before performing the test.

FewScrewsloose

Thank you all again for the help so far.

So, you are correct, the liquid was blue and was supposed to change to the yellow or green color. It in fact did not change at all.

I was able to confirm that it also is in fact the factory "0331" head.

This is what I did last night:
I had ordered over the weekend another spill proof radiator fill funnel so that the coolant would be higher than the upper radiator hose to help with flushing out any air in the system. I let this run and cool down several times over a 2 hour time frame and then let it run with the funnel still attached, no radiator cap obviously, for 15-20 minutes. The Jeep did not overheat and stayed just below 210. No other bubbles in the coolant in the funnel and the thermostat was opening and closing as you could see the coolant and the temp gage cycling. My plan tonight after work is to see if reinstalling the radiator cap "new one" will still cause it yet again to overheat. Fingers crossed.

Could this just have been a matter over too much air in the system still? I will update more findings later tonight or tomorrow after digging in as mentioned.

third coast

It could have been just due to air. It would be unusually good luck if that is the end of the issues. As an FYI, from the factory Chrysler vacuumed filled the cooling system to speed the process and ensure all the air was removed.

I have replaced a cracked 0331 head thus I have a bit of experience in this area. If it was me I would have an oil sample analyzed for the presence of antifreeze in the oil. That is how I discoverd a cracked 0331 head very early before other symptoms showed or damage was done. For about $30 Blackstone (www.blackstone-labs.com) does a good job in detecting even small amounts of antifreeze in the oil (there should be none), plus identifying excessive wear metals, a sign of other problems that should not be ignored if reliability and a decent life is desired from this engine. To me this is the easiest way to get a better idea if there is a cracked head, head gasket or related issues. If you have not already changed the oil drain it and collect a sample mid drain following the labs instructions. If you have already changed the oil I would get some miles on it, at least 500 miles with a number of heat up and cool down cycles, then have an oil sample analyzed. A cracked 0331 head typically puts antifreeze into the oil and this is the best way to detect even a minor crack. If you allow antifreeze to continue to contaminate the oil it will accelerate bearing wear and eventually kill the engine.

I would not replace the 0331 head if no problems can be determined but I would try to avoid any future overheating or similar abuse. As I mentioned previously these heads do not like to be overheated.

For future refference getting a Cherokee more than bumper deep in water is also not great for the engine computer and other components and connections that can suffer from corrosion.

FewScrewsloose

Ok Guys,

I have had very little time since we had last posted to actually do much work on the girlfriends Jeep. Below is what I did get done and I am still open to suggestions.

Topped off cooling system and bleed any air
Pressure tested radiator cap for function- works
Verified that the head is indeed a 0331 head by casting marks
Upgraded alternator to a dodge 135amp with mounting bracket modification as the alternator she had was cracked and frozen solid
Verified engine oil level was full and showed no signs of coolant contamination visually ( no oil analysis yet)

So, I installed radiator cap and a fully charged battery (as her jeep also is showing signs of a major electrical draw as well while no key in ignition-will be looking into this at some point as well)
After installing radiator cap and battery I fired it up. It ran but not well. Had a slight stumble to it and with very slight load on the throttle it had what sounded like piston slap or a knock from the bottom end rear half of the engine.
Upon letting it warm up, smoke/steam showed just to the right of the oil fill cap alongside the cylinder head. I attempted to find the source but this engine has many many oil leaks from the valve cover all the way down to a weeping oil pan due to rust. Anyways, I had started to suspect that this steam/smoke may in fact be coolant burning due to a slightly sweet smell to it. Again, at the time I was unable to verify the source of this smoke/steam.

After letting it warm up to 210-215 the heater core hoses were barely warm and the radiator began to spew coolant from the cap. Shut it down and let it cool.

So, the girlfriend wants to just replace the whole motor again ($350-$400) from the same place she bought this exact engine from a year ago. They have a 90 day warranty on their engines.

I suggested a full rebuild of her current engine with the upgraded head per this thread recommendations and I could machine the rest of the engine at work (work at a machine shop) but that could be a 2-4 week turnaround waiting on parts and such as opposed to her having a used engine by the weekend dropped in the driveway to be swapped out over the weekend.

Looking for any thoughts, ides, anything that I may be overlooking, etc..

Thanks in advance for all the help guys!

Dave51

IMO you should start your own thread as some members with helpful information might be bypassing zombie threads.

I think it's a little aggressive to be replacing the engine when you don't know what the problem is.

For that matter, it might be a little aggressive replacing the 0331 head when you don't even know if it's cracked or not (I got an 0331. I'm not crazy about it, but it works).

More testing. Any engine codes? What's the compression? Is the exhaust and/or cats clogged? Is the thermostat stuck? Is the water pump working?