I purchased an 01 Cherokee a couple of months ago and have been losing coolant like crazy ever since. I am filling up about every two weeks. I swapped out the thermostat and the thermostat housing, I had the head gasket changed when I purchased the Jeep, and I had a pressure test ran that showed up clean. I dont see any noticeable puddles under the jeep or any signs of it leaking underneath the jeep. I am in need of another opinion on what it could possible be and what I can do about it.

 

The head is cracked. Since this has been going on for a while, the oil is contaminated with coolant. Any lubricated part, especially the bearings, are damaged and possibly destroyed by now.

Your Cherokee was bad when you bought it. The previous owner knew this. This is why they sold it.

If it was mine, I would sell it now with disclosure. If you have a fair amount of money, time, and desire have the engine block assembly totally rebuilt IF it is rebuildable. Buy a brand new, aftermarket head from someone like Clearwater. Your old head is only good for a doorstop or boat anchor now.

 

First thing I did on it was change the oil, no milkshake in the oil also I had the head checked no crack was found. Im not getting a white smoke or weird smell from the exhaust and my floor is dry.

 

Your Jeep has a known factory casting flaw in the head. They typically crack between #3 and #4 valves.

Bench inspection on a cold head doesn't always reveal a crack. It can also be cracked internally where no one can see it.

 

By filling up with coolant every two weeks it should be quite noticeable.
Stupid question, but when you say you don't see any puddles to you mean after a drive, or have you let it sit while running and get up to full operating temp? Nothing in the engine bay at all?

 

I did pull the spark plugs and noticed very little green residue on them, but when I don't see any puddles it is after I drive

 

Easy. Coolant pressure test. Likely will confirm what firestorm said.

 

How was it checked?


A lot of people, including "mechanics", think they can look at a head and see a crack.

If your mechanic is one of those people, get another mechanic.

Many cracks are not visible, and only open up when hot and under pressure.

By the way, what firestorm said. You should do some tests to confirm it, but start deciding what you are going to do with a cracked head and possibly ruined engine.

 

There won't be any green residue on spark plugs in a healthy engine.

Your coolant isn't leaking on the ground. It is leaking into the engine and being burned. Some of it is getting into the oil.

 

Losing coolant before or after the head gasket replacement?

Hindsight=20/20 if the head was removed it should have just been replaced.
https://www.cylinder-heads.com/autom...er-heads/jeep/

 

If I read one of his early posts correctly, it lost coolant before and after head gasket replacement.

Therefore it is not a head gasket problem. It also is not the thermostat, water pump, or heater core.

Few mechanics are knowledgeable about the 0331 head cracking problem.

 

I had a coolant issue while driving in 100 degree weather and heavy stop and go traffic. My temp gage pegged all the way right, but after a short rest it dropped down to about 215. I intend to replace everything, for sake of having a clean system ('01, 136000 miles). I did NOT loose any coolant at all, not a drop. I have no signs of oil lose anywhere. I have had a ruff idle issues that comes and goes, can't figure this out. But, otherwise the jeep runs strong.

As I begin to do the coolant system, what else should I check for and do?