Picked up a 2001 Cherokee back in September. After a month in a half of owning the XJ we found out it had a cracked head. Took it to a local shop and it's all good now. Since then I've installed a Rough Country 3in AAL Kit. Very happy with the ride quality so far. As of yesterday I had a set of 31s mounted to some black Cragars that my wife got me for Christmas. I love how it looks now!


Issue: A few days after having the head replaced I noticed I was leaking coolant. Upon further inspection it was leaking from under the radiator cap. I drove it a few weeks and noticed my heat wasn't working any more. I took it to the shop yesterday, and they said they think the cap is loose. I went to autozone bought a new cap, but still have the leak. We noticed that the plastic elbow that the radiator cap mounts to is worn, possibly keeping it from sealing correctly. Has anyone seen this before? If so what was the fix? Thanks again!

Close up pic of the wheels.

I have heard that cheap aftermarket radiators sometimes can have that problem. Be careful the leak your chasing down is probably what caused the head to crack.

I thought the cracked head was due to a bad casting? It seems that the cap just won't seal cause it to release the pressure from under the cap and not send to to the overflow....?

That truck had the 0331 head. Those don't need a reason to crack. They just do it on their own.

That's kind of what I was thinking about the head. When you look at the plastic elbow that the radiator cap mounts too it looks worn, most likely from years of opening and closing the cap. I believe this is preventing my cap from fully sealing.....

But a reason will encourage them.

Those are so ornery that I think if you gave them a reason to crack, they'd refuse to do it just to spite you.

What are other potential reasons for it to lose coolant from under the cap, besides the cap not sealing correctly?

It could be cracked. You could be buying a cap rated for the wrong pressure. Or it could just be worn out and ready to be replaced. Radiators are relatively cheap and easy to replace.

That doesn't address your entire problem, though. You mentioned that you don't have any heat. Even if your radiator is leaking, coolant should still be circulating through the heater core to give you cabin heat. When was the last time your heater core was backflushed? If you had a cracked head and were boiling coolant within the system, the heater core is probably full of that nasty reddish brown sludge.

When they replaced the head they did a full flush of the system. I had heat up until last Saturday. When I was at the shop they put more coolant in, and I do have heat now. The new cap that I put on is a factory replacement 16.

Cap not seating correctly can either be the cap itself, or the spout on the radiator. How does it look? You said it's worn. Do you have a pic? Is there any crust or scale on the cap or spout?

Try a different brand of rad cap, they aren't that expensive. Other than that, without seeing the spout, you may just want to replace the radiator. Again, not terribly expensive. You just spent a some coin on a new head, so protect your investment. If your gonna be in there, check your water pump, thermostat, and all hoses. All these are relatively inexpensive, and a must to keep your cooling system running properly.

Sorry no pic of the elbow, I'll try to post one tomorrow when there is some daylight.

No problem, update with pics when you can. Your jeep looks alot like mine did when I first got it. Here it is now:

A leaking cap will cause it to over heat.

Strange that the stock radiator would be that worn out but like already stated try another cap. If that doesn't work and your sure its coming from there then your probably going to have to replace the radiator.

The older heads could withstand the heat better but if the 0331 head was that bad it would of been recalled. I drove mine fine in 110+ degree weather with the a/c on when I lived in New Mexico but then again my cooling system works correctly.