MooreALX

February, two weeks after buying my XJ from a used car delership, my engine overheats, and I crack the head (its one of the infamous '00s). Even thought I bought "As is", the dealer agrees to pay for labor if I pay for parts. I only agreed to take it somewhere because it was the middle of the school year and there wasn't time to do it myself. I got a new head, and the mechanic claims it was the radiator, so he replaces that as well. He seemed to do sloppy work so I'm never taking it back there again.

Off and on over the past few months, it sprays coolent out of the radiator cap. So far we've replaced the radiator, thermostat, radiator cap, and the hose that connects the radiator to the resavoir. I've also removed and inspected the water pump. Now its getting to the point that pretty much every drive even a minute or two will be enough to make it start spraying. I have the dumb idiot lights, so I don't know the temperature of the engine.

It looks to me like its pulling coolant from the reservoir fine, but when it trys to put some back, it can't, and just has to spray it out the cap. Please help, I've tried everything I can think of.

brutalxj

Lift the hood open a beer or 6 let it run and see what is going on. If it is coming from the cap you need a new one 13psi is what Jeep used. Or it could be coming out close to the cap through a crack in the radiator.

Bustedback

It could be a blown head gasket. If the guy did sloppy work he may not have torqued the head bolts properly or clean up the block as well as he could have been.

MooreALX

I'll watch it over my lunch break. Autozone sold me this cap last week. It looks like it's 16psi, but wouldn't the higher pressure rating make this this issue even less likely? I sure hope I don't have to redo my head gasket.

BuckB91XJ

You have a blockage somewhere in the system. Could be stuck T-stat, crud, rust or air. I'm guessing in the motor since you say you replaced the radiator.

BuckB91XJ

Did you do a complete flush of the system when you swapped the radiator? If you didn't, you need to.

MooreALX

I realize this is bringing up an old thread, but I figured I post the resolution in case someone else has the same problem in the future.

The new radiator was plastic where the radiator cap screws on, which apparently prevented the cap from tightening down properly. Simply bending the two tabs on the cap up to make it tighter solved the issue!

Thanks for all your help guys!

djb383

I hope they gave u the correct cap.....shouldn't have to bend any tabs. The way the rad cap fits the rad (bending tabs) can effect the pressure release point/mechanism that's designed into the rad cap. It would be worth verifying the correct cap as it is a 2 way valve and must function correctly in order for the coolant recovery system to function correctly.

elgrandejuan

Has anyone figured out the coolant coming out the cap? I have the same problem. I have replaced the radiator twice along with 2 new caps (advance auto swapped me out no charge). It will draw coolant from the reservoir just like MooreALX. Any help would be greatly appreciated.

ZINGGG

Like said above, you probably have a blockage somewhere. A stuck thermostat or a nice rusted up passageway. What color is your coolant?

elgrandejuan

It's new, yellowish so far. Thanks for the help. I've never had so many coolant problems on a vehicle. I also have replaced the 4 way heater hose valve & yes it's hooked up correctly.

djb383

Rad cap should seal tight to the top of the neck of the rad thus preventing coolant escaping the rad and onto the ground. Rad cap gasket is bad, neck of rad is bad, or both, or wrong cap.

cruiser54

I had to mod the cap on my buddy's 99 to fix it.

Bbasso

I had this very same problem.
I went through 4 autozone rad caps, each of them leaked.
I bought one from napa, same thing.
I gave in and spent the $ at the Jeep dealer.
The differences between the caps were amazing! both 16PSI but the construction was worlds apart.

Before you spend er waste your $ try a OE (Jeep) rad cap.

I no longer have any leaks or worries.

cruiser54

Interesting. Thanks. My buddy's cap was a Stant from Napa and I had to mod it.

Geez. Not only am I not a fan of stant stats after changing three of them, I will add their radiator caps to my BANNED list.