Jake DeBroux

Hello everyone my xj has always been a little hot but recently it has been overheating when I stop driving and park. It will stay within operating temp while driving and get a little hot when on traffic but when I park I steam and leak from the radiator cap. I have replaced my water pump, thermostat, e fan, radiator cap (2 times), did a cooling system flush and replaced a couple of hoses, I also had my head gasket tested for leaks and i don’t have any. I am thinking about getting a 3 fan setup but not sure if it will solve my problem because it doesn’t overheat until turned off. Any suggestions on how to fix this thanks.

TRCM

What year ? 4 cyl or 6 cyl ?

You replaced the cap...but what pressure cap did you get ?

If it's boiling out of the cap, what about the reservoir ?

What do you call 'operating range' ??

Are you sure the cap is sealing ?.Buddy of mine found a small ding/bend in the sealing area of the neck and that was not letting the cap seal or hold pressure on his..

Are you using 50/50 water & antifreeze ?

Are you sure there is no air in the system ? Did the t-stats have a hole in the flange for air to burp out ?

More fans won't help.....does your e-fan come on when the engine is hot ? does it come on with the ac ? have you replaced the fan clutch ? these won't help with the engine off, but they will help cool it off more before the engine is turned off

Jake DeBroux

2001 6cyl, not sure what the cap pressure is it’s just the one they gave me at o rileys. By operating temp I meant 207 to 213 and as far as I know the cap is sealing only leaks when I turn it off after a drive, I use 50/50 green and yes the t-stat had a hole for air to release and my Efan does not turn on with ac and idk if it does when engine is hot

third coast

Electric fan should come on automatically with AC on. You may have a fan issue, fan relay issue, etc. You will find several fan troubleshooting on this forum and on others.

Jake DeBroux

Would that explain why it doesn’t over heat when running but does when parked

TRCM

If the cap isn't sealing correctly, it probably wont do anything until the engine is shut off and flow goes away...that's when it gets the hottest.

205-215 is pretty much normal for these engines....I run a 16 lb cap....I also run the fan clutch for the 4 cyl engine, as it's a heavier duty version than the 6 cyl

If your e-fan doesn't kick on with the ac, you have other issues.......check the fuses & relay for the e-fan....if ain't coming on with the a/c, it probably won't come on due to engine temp either

Also make sure you have a full fan shroud.....

You can disconnect the senor at the t-stat housing with the engine running and see if the fan turns on (it should), but it will give you an engine code....if you don't have a way to clear it, it may take a few engine running cycles to go away on its own

.

Jake DeBroux

It turned on whiteout the sensor what does that mean? Do I need a new sensor? I will go get cap as well and the 4 cyl fan clutch

Jake DeBroux

I’ll get a new cap today as well as the fan clutch. The fan did turn on with the sensor removed what does That mean

fb97xj1

That means the fan is working. When there is no signal from the sensor to tell the PCM what the engine temp is, the PCM turns the fan on to keep the engine from overheating.

Jake DeBroux

So replace the sensor?

TRCM

If the fan came on when you disconnected the sensor, then it tells you:
1) the fan does work
2) the fuses & relay are fine
3) the fan does as it should in those conditions

Now, you need to find out why it doesn't come on with the A/C

Fan clutch -> get it at NAPA...#272310.............be careful installing it, as it is thicker.....I put a sheet of cardboard against the radiator so I didn't risk nicking any tubes

Understand, even tho you flushed your radiator, it may still be the problem if it has too many tubes clogged.......rock auto has some good ones for less than $100, or the one I run for 250 or so....(all metal)

Make sure you vent the system extremely well, and it may take several outings for it to finish venting via the hole in the t-stat flange

Get an IR temp meter and check your temps at the t-stat housing to see what the temp is there versus what the gauge reading says it is


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Randy Bobani

The best cooling mod for the 4L Cherokee is a manual override switch for the E Fan. I just turn it on and leave it on. You can even leave it on when you stop to pump gas or a few minutes after a long drive.

TRCM

I am gonna do that on my own rig, but you should get it running correctly before you do that, as the manual fan will hide other issues easily.

The main difference in the way I am gonna do mine, instead of a manual switch, I am going to have a secondary control circuit & sensor that automatically turns it on @ 195, as opposed to the factory 218.

Mine currently, in 95-100 deg temps, runs 205 with the A/C on in normal driving.

BlueRidgeMark

That is EXACTLY right.


Simply OUTSTANDING!

lawsoncl

Test the sensor with an ohmmeter instead of blindy replacing it. A quick google should get you the resistance values for cold and hot.