Cooling dilema
 

Howdy all.
Thank you for allowing me to join. Long-time jeeper. New XJ-er.
A month ago I bought my new toy : " Miss Behavin' "
2001 Cherokee Sport. 4wd 4.0 i6 Auto 215,xxx on the Smileometer mostly stock
Naturally, she has a few....quirks. I would most of them out, but there are still a few.
Cooling system : (This one has me slightly puzzled.)
I know the 4.0 has a reputation for running hot. But I find that mine is usually COOLER than I'd like.
She stays down around 160-ish even after cruising or for quite a while.
I flushed the cooling systems and installed a new 190 thermostat...same issue.
Occasionally she will climb up to 190-210 (where I want it).
When Im off roading, she will hover at 200 most of the time. then creep into the 210-220 range.
Ive learned that when she gets this warm, her idle speed starts for fall off and she can stall if I let her. And if she stalls, it take some finesse to get her restarted.
Ive also learned to pop her hood and let her cool off for a few minutes, that resolves the starting issues.
I did install the fuel-rail and injector heat shields. Seems to help some but the problem persists.
Heater works great!!! when it works.
Electric fan does NOT engage even at 210 degrees. Gonna try to see if it responds to direct 12v to isolate the issue.

Sooo.... Ive done some reading and watched lots of video on XJ cooling.
I've heard about upgrading the fan clutch to a WJ clutch,
replacing the OEM radiator with a 3-core,
Removing the mechanical fan and replacing it with three electric fans,
cut in hood louvers,
Cold-air intakes,

Everyone has their own "magic fix" for optimum XJ cooling.

But this forum is where I hope to find XJ-Specialists.

What is the prevailing wisdom on the wisest way to go about making sure my 6-banger doesn't go "China-Syndrome" (old movie reference, for the youngsters).

Thanks in advance. Im sure I will have lots and lots and lots, and lots and lots and lots and lots.......of questions to come. ;)

V.

Yeah my electric fan cuts on at 210, if yours isn't cutting on that's a prob. But these things run warm. My mom bought our Jeep new, my Jeep now. Have you checked the heater core, wet floorboard. My 95 has a little heater element for lack of better words in the dash, I guess for additional instant heat. Although you have good heat, check that heater core. I have had several overheating extravaganzas, my mom got it so hot it popped the heat plugs once(20yrs ago)ive had two water pumps die without weeping warning. After replacing my factory rad with a aluminum 3 core, new hoses, water pump, and thermostat, I run right and have for years. A lot of folks hate them but I always run the failsafe thermostats in my rig, as many overheating issues that happen it gives me price of mind against overheating, and I know when it fails cause the car doesn't get hot. And I never worry about overheating, and a stuck close tstat that prevents me from getting home. Sorry that's my 2 cents. Hope it works out

I have a Spectra factory replacement radiator, 4cyl XJ fan clutch, 180* thermostat, fan shroud in place and clean coolant. No overheating issues at all, it usually stays around 190 and I haven't seen it go over 215, even off-road with the AC on in 90 degree weather.

You can test the fan by jumping it directly to the battery as planned (polarity doesnt matter), or by disconnecting the temp sender in the thermostat housing, and the PCM should turn the fan on. The fuse for the fan is in the PDC.

Borrowed pic from CCken.
https://www.4x4brasil.com.br/forum/a...c1997_2001.jpg

Technical questions belong in the technical section.

I've been told, but haven't looked for it, there is a temperature sensor switch for the electric fan on the left side tank of the radiator that turns the fan on and off. Trace the wiring back and see if it's there.

There is no sensors or switches on the radiator, the temp sensor is in the thermostat housing.

This is the tech section , your link is to the Grand Cherokee tech section.

So you're saying the switching is done in the PCM? I know it is in the WJ, but wasn't sure the XJ had that as well.