nickfancher1

I've replaced everything. And I mean everything in my cooling system and my Jeep still runs warm. Replacing the fan clutch again did help a little though.

I'm thinking of getting a heavier duty fan clutch. All of my reading on here everybody says to get one for a "Grand Cherokee" and all the posts say it is a 272310. HOWEVER, that is the part number for a 2.5L XJ, NOT a Grand Cherokee.

Which fan clutch is going to do better? For a 4 cylinder XJ or a Grand Cherokee?

Thanks

272318 - Stock 4.0L XJ
272310 - 2.5L XJ
272314 - 4.0L Grand Cherokee

EZEARL

You want 272310. If you go to the NAPA site and compare the ZJ to the XJ you'll see the difference in length with the ZJ being longer. Too close to the radiator. But I don't know if it will solve your problem. Most here agree that an XJ OEM cooling system that's intop condition will handle all but extreme conditions. Like hardcore off roading. Having said that I'm running the 272310.

Tbone289

When does your Jeep run warm? A fan clutch will have virtually no effect on the temperature while you're cruising at speed.

dans98xj

Im running a fan clutch from a 98 TJ 4.0 with air. That fan clutch is only .125 longer than the stock XJ. The ZJ fan clutch is .25 longer and could effect the way it pulls air through the shroud. There is a sweet spot in fan location in relation the the shroud, in or out too far and it will be less effective.

nickfancher1

210 on the highway, 220-225 at idle

kjc

I'm curious to know if you've checked the water temperature with an accurate gauge, other than the one on your dash? I don't think the stock gauges are all that accurate.
Just a thought

nickfancher1

I have a real external gauge hooked up with a new sensor.

Stock gauge is just a light.

Also reads the same temp with a scan-tool

moparado

Does the PCM ever turn on the efan?

I have a similar issue in mid 90 deg.+ weather at prolonged idles only.
I replaced my fan clutch with the NAPA 272310 along with every single component in the cooling system with no improvement.

Everything works fine at cooler temps with the efan turning on when the temp gets a little over 210 deg. at idle.

I've come to the conclusion that the PCM turns on my efan too little too late in extreme hot weather at idle.
Likely to keep the engine hot as possible for emission regulations.

The empirical proof?
At prolonged idles, if i manually turn the efan on just a hair before or right at 210 deg. all is ok at any outside temp. including 95+ deg.

Why some XJs have this issue while other XJs don't is one of the great mysteries of the universe.

Tbone289

So, you're saying that the PCM turns on the efan at lower coolant temperatures in cooler ambient temperatures, and higher temperatures in hot ambient termperatures? That is definitely a strange one. The efan in 2000-2001 XJs should come on at 223 degrees regardless of ambient temperature, and stay on until temperature reduces to 217 degrees. On '99 and earlier XJs, the fan comes on at 218 degrees.

From the 2000 FSM:

I think the problem here may be that you're basing temperature off the dash gauge, which isn't accurate enough to troubleshoot this...

However, I think you're on to something that the OP's efan may not be working correctly if the coolant temp is reaching 225 degrees at idle, since the efan should be on at 218 degrees.

jeep94Norway

the 96 cherokee does have the temperature sender/sensor on the cylinder head near the fire wall. my experience is that sometimes air get stuck around the sender/sensor, and you get wrong readings. if you haven't done it yet its worth a try.

jordan96xj

No. The 96 has an engine coolant temperature sensor in the thermostat housing, and it is this sensor that feeds the PCM voltage readings that are converted into temperature values which can be read via an OBD2 scanner or converted into messages on the CCD bus to feed the temp gauge in the cabin (if it has one). The one back by the firewall is the intake air temperature sensor and is not used to display engine temperature and is typically quite a bit lower than engine coolant temperature.

EZEARL

When I did the cluster swap on my '96 two sensors needed replaced for the gauges to work properly. The oil pressure sensor and the temp gauge sensor in the head near the firewall.

jeep94Norway

210 when you are on the highway and 220-225 when idling, sound like you having sirkulasjon problems, in your cooling system somewhere. try to remove the little valve on the bottom of the radiator cap (use the old one). put it on and let it idle for 10 min. then give it some gas when the thermostat opens, keep an eye on the coolant overflow tank. I have done this many times and it works great, when there is still some air left in the cooling system.

also take a look at the sensor back on the head near the firewall, like I mention earlier. you can get wrong temp readings on the gauge if its air around the sensor.
go over the hose clamps, you may have a small leak when the rpm climbs near 6k. or when the engine gets cold and make a vacuum effekt in the cooling system.

jordan96xj

I think we might both be right.

I just cross checked what you said with the 95 FSM, and I think we are just describing a difference between the post-obd2 late build 1996 XJ, and the early build 1996 XJ which was probably more similar to the 95 with the sensor that fed the gauge directly. In the OBD2 system (on late build 96s), the coolant sensor is in the thermostat housing, and does not control the gauge directly. I have a late build 96, so of course that is what I'm used to seeing.

moparado

Here we go again.
The problem as i see it is that at extreme hot ambient temps. the engine temp increases exponentially at idle and quickly to the 'point of no return' so to speak. Then at that point it takes it takes a lot longer for the efan to catch up.

Experimented without using my manual efan switch at hot idle at a long McDee drive thru line. It was low 90's weather.
When the temp got past the 'point of no return', the efan eventually turned on but it only stabilized the engine temp not cooling it down.
During that time period, my engine started to growl from the increased heat likely caused by a precursor vapor lock condition.
And by that time i was back on the road again where the air flow from the road speed cooled down the engine back to <210 degs.

At hot idle, if i manually turn on the efan before the 'point of no return' the engine will cool down below 210 in a few minutes and all is well...hot weather, prolonged hot idle all the live long day.

IMO at this point, if the PCM efan enable set point turned on the efan at or slightly below 210 deg. that would solve the problem.