SlickXJ

Hey guys, a quick search didn't hit on much. I was wondering what are some basic things I can do to help the cooling system for my 96 XJ. It's got pretty new hoses, and I flushed the heater core last winter, but that's it. Hottest it gets is about 225, but I want to prevent it from going higher.

kgm

Replace the parts.

Depending on when it gets hot can help you determine what parts are failing, but I found mine to be a cumulative effect. New radiator helped a little, new waterpump helped, new thermostat helped, still getting warm on climbs because I haven't done my fan clutch.

Doogluus88

X2 on replacing stuff.

In the last year I've replaced EVERYTGING (except the heater core) in my cooling system. Each time I replaced a part it helped out. Make sure your fan clutch is in good working order, it gets overlooked a lot. One way to tell if your fan clutch has gone bad is to pop the hood with the motor running, then turn the engine off. If the fan stops spinning quickly it's ok. If it continues to spin and spin and spin you need a new fan clutch.

Turbo X_J

That's not an accurate assessment, if it's more than likely OE for $30 and 30 minutes of your time just replace it.

Doogluus88

Hmm... Well, that's how a lot of guys on here say is one way to check, so... All I know is my old fan clutch would spin forever after shut down and my new stops pretty quickly... Just saying.

The point is to check your fan clutch when doing maintenance on the cooling system. It's very important

SlickXJ

It just gets hot normally. As in after like 10 minutes of driving, it'll be up to 200-210, then after about 15 it'll peak at 225 and fluctuate between 215-225. This is based on my scan tool live readings. I'm fine with replacing stuff, I just need a list of what to replace. The hoses are new, as in the last 5k miles. I have only had the car for the last 5k, so I don't know the extent of the work is except the motor was rebuilt at 280k and everything I've personally done. Like the NSS, TPS, CPS, some electrical work, and more. I haven't touched anything on the cooling side yet besides what I've said. So I need to replace:

- Hoses (potentially)

- Radiator (Is there a way to tell the manufacture date or a way to tell if it needs to be replaced besides a leak)

- Thermostat + Water Pump (What tstat does a 96 XJ use?)

- Fan clutch

Is there anything that should be done at the same time?

Bocefus

It sounds like it is running a little warm while driving down the road, which is a flow problem. A new radiator, thermostat and water pump should rectify this. I would also change the hoses and fan clutch as well while you are digging into it for only minimal additional expense. You can pretty much change everything for only a few hundred.

Be sure to get a Mopar Water pump. I got mine on Ebay for around $50-55. The parts store places use cheap chinese bearings that don't last while the Mopar units have the good USA bearings. A Mopar Thermotat should be used as well, also found on ebay. I just used the toughone/Carquest radiator at Advance auto using online discount codes for super cheap, around $65. Fits and works perfect. I just reused the original radiators back plates.

extrashaky

That test is not reliable. None of the spin tests are reliable. Mine "passed" the spin tests and was still not pulling air properly.

If you suspect the fan clutch is failing, the only reliable way to test it is to remove it from the vehicle, move the spring 180° to the opposite tab from where it's usually mounted and put it back on the vehicle to see if the overheating issue stops. Moving the spring locks the clutch, effectively bypassing the clutch's normal function so the fan is always pulling air. If it's okay, you have to pull it off AGAIN to put the spring back where it's supposed to be. If it's not okay, you have to pull it off again to replace it.

But if you're taking the stupid thing off and on and off anyway, you might as well just go ahead and replace it instead of testing it. So it's really not worth bothering with. Just take a crowbar to your wallet and pry out the $35 for a new one.

BimmerJeeper

I would love to replace my entire cooling system.
Water pump, thermostat, radiator and hoses.

Is there a step by step illustrated guide to doing the XJ cooling system?
Or is the only documentation basically "Remove radiator, bleed air, drink beer"

Orlo

Use the search function on here and READ! The cooling system maintenance has been explained and illustrated on an almost daily basis on this forum. If you still want more information, buy a FSM and you can study the information in there. Now, go do your homework.....

GregGA

I think most of the "running hot" issues are a lack of maintenance by the previous owners.

I've owned my 87 since new, and it has never run hot. Ever. I have the original radiator. I've replaced 3 water pumps(and thermostats) and one fan clutch, plus the hoses. The flush/fills were done per factory recommendations.

Runs at 195-200 per an infrared gun.

kgm

I used Peak's flush before I replaced my parts. I drained my coolant in the summer, and ran just water & Peak flush with about maybe 5% antifreeze to try to prevent any extra rust (probably not needeD) and drained it every hour or two of driving. Mainly I'd drain it every few days.

Biggest issue with cooling system is the quick connect for the transmission. Mine was a PITA, and I cut it and spliced it back together using ATF hose. Don't use fuel line.

Metmknice

Beg , borrow, steal.. or I guess buy, an IR temp gauge and confirm your actual temp. The gauge reads what the sensors do, and so does your scanner. Get it up to NOT, and use your IR gun on the stat housing, to check temp. Also, some people put their t-stat in a put of water and boil the water to confirm it is functional. They are cheap and easy enough to replace, so buy a new one and test it first. Premium 16 lb, non lever cap. Also, you can use the heat gun on your rad and see if there are any areas that may be clogged.
I have confirmed that my gauge reads about 10-12 degrees over what actual temp is.
I also, meow, run a bottle of water wetter when I change my coolant.

SlickXJ

My gauge reads about 250 when the scanner reads 210. The gauge has always been off. Previous owner looks like they did some funky stuff with the temp sensor.

Doogluus88

I'm not 100% sure about the 96, but my 94 has two temperature sensors. The one on the thermostat housing sends temperature info to the main computer. Then, there's one on the back of the head on the driver side that controls the gage on your dash.