4.0l XJ overheating? Start here - the basics!

[iancj10]

ok guys its a 96 4.0L as far as the cooling systems health goes i know it doesnt leak, visually its all fine, heater works,cap seems to seal ok,thermo is wired to a switch on the dash, clutch fan seems to function normally,trans cooler is still through the rad (thats gonna change)
i was in high on the beach maybe try low next time im just used to my cj10 it eats the sand in high
i also have a 97 & a 95 for parts
cheers ian

[iancj10]

as for the vehicles history i can tell it was well looked after for most of its life but in recent times has been treated roughly so at a guess at least 1 to 2 yrs of neglect
cheers ian

[Roler]

ok guys its a 96 4.0L as far as the cooling systems health goes i know it doesnt leak, visually its all fine, heater works,cap seems to seal ok,thermo is wired to a switch on the dash, clutch fan seems to function normally,trans cooler is still through the rad (thats gonna change)
i was in high on the beach maybe try low next time im just used to my cj10 it eats the sand in high
i also have a 97 & a 95 for parts
cheers ian

You have been planning this, haven't ye?

as for the vehicles history i can tell it was well looked after for most of its life but in recent times has been treated roughly so at a guess at least 1 to 2 yrs of neglect
cheers ian

IMHO, investing in cooling system maintenance is likely one of the best things you can and should be doing for your XJ. They run on the virge of hot and with all cooling parts optimal, should be able to keep up with things. But there is not much room for error, since its tight and hot in that engine bay..
Driving in the sand will put the system to the test and towards its limits, and when there is a subpar condition than under normal driving would not give issues, it will bring it to the surface quickly. Be glad it didnt overheat, but take it as a warning shot and now is the time to prevent repeats.

So, with a second hand XJ, unless you have the receipts of the parts that were replaced, I'd treat it as in need of a thorough cooling system check/ refreshing. Give your radiator a good clean or even better, have it rodded/cleaned, get a new waterpump and viscous fan clutch (both parts are not overly expensive), think about a thermostat (OEM) and check hoses (squeeze them, if you can hear them crackle, it means the rubber is old and up for replacing). An aftermarket transmission oil cooler is a yes.

What does your coolant look like? Nice and green, or rusty brown?

Mine only overheated twice, years apart, and both under heaviest of circumstances, from which one was in soft sand (and yes, I think low might be preferred over Hi in soft sand, with an XJ)

There are many opinions on radiators, trans coolers etc etc But I'd start with the basics. A refreshed and proper working XJ cooling system should be able to deal with pretty much what you ask it to do under all circumstances.

CS maintenance, it's peace of mind. Just my 2 cnts, but that's because I hate having to keep an eye on that gauge in the right bottom corner every time I climb a hill on a hot day

[iancj10]

i doubt it has a thermostat after watching the gauges while i drove it around town today
but im going to get my cj10 back together before i open it up to investigate incase i open a can of worms
cheers ian

[Roler]

i doubt it has a thermostat after watching the gauges while i drove it around town today
but im going to get my cj10 back together before i open it up to investigate incase i open a can of worms
cheers ian

What did you notice on the gauge(s?)
No thermostat will give slow engine warm up..

If you have no thermostat indeed, I'd start from scratch because in that case the PO was likely trying to deal with a cooling issue and did the ol' no-thermo no-no

[junglejuice]

It only takes a couple of mins to open up the thermostat housing to check the presence (or not) of the t/stat, I'd do this as a priority as engine wear is very pronounced without a t/stat...

[nymles2015]

my 1996 xj gets hot....!

Have been reading post by Rodgebone with much interest on a very informative article re xj six cylinder engine overheating issues. Firstly congratulations on a great article. Found this web site after searching the net for solutions for my 1996 XJ CHEROKEE, now i need to find a solution that works. Would appreciate any positive feedback from guys here who have tackled this problem with success. Have been looking on a website Liquid Intelligence, who have a range of products which may help. ie products 115,239,500, and high flow thermostats. Purchased my 1996 JEEP CHEROKEE XJ Sport/Classic six,petrol,lpg 12 months ago, this summer here in Adelaide we have 4 days of above 40 deg c. Recently had to go out, ambient was about 38deg c and 30 min trip each way and the temp gauge when i got home was nudging 115, i am concerned that its getting too hot and will take necessary fault finding. When i purchased the car it had 65k original k's now only just getting to 69k. Its been well looked after and serviced by time not kms and appears to be original and well kept. Cooling system drain and refill in 2014, running the green 50/50 chrysler product, all the obvious things like belt,fans,coolant level seem okay, not loosing any coolant. I am thinking of changing the thermostat with a liquid intelligence high flow one and there 500 product. After talking with Peter at Liquid Intelligence he claims the 500 product would give an improved thermal capacity of 35% increase.
So what do you guys think.....suggest.

[LuluBelle]

I cant get my 1996 to run cool changed every thing see my frustrating thread