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overheating xj

Posted: Mon Oct 13, 2008 8:25 pm
by jeepn
i am the new owner of a stock 2001 xj with 90000km. i took it for my first trip on the beach on the weekend and it boiled its head off. i heard it is a problem with them and was wondering wat mods people do to keep them cool ie- what size radiator, cap pressure, thermostat? it is going to be a weekend play rig but need to get this fixed first!

Posted: Mon Oct 13, 2008 9:05 pm
by vk2icj
Yes XJ's like to get warm and then don't like it when they are.

I'd make sure your cooling system is really up to par. FLush your radiator and ensure your aux fan comes on. AS to mods try

http://www.ausjeepoffroad.com/

You'll find everything there

Re: overheating xj

Posted: Wed Oct 15, 2008 2:36 pm
by Steve F
jeepn wrote:i am the new owner of a stock 2001 xj with 90000km. i took it for my first trip on the beach on the weekend and it boiled its head off. i heard it is a problem with them and was wondering wat mods people do to keep them cool ie- what size radiator, cap pressure, thermostat? it is going to be a weekend play rig but need to get this fixed first!
If it boiled its head off then there is something wrong, they get warm/hot but shouldn't boil. I run mine hard on the beach all the time (and I run 32" tyres etc) and have never had to worry about it that much.

I run standard radiator and all the other cooling bits, mines a 2000.

Cheers
Steve

Posted: Wed Oct 15, 2008 8:58 pm
by jeepn
cheers for the replys.. my car has got a 16psi radiator cap wat does everyone else use? my old mans grand cherokee 4.7L runs a 22psi cap. the gauge was sitting just over 100 and then it just maxed out pulled up and there was coolant everywhere. thinking cap might be releasing to early?

Posted: Thu Oct 16, 2008 7:20 am
by Steve F
I think the stock cap is 16psi but there is no harm with replacing it with a new one, it may not be holding pressure or clamping tight to the radiator neck, did the coolant come out of the cap? Sounds like it did.

I have a scan gauge (reads and shows data from the OBDII port) and it has run as hot as 118C with no problems (heavy sand in summer, and it still dropped down to 105C when the load eased off), with a 50:50 mix of coolant and water it shouldn't boil until around 125-130C

Cheers
Steve

Posted: Thu Oct 16, 2008 12:20 pm
by Wooders
What size/type tyres do you run? Were you in low range? Tyre pressure?
If it's on standard tyres in hirange the XJ will work bloody hard in soft sand.

Xj's tend to run warm - there are a few tricks to getting the to run cooler - but if it's boiling its titties off then something isn't really right.

Posted: Thu Oct 16, 2008 4:54 pm
by jeepn
it has stock tyres and was running them at about 13psi with a mix of high and low range.

Will start by giving the cooling system a good flush out and a new cap. Is it best to keep it in low range in soft sand. I was a little worried as the manual said not to go over 40kmh so as to not overspeed the engine but thats y it has rev limiter isnt it.

Posted: Sun Oct 19, 2008 5:38 pm
by FredE
Might suggest that if you are going to flush out the system that you remove the radiator and get it serviced (cleaned) by a Radiator Reparier They remove both tanks and push a blade through each tube to make sure that there is no blockages then refit the tanks and pressure test it to make sure that there is no leaks While its out you can give the engine and heater a REVERSE flush and remove the thermastat to check that its opening fully
I have a 2001 XJ with only 60,000Klm and have already replaced the radiator with a "All Metal "one did away with the OEM one with the plastic tanks