4.0l XJ overheating? Start here - the basics!

[Rodgebone]

sounds like the t-stat is stuck open

[junglejuice]

Originally Posted by Rodgebone

sounds like the t-stat is stuck open

Sometimes maintenance doesn't help when you replace a perfectly fine working t/stat with a new potentially dodgy one....

[rastus2571]

When I did the scenic rim trip with the boys from the patrol 4x4 forum my xj was bubbling and overheating with about 2-3 hours of low range offroad hardcore rock crawling work.

The green machine was working hard with those lockers and centipede 31's.

Jason on here (who came out with us for the day) put me onto a tip of folding the wings
back and down from the vents under the bonnet, I did this mod and found it did slightly lower the temps running around at home.

I did not do this on the day.

However I did pop the bonnet on the day and left it on the safety latch for the rest of the day to get the hot air out under his advice.

So what I have done for mine now is left the main guts of the thermostat in and raised the back of the bonnet up with longer bolts and washers to let it get the hot air out at a 25mm raise and it sits on 70 now no matter how hard I push it.

And I do work the green machine. The bonnet raise gets the heat out.

I am also putting twin GU scoops on the bonnet at the front for more flow.




Worked a treat and dropped it from around 110 back to 90.

[junglejuice]

Originally Posted by Rodgebone

sounds like the t-stat is stuck open

On Saturday I removed the new Tridon t/stat and fitted my original 8+ yr old t/stat and then proceeded to go away for the weekend, did 630k and the temp was back as stable as ever and at the normal temp range again.....

[Raisins78]

Good tech thread guys.
Can i get some advice? I just bought my first jeep (95 XJ 4.0 auto) and was wondering what i should do with my cooling system?
Obviously ill make sure its all in top condition (new alloy/plastic radiator just been put in before i bought it)
I live in Newman and we get upto and over 50degC ambients in summer.
We also dont want to overheat and get stranded in the middle of the desert with no phone reception.
so what coolant mix, what thermostat etc should i run?
should i upgrade the radiator? and to what or which brand/type?

I am going to be spending the next month or so replacing and modding most of the car, and reliability is right at the top of my priorities (always as been)
Things like cromoly axles etc are first on the list (as ive heard the rear is prone to breaking), before i get a lift kit etc just for strengths sake.
I was also going to run an external auto cooler, to take some load off the radiator, just haven't found the best place for it yet...

I just want it as "overheat" proof as possible, just like im going to try and make it as unbreakable as possible (may even be getting bigger diffs, think they were 44's, instead of an axle swap)

Thanks in advance guys

[Geejeep]

Hi all,
My 95 XJ got fairly hot (110) on the weekend after a long climb in low. The rest of the cooling system is in good cond and never usually sits above 95 to 105 in traffic. Can the factory thermo fan be wired with a manual switch so it can be flicked on to aid in cooling even when the air con is not running? If so, is this fairly simple to do?
Regards,
Andrew.

[junglejuice]

Yes it can, do a search for this as it has been covered before although if the cooling system is in good nic then it shouldn't go over 95 in traffic...