4.0l XJ Overheating

[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...

[Geejeep]

Originally Posted by 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...

Thanks, found it here for anyone else considering the same:
http://www.go.jeep-xj.info/HowtoTaurusFanInstall3.htm

[shakes]

Being it was 41°c here, and I was crawling in peak hour the cooling system got a damn good workout. It sat solid at the first line after 100 on the gauge until we started pointing slightly uphill. Dash went nuts and it jumped up to the first red line.. sat solid there for 10-15minutes. we crested the 'rise' and I turned the heater on at the same time from the AC. Within about 3 seconds the temp dropped back to the first line and sat there. Until home (another 20 mins)

Now I'm home the bonnet was far to hot to grab with bare hands. the overflow was full but not overflowing. The overflow is also literally boiling (i get the pressure raises boiling point bit)

How normal is this for the XJ? a few months ago now ~5000k it got a new rad/clutch/t-stat/waterpump/hoses/cap. I'm guessing to improve on what is there now is the ac switch, trans cooler and what else?

[shakes]

Have I got this right? it was bubbling cause the inlet is at the base of the overflow.

My best explanation was a random air bubble working it's way through... mixed with a somehwhat dodgy rad cap, the temp slammed down when it opened released the pressure and partial air lock ??