I spent some time rambling around in an old quarry in low-box and low speed. A few axle twisters and short steep climbs and plenty of mud. I noticed that on a couple of occasions the temperature gauge was up in the red.
I checked coolant level which was fine but I could hear boiling, there was no blockage in the radiator and found nothing that seemed untoward (it was a chilly day).
Would it be usual to have high temp occasionally. I have the stock fan fitted.

Thanks
Dave.

It could be your thermostat sticking. I would try replaceing that first since its cheap, and mabey flushing and refilling the system. If that dont fix it then you might have bigger problems, like clogged rad or bad water pump.

Maybe your belt was slipping from the mud. Did you notice any squealing while playing in the mud?

No it is not usual. You need to find the problem and get it fixed.

It could be that your plastic tanks on your radiator are seeping...

Have someone run a pressure check on the system, especially if it seems low on water.

Do a flush, thermo replace and refill.

Thanks for the info Guys.
Since being back to highway driving the temperature seems to be behaving. However, I don't want to take that as a false sense of security and then get caught out at the worst possible moment.
There was no squealing or other indication that the belt was slipping and the rad was surprisingly clear and the coolant level is fine.

I will change the thermostat and flush out as suggested straight and away, it can only but help. I just hope the pump is OK.

As you mentioned the plastic tanks I've just had a run around until the engine was up to temp and checked them over. All is very dry but I will keep an eye on them. Didn't realize just how exposed the plastics are down there. Looks like some sort of protection is in order

Thanks for the help.

Dave.

tj 2 row plastic radiators are crappo!. i went through two of them(luckily under warranty) before i was fed up w/it and went w/a heavy duty 3 row from www.radiators.com.
i was overheating badly and i did the therm, then the water pump and still nothing. i kept getting crap in my radiator like dirt and stuff. for whatever reason my new radiator is a godsent. runs much better to.
also, your clutch fan could be bad. if it is, invest in a ford taurus 4.3 electric fan from the junk yard for about 40 bucks and wire it up. that way when your in the mud you can not have to worry about throwing mud all over and having it get up into your flow over container and having it then get into your radiator.. just a thought.

iPlay in mud alot here in florida and have had the same happen on my 94 yj and 03 tj usually the belt does slip but won,t be noisy cause the slime acts like a lubricant also the rad gets mud clogged in the fins,but then again we have serious mud here!

Hi Guys,
Thought I would keep you up to speed on what the cooling problem is/was.
Like everything else it turned out to be one of those 'it's OK now so I'll do it later jobs'.
To and from work is literally a 15 minute ride for me so the overheating never raised it's ugly head again. The I had some running about to do in town and sure enough... up into the red.

Got myself a new thermostat as the starting point to resolving the problem and while fitting it noticed that my fan wobbled on it's shaft. Looks like the bearing is shot (viscous clutch type) and guess what, it's not sevicable. Just ordered a new unit. It will be here in 2 days and it stung me for £164.00 ($310). Ouch!!

dumb dumb dumb.... should of just done a ford taurus electric fan conversion for about 40.00. Wiring and therm puts you at a total of less than 100.00. then it cools better than a viscous fan, gives you some hp gain and you can turn it of at water crossings.. send it back man!

This message has been edited. Last edited by: brokenUjoint,

yep, i used the dual electric fans out of a mustang and all i can say is. It definetly keeps the temps down. plus it sounds like i have a jet engine under the hood