hi, im from quebec city, Canada, and I recently bought a 1989 xj, everithing about the truck is ok, execpt one thing, when im in the trail and I do my thing, the temperature of the engine up, I know that a lot of 4.0L doing this, and I just want to know what you have done to solve the problem... I put a switch in the cab for the electric fan and my truck still hot....

thx for answer

TONIo STyle

Sry for my poor english, I speak french

 

Need more information. How hot is it getting? Have you replaced and or done anything to rectify it?

 

just before the red line... I change the termosta and check the prestone and every things were ok... I think that I will put some hole in the hood... some one did that I would like to see what its look like...

 

You might try flushing out the coolant system before you start cutting up your hood..or go for it, and add some speedholes too!

 

x2 on flushing the coolant also change the thermostat and heater control valve and you might also want to replace your fan clutch theyre known to bad and if all that doesnt work you could order a csf 3 row radiator they say that they are the best radiator you can get for the money

 

x2 on the clutch fan.

and try not to run a/c for too long while on the trail.

 

is your a/c on when the temp is running up? is your electric fan running up to par?

 

I have an 2 fans on mine; stock fan and an aftermarket with a toggle switch. If you drive slow or on trails in XJ's there's not enough air flow sometimes.

 

i have the same troubla and have a clutch fan, however have purchased an electric fan to add to the stock clutch fan. and when i very first bought it it would overheat at any speed, so i change thermostat. its only ten bucks and would be a good idea anyway. Hello to quebec

 

i dont use a/c when im on the trail and yes my electric fan is running.

someone told me to just dont have a termosta, is it good? last trail i did, all my electric system blow up....

 

keep your thermostat in, but change your clutch fan.

a quick way to check your clutch fan, with your engine off, when hot, your clutch fan should be hard to spin by hand. if it has little resistance, the clutch is worn out.

 

Have you tried to tighten or loosen the pressure bottle's cap. The 89s don't have a radiator cap , just the pressure bottle. When it is loose or too tight, it will cause the engine to run a little hot. Find the sweet spot and mark it so you know like I did. Solved a big headache for me. Hope it helps.

 

When your temp starts climbing check to see if your upper and lower radiator hose are not collapsing. You are might have air trapped in the system also . Search for "burping a closed cooling system" there is tons of info on it.

 

heres a pic with hood vents

 

Try and get a hold of a laser thermometer. Check the temperature of the radiator at the top and at the bottom.

Mine had a difference of about 20*, so i replaced it with a 3 core. Works really well but watch that fan clutch - it can jump up and hit the rad.