4.0 runs hot what is too hot?
 

So I recently purchased a 1991 XJ with relatively low miles. It has been modified by a previous owner for off-roading which is what it is going to be used for by me. I've only done a few trails with it but I've noticed that it seems to run hotter than it should. It will make it to the third hash mark on the temp gauge and a bit beyond it so 235 ish. I've read that the 4.0 does run hot but this seems to be too high, am I right in my thinking? And if so should I start looking to replace the radiator the clutch on the mechanical fan seems to be fine and the E fan is on a toggle switch so I'm able to turn it on whenever it starts to get close to 210. Is there anything else I should be looking out for with the cooling system.

Flush the cooling system, for starters. Normal operating temp for the 4.0L is 210 +/- a couple degrees. The 4.0L does run hot, but 235 is a bit much. Point an IR thermometer around the temp sender at the back of the cylinder head to make sure the gauge is reading correctly.

Normal operating temp for most XJs is around 210 - 220 (my 97 averages around 215 when its hot out,) 235 is a a bit hot.