Temp climbs at idle.
 

Hey guys I am having an issue with my xj. It's a 4.0 and while in a drive thru I noticed the temp was at the third line ( line after 210). I turned off the AC and it sat at the third line for a little and then went back down to 210 after a couple min. From what I have read this seems to be an issue with the fan clutch. Wanted to see what you guys thought?

Yes , the fan clutch or the electric fan is bad . you need to check both the fans .

Ok I was running the AC and every time it turned on the compressor the fan would turn on as well. Does that mean it's in working order or is there another way to test that? It seems like the electric fan would be the issue here because it was running hot with the AC on but fine with it off.

I've seen the electric fan turn on but run slow when it's starting to go bad . all you have to do is look at it when its on it sould pull lots of air and then make sure it turns free when off.

Also check it is getting right voltage.

The electric fan should come on right away anytime you use the AC and whenever it hits around 210. I'd gamble and say it's probably your fan clutch but test both. In good working order just the engine fan should keep the engine cool and the electric is kinda the back up. Good Luck and let us know what you find out:)

Ok guys according to that test the fan clutch is in working order.

When was your last coolant flush? Mine used to creep up at idle with the AC off. Got the AC working and a coolant flush and it's never above 210, usually a tick below.

I haven't done a coolant flush since. It looks like the P.O. Might have. The coolant is full and bright green still if that matters. The temp only climbs with the AC on. If it's off it stays around 210 while idling and much cooler driving around due to increased airflow obviously.

Have you had a chance to check the voltage to the fan? If the mechanical clutch is good and the efan is coming on, I gotta go with gerry and say check the voltage.

I have not but I will check it tonight after work.

Unless you know for sure how old your fan clutch is,and then that's still not saying it's good,you should replace it. They can be good,bad,OR somewhere in between to the point that it may not be in good enough condition to do it's job. JMHO that there is no definitive test.