also bypassing the heater core, if yours is leaking, will cause over heat issues. Ask me how I know. Block the lines, don't re-loop them. I'm saying that this is your issue but I just dealt with that so it's something, lol.

 

Just a thought. Would a hi-flow water pump help?

 

maybe, maybe not.

you need to find the source of your cooling problems, not try and cover it up

 

What's the "acceptable" heat range of the in-line 6. I know operating is right around 210. How much over 210 is safe before you should get worried? Because mine does the same thing (not to thread jack) when sitting in traffic, but it doesn't go very high. The fan kicks on and all seems to stay well.

 

A brittle but vital part.

 

Does the plastic electric fan kick on when you turn the a/c on in the older xjs? For some reason I don't think mine comes on when I turn my a/c on in my 92.

 

Mine doesn't turn on either (2000) but I can't find a way to diagnose it.

 

I don't have an answer (I sure someone else does), but I've read on here that just having the AC on doesn't mean your electric fan will be running. The AC condenser has to reach a certain pressure or temp- not sure of the details. My 01 XJ has never gone above about 212, and I rarely ever use the AC, and I've never seen or heard my electric fan run.

 

mine will usally run at 195* til i stop and then it will run up little.if sitting there idleing for about 10 min the fan will kick on around 215*.once you get your overheating problem fixed look into some hood vents so you can let a lot of that heat escape and keep that temp. down,that will be my next project.

 

I've been looking into hood vents too. I'm not quite convinced that they would help lower coolant temp.

 

The louvers/vents do help.

Another thing that a lot of 00-01 owners do is to install a timer on the electric fan. When you turn off the vehicle, the electric fan stays on for a predetermined amount of time.

The above solutions are probably the top 2 fixes for 00-01 owners that are experiencing "heat soak".

 

OBD-II temp range is 160F to 218F. Below 160 sets a CEL, above 218 turns the efan on for max cooling. The factory idiot gauge is pretty much rigged to point at/about 210 most of the time as long as coolant temp stays in a normal range monitored by the ECU. No where in the FSM does it say anything about 210F being optimal.

 

Others have posted that '00/'01 efans only come on at 218F coolant temp where as '99 down efans come on with either the a/c compressor or 218 coolant temp. Someone also posted that the dealer could re-program '00/'01 model efans to come on with a/c.

 

My Cherokee ran hot all the time so I went all out and replaced the mechanical fan with an electric fan, installed a 2 row rad, flow master water pump, Mr gasket hi flow thermo stat, ground out the inside of the thermo housing for more volumn and installed hood vents.
On a 100 deg day at freeway speeds it runs around 200-210 and the electric fans never come on. When I'm trail riding at slow speeds they will come on around 235 and cool to 190 in about 3 minutes then turn off.
It's the single best upgrade I've done to my jeep.

 

Why not set'em to come on a little sooner......like the factory set-up.