Ok. I give. My '95 XJ has me fuming mad and I'm about ready to kick what's remaining of its rusty rockers clean off.

On hot days, I can't get this thing to behave. It stays right at 210° when rolling down the highway, but as soon as I get into some stop and go, the temps start climbing. It really sucks when wheeling, cause it wants to sit up around 230°-240° (which is finally where the e-fan kicks on, 230°ish), and I don't like it. I would think the e-fan would kick on sooner, but I don't necessarily want it running non-stop either. When I get on the throttle, the water pump moves enough coolant to bring it down a bit, but not for long. Cranking the heater does bring down temps some too.

In the past year, I have replaced the thermostat, housing, radiator, cap, hoses, water pump, heater control valve, and have recently switched to Delvac Super 1300 from Castrol GTX 10W-30. My oil is never milky, and my coolant always looks rather green and clean.

I have NOT replaced the fan clutch, since it seems to work fine and feels fine. I am really at a loss as to what to do. Do any of the gurus have any suggestions? Thanks in advance!

 

do you still have the fan shroud on it?

 

I would look into the e fan. If i remember right it's supposed to kick on at 215.

 

Yes, the shroud is still in it.

Yeah, it's supposed to kick in somewhere around 217-220. Is the temp sensor switch on the e-fan somewhere, or is it located remotely?

 

I would suggest replacing the fan clutch. Also, are you're temp numbers going by what the factory gauge indicates? If so, it could be giving inaccurate readings.

 

On my 90 I took loose the 2nd connector away from the fan and jumper-ed it together. When ever I turn on the ignition the elec. fan comes on. I would rather not have it come on all of the time but I am missing a shroud and until I replace it I'll use it like this as it does keep the temp. down. I stay at 210 all of the time.
Are these gauges accurate? I am used to factory gauges being more of an idiot light but the oil and water gauges seem to act like a normal mechanical gauge.
clint

 

I did wonder that. Perhaps the e-fan is in fact coming on at the proper temp and my gauge is just wonkered. I would think that whatever device is telling the e-fan to turn on would be more precise than the gauge sending unit. Is my brain betraying me?

 

1) Always verify suspect IP gage readings independently. Always. Period.

2) Design op temp is 212-215*F (I don't like it, either.) Your fan should come on slightly higher than that - and certainly not over 220*F. Could be the sensor going silly on you - OBD-I still used a separate sensor to drive the gage. Worst - could be either one. Plan on replacing both.

3) Based on experience and reports from the field, the fan clutch on the 6-242 is good for about five years. Replace.

NB: You have two temperature sensors. There is one at the driver's side rear of the cylinder head - this one drives the gage. There is also one in the thermostat housing at the front of the head - this one reports to the ECU and that signal is used to drive every other temperature-related function (including your e-fan.)

 

Thought someone had posted saying their FSM stated that the ECM turned on the elec rad fan at 217F. Don't remember what year model(s).....maybe someone can verify.

 

Sweet, just the person I was hoping to chime in. Thanks for the info man! I guess I'll save up a few bucks and get to fixing.

 

Wow - does my reputation precede me? I'm honoured, flattered - and a bit worried...

Hope this helps. If it does not; record what you did and report the results. It may bring a new symptom to light that would also be instructive...

 

you could always wire your e fan to come on at a certain temp via a thermostic switch

 

With 31's you shouldn't be getting that hot just driving around town stop and go. you could hardwire the fan but that still wont fix it. It sounds like you have replaced and ruled out most of the small issues.

The only thing i didn't see was a new radiator, check to make sure you also have good flow from the front through the condenser.

The bad thing is it sounds like my jeep and i had a bad cylinder head. This would cause venting into the coolant making the pressure and temp rise kinda like when you unscrew the cap when it is hot. The only way to check this for sure is a compression test.

 

I agree on the radiator. It could be a bad temp sender, but I know that my fine never comes on unless its real hot outside and I've been sitting still for quite a while. I would look into making sure you have good flow through that radiator. Just my two cents. Good Luck
Brendan

 

Sorry missed it. Looks like you did replace the radiator. In that case I am stumped. Could be a iny crack in the head maybe? I dunno
Thanks Brendan