Either you're running a really low t-stat, no t-stat, your t-stat is stuck open or your temp gauge is wacked. Factory t-stat is 195 and most people say the factory gauge displays 210.

 

I just put in a 180* thermostat, so I will let you know what it says when I do this tonight.

 

it does unless it's pretty cold outside

 

.......or why not run a brass nipple in the heater hose that exits the t-stat housing......coolant constantly flows thru that hose. Need to run a ground wire, unless the aftermarket gauge is mechanical.

 

I don't see how you would get a nipple to seal in a hose.

I would have put it in between the heater hose tube and the water pump if I would have known before the water pump went on. I don't want to pull the water pump just to remove the tube and put in a sensor.

 

The hottest coolant is in the cyl head......that's the best place to get a coolant temp reading......from the coolant that's in the head or has just left the head.

U use a nipple with 3/4" hose barbs.

 

I tried the same t-fitting setup to add another temp sensor for a fan. The temp reading was off by 20 deg. I verified it twice with the fitting in an out driving the XJ around for two weeks. My temp with normal driving was always 195. With the t-fitting it never got over 175. 20 deg could mean a lot when trying get out of a mud hole or over a rock.

 

After reading this thread I did the exact same setup on my xj and it DOES work.




It made me very happy to see my temp gauge finally working and sitting at 210 at idle




But I noticed on my way to class in stop and go highway traffic I was running a little hot



And as you've guys said its 20 degrees off?
So am I overheating?..... I'm a bit worried now that I see it's been running this hot for the last 5 months I've had it.

96 jeep Cherokee sport with 99 engine swap
I6
Rad was replaced by PO
water pump is good
Mechanical and e fan are working
No leaks or anything else.
Drives great

 

Bump

 

that reading is when the e-fan should kick on and bring the temps back down. That is normal in stop/go traffic and at drive-thrus. If you're running over 215 constantly though there is a problem.

 

Yeah that isn't normal by any means. Time to overhaul that cooling system of yours. Do you have written record of when the radiator was replaced or are you going off of the PO's word? And how do you know the water pump is good? Did you replace it yourself? I would replace every component (radiator, water pump, thermostat, fan clutch and hoses) in a new to me XJ. The cooling system is not great by any means and everything needs to be in tip top condition.

 

I'm going to make a new thread about this now

 

Seems a little toasty.....presume u still have cool/mild ambient temps so even with a 195 stat temp should be below 210, I would think.

 

I had the same problem after swapping a 98 zj motor to my 91 xj. I just drilled and tapped the head at the same spot the other head had the temp sender.

 

-1988 Renault 4.0 closed cooling system mounted directly to radiator-

-75% original closed cooling system '88 4.0-

-The only other comparable sensor is connected to exhaust manifold '88 4.0-
Hopefully this helps someone out cheers!


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