Does anyone know the difference between the factory OEM "severe duty" thermostat (180*) vs. the standard OEM t-stat (195*). I went to the stealership to get a new factory t-stat and I had both of these to chose from for my '96 4.0L. Those of you who've been sucked in the heating problem threads know that a lot of people recommend the 195* OEM standard t-stat because it comes with the little ventilation nipple/hole that's not in after market thermostats. They're special order parts and I'm inclined to buy the "severe duty" but would like some advice. Yes, my XJ runs hot and overheats and I'm trying to restore all cooling back to stock, so I can troubleshoot it properly.
-
Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.
Diff between OEM regular t-stat and "severe duty"?
- Thread starter Planetcat
- Start date
Runnin'OnEmpty
NAXJA Forum User
- Location
- Southeast USA
I have a 180* in mine, and it works fine. If your's dosen't have the bleed hole, simply drill a 1/8" hole in it, and install with the hole toward the top.
The ECU goes into closed loop at about 140*, so a 180* thermostat won't hurt a thing.
The ECU goes into closed loop at about 140*, so a 180* thermostat won't hurt a thing.
89xj said:
Yeah, I've put my electric fan on a toggle switch to avoid it going on via the ECU at 218*. I usually turn it on when it gets to about 205-210*. It just prolongs the overheating. I ripped out my flex a lite and put back belt driven fan. The last thing I have to do is to put back an OEM t-stat. Right now, I have a Robert Shaw HD 180* and I'm sure it doesn't have the bleed hole. I just assume put in a new one for $15, since I've already boiled over with this one.
banjosrunderrated
NAXJA Forum User
- Location
- Warren, mi
I know most of you recommend putting the fan on a toggle, but I don't trust myself enough for that. Is there any way to make the fan click on at less than 215-218?
Majo
NAXJA Forum User
- Location
- Watertown, NY
banjosrunderrated said:
I believe the electric fan switch is a special switch that kicks on when the temperature is at a certain level. When the temperature hits this level the switch closes thus allowing continuity, thereby allowing current through. When it's open and it's not at the required temp to close it it's gonna be open. One option that I concidered was hooking up my e fan to a switch along with a rheostat or potentiameter (sp) in line so I can adjust voltage levels too it thereby allowing it to run on different settins say speed levels 1-5... Let me know if you need help, I can come up with a diagram with you. I'll looking into a way of making a switch that activates at a certain temp.
Karlm
NAXJA Forum User
- Location
- Antioch, CA
I've been reading about the fan over-ride switches, but I haven't ever found a good write up on installing one. I really would like a switch that over-rides the siganl from the ECU but does't replace it, so that I can switch the fan on, or I can leave it in normal operating mode. Does anyone know how to do this. I can splice wires and whatnot well enough, but I'm a little ignorant when it come to electrical current flow and diagrams. I wish I would have made it to my college electronics class a little more often 
I still got a C though .
I still got a C though .check your raditor for dirt inside and out a good washing with a hose on the out side may do some good even more so if you have ac because of the evap in front dont over look your water pump. iv talked to a lot of xj guys and they all seem to say the same thing 195 t stat , gdi 3 row rad , and a good hi flow pump
Karlm said:I've been reading about the fan over-ride switches, but I haven't ever found a good write up on installing one. I really would like a switch that over-rides the siganl from the ECU but does't replace it, so that I can switch the fan on, or I can leave it in normal operating mode. Does anyone know how to do this. I can splice wires and whatnot well enough, but I'm a little ignorant when it come to electrical current flow and diagrams. I wish I would have made it to my college electronics class a little more often
I haven't found anyway to change the 218* ECU electric fan switch without some type of re-wiring. I think the dealership could do it, but there are no aftermarket ECU programmers that I know of for the fan on/off code. That's why I had to go the toggle route. FYI, new 3-row radiator and flowkooler waterpump I installed about 6 months ago.
Majo
NAXJA Forum User
- Location
- Watertown, NY
just becasue its' 3 row doesn't mean it's the best, I've seen some 3 rows pawned off that have a lower flow rate then some heavy duty 2 rows.
Karlm
NAXJA Forum User
- Location
- Antioch, CA
Planetcat said:
I'm looking at going the toggle route, but what I'm curious about is whether or not this completely negates the factory system for turning on the fan. I want to be able to toggle the fan on if I want to, but otherwise have it run as normal. Is there a way to run a toggle that adds power from an external source for when I want the fan on, while letting the ECU send power to the fan if I don't toggle it on? I hope this is clear, but I'm really not good with explaining electrical stuff.
tireroastin93XJ
NAXJA Forum User
- Location
- Sedalia,Mo
I put a 160* in my 93. It would climb over 220* in the summer w/o the a/c going so I changed it and flushed the system really well. It's not an oem but it works. Now I run about 170* and about 200* in heavy traffic in the summer and I still have good heat now.Runnin'OnEmpty said:
Mike Harris
