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alternative temp sensor location for 4.0L?

1180 Views 12 Replies 4 Participants Last post by  jeepflexitude
dose anyone know if there is any place other than the stock location that I could put a coolant temp sensor on a 93 4.0L?

also, do I need to keep the stock temp sensor hooked up to the computer for the engine to run correctly? if not, then I could just put the new sensor in it's location, but if I have to keep the stock one hooked up the the computer, then I need to find an alternative position for the new sensor.
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Looking at my wiring diagram for a '93, doesn't look like your ECM is connected to your heat sensor. I mean, if you think about it, the absence of that sensor shouldn't effect anything. I've had my Jeep almost boil over and my ECM didn't even blink.

Easy way to tell: cut the wires. If it still runs, you're golden.

Also, if you're using the same stock gauge for your new temp sensor, stands to reason it's sending the same info the stock one is, no reason it shouldn't be able to replace the stock one.

Just my half-drunk ramblings.

--Hardy :D:

so the computers on the 93's don't use engine temp to go from "open" to "closed" (or closed to open, whichever it is)loop modes once the engine is warmed up?

I'm going to ditch the stock temp guage (and eventuailly others) the new guage that I picked up uses a capilarry (sp) tube that will run from the engine to the guage(no wires at all, except for the light)

guess what I'll do then is just unplug the stock temp sensor, and see if it runs correctly. if it dose, then I'll just put the new temp probe in the stock sensor location.
It's possible, but I thought there was a seperate temp sensor for that. Could be wrong. Stranger things have happened.

Sounds like just disco'ing it and running would be the easiest way to tell.

Are you replacing the stock gauges out of hate for plastic? That's why 85% of my dash didn't get put back in after I rewired my Jeep. I found this nice metal frame under all that plastic that I can rattle-can black and make look better than my crap plastic dash ever dreamed of being.

So I spray painted the white covers of my gauges matte black and, viola, new dash. Next step is CJ gauges.

--Hardy :D:
On 2005-11-23 08:52, TrojanYJ wrote:

Are you replacing the stock gauges out of hate for plastic?

--Hardy :D:

well, yes and no. I'm not a big fan of the plastic, but also, not all the the guages work, and the ones that do aren't accurate, and only work when they feel like it.

actuailly, I've got some left over diamond plate aluminum from doing my rocker pannels, and I'm playing with the idea of making a custom dash pannel out of that, of course, painted flat black t match the color scheme that I'm shooting for.
Sounds hot. My speedo is pretty finicky, but it increases the resale value! :bigthumb:

I mounted my amp where my glove box was and put a piece of diamond plate up to cover the hole and mount the switch for it. Haven't got around to painting it, it just looks too *bling*, makes me giggle.

Debating hacking it up for two switch panels to go where the old radio and heater controls were and mounting the amp somewhere in the back... but then I'd have a gaping hole in my dash...


--Hardy :D:
well, scratch that idea, :wall:
I disconnected the temp sensor and started the engine, just to see if there would be any problems. well, as soon as the engine fired, the "check engine" light came on, and staied on until I plugged the temp sensor back in. it was starting to get dark when I did this, and I didn't have a light with me, so I didn't get a chance to look for an alternative spot for the new temp sensor.

I did have a thought though, I know it's possible, but how well would it work if I were to remove the stock temp sensor, install a "T" fitting, and put both sensors in to the "T"? would doing that effect the accuracy of the sensors verry much?
Obviously as you found out you have to keep the stock one plugged in. And using a T fitting will not work there. I tried that too on my XJ, but the gauge didnt read because the coolant wouldnt get up there.

So, there is a place you can put it and it works great. Cut a 2" peice of of your lower radiator hose out, then replace it with a 3" peice of round tube that fits inside it. Before you put it in, drill and tap a hole in the middle of it to screw the fitting for the tempo gauge, and put it in and clamp the pipe in there. And there ya have it. I did it to my XJ and it works perfectly! If i can find the pics ill post them up. :bigthumb:
Well i found them..that didnt take long lol.

I forgot, you will have to cut that spring thats in the hose too. So here are the pics.

Cut a chunk out of the lower hose and the spring...

Drilled and tapped the peice of tube (doesnt need to be threaded on the ends, just had it laying around)...

The censor threaded into the tube, perfect fit...

Here it is all done, pipe clamped in and hooked up...

*** Dont forget to teflon tape the threads on the fitting to seal it up too***

Hope this helps! :bigthumb:
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Take a look at these.
well, I got the sensor installed. I ended up cutting one of the heater coor lines(the one that comes off of the water neck next to the stock temp sensor) and put in a "T" fitting, and putting the new temp sensor into that. the guage seems t be working, but I now think I may have another problem.

after I had the new guage hooked up, I started it and let the engine warm up so that I could compare the new guage against the stock guage. well, even after sitting a wile, and then going for a short trip, the new guage barely moved above 130 degrees F. and since the 02 cherokee that we used to have ran at 210*F,(it had the 4.0L also, just newer.) I'm thinking that I need to get a new thermostat.
just wandering, what temps do your jeeps (4.0L) run at? dose the 210* I mentioned above sound correct?
If you havent change the thermostat out at all, or put in a stock replacement, then yes that is the right temp. Now you can get a lower degree thermostat, i got a 180* one, and i hooked my electric fan to a switch and have it running at all times, and it only gets up to 160*. So i guess if i were you, id jsut go buy a 180* thermostat and go with that.
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