I have a 1996 XJ Sport RHD (from Japan). Temp Sender was falling apart, but when wiggled gave a normal temperature on the gauge (100ish Celsius). I just swapped out with a new sender from NAPA. Now the Gauge is reading about 112 C. Wondering, since my gauge is in Celsius instead of Fahrenheit, if I might have needed to order a different sender. 112C is hot, 95-100 would be approximate expected temp for the 200-210 F range I should see. I drove it, consistently stayed at/around temp in the picture. Also posted a pic of the old sender.

 

I'm thinking Celsius and Fahrenheit Jeeps came with the same senders just different gauges, but that is just a guess. But you could've gotten the switch for an idiot light by mistake which would give a different resistance reading. Do you have the part number for the sensor you got?

 

verified at NAPA, before leaving with the part that it was the correct sender. Part #: MPE TS6685SB

 

You seem to be assuming that the gauge readings you were getting with the old sensor were correct, even though it was falling apart, and that the readings with the new sensor are wrong.
Perhaps shoot the area around the sensor with an IR thermometer or take it out and put it in a hot water bath while wired up and see what you get.

 

true, I am assuming….bad idea. I’m cheap and don’t want to buy a IR thermometer, so I am trying to find a place or person that has one I can borrow. I’ll post back with what I find. Very possible it’s been running hot for a while.

 

so, I went a different route with the same goal. Went to Midas, mechanic there I trust, he hooked up an OBD-II reader. Even though gauge shows 112C/230F, computer shows actual fluid temp of 94-97C/204-210F. So, it’s most likely the gauge, or the ohms on the new sender. Either way, it’s doesn’t appear to be over heating. BTW, didn’t charge a dime to hook up the OBD-II and verify the temperature.

 

Just so you know...the reading you got from the obd2 reader is off your sensor in the thermostat housing. The computer does not monitor the small sender that you replaced...it only feeds the gauge

 

I guess that’s what I was trying to get at. The sender and/or the gauge are giving a bad reading(but doesn’t matter). According to the OBD2, the temp is spot on and Tstat opens at the right temp. Or were you suggesting there may still be an issue? I’m new to Jeeps, but hoping I don’t have an issue with the cooling system. The fact that the computer says the temp is 205ish should mean it’s ok, no matter what the sender and gauge say.

 

Keep in mind that the temperature the scan tool is telling you is only as good as the temperature sensor that's feeding it (the old garbage in garbage out problem)
that's why if you really want to know the temperature you use a decent ir thermometer..

BTW: if you're going to own a Jeep that's got OBD II you really need to buy a scan tool. Driving off to the car parts store doesn't really work if the vehicle is undrivable. They don't cost very much.

 

Do you have a scanner you use or would recommend. Searching, the prices/reviews seem all over the place…would be interested in advice from someone who has one.

 

Actually I have 3 if them; one that lives in the xj, one in my 4runner, one in the home tool box. I bought them all before the Bluetooth thing arrived so can't comment on that.
BT aside: at a minimum. ..
-You want something that tells you what the code is, not just something that gives you the number- you want it to give you live data... O2 sensors, temps, map, fuel trim, throttle, rpm ,etc etc.

They pretty much all will clear codes

I like scan tools that are powered the OBD port rather than batteries., ,No leak fears
You should be able to find something for $50 or so. They've gotten a lot cheaper over time, the first one I bought was $250.
That's my answer, you're going to get about 1000 others

 

This Jeep is going to be great….or end my marriage….haven’t figured that out yet. The wife isn’t thrilled about the money I’ve put into it so far. But, got it cheap, (took over payments for my mom when she retired from the post office, about 2K). Was really hoping to be “happy” with the OBD2 reading, but now you have me questioning that….and the IR thermometer ratings are all over the place also. The things that worry me, are the things I know nothing about….I can spend $20 on an IR thermometer or scanner, or hundreds on them…and the reviews on all of them suck. They are all the Best thing since sliced bread, and worst thing ever….depending on who reviewed them….

I should add though, I had the cap open on the radiator, and when the scanner sad it was at 195, it started sucking fluid down. Pretty good indicator that the tstat opened at that time and the temp rose too, and stayed at 205. But, an actual temp reading would settle it for sure.

 

So, finally found an IR thermometer, and the results are confusing… temp at TSTAT is 205F, but temp at the sender is 230-240F. Coolant flow issue? Maybe need to flush the block? Any thoughts?

thanks

 

I had some problems with a faulty sender a while back and checked multiple points with an IR gun and I believe 240ish is what I got at the sender as well. I think things just get hotter back there. I'll try to find my thread and see if I'm remembering correctly.

EDIT: The reading I got was 247, so your readings should be fine.

 

excellent! Thanks! I was wondering if it was just a thing where the fluid gets hotter as it works its way through the block. Sounds like it is!