Coolant Temperature Sensor Testing

[weebur]

Since my XJ has over 140K I thought I would replace my coolant temp sensor and in the process do a head to head test with a NAPA Echlin premium sensor. I'd like some input regarding the numbers. The Jeep runs fine, except for crappy gas mileage. I haven't driven it yet because my steep driveway has about a 1/2" of ice on it.

I took out the original coolant temp sensor and replaced it with a NAPA premium Echlin TS3005.

Tested in the garage with a 43 degree ambient temperature.
Original: 23.56 k/ohms (cold) to 5.45 k/ohms. Maxed out after several minutes under the heat of a small light.
NAPA: 22.97 k/ohms (cold) to 2.29 k/ohms. Maxed out same as above.

The original sensor appeared to react quicker than the NAPA. I will see how the Jeep responds to the NAPA sensor.


Thanks for any input.

 

[winterbeater]

I searched "temperature sensor testing" and found threads with factory numbers. Sorry, can't copy and paste on my device.

 

[weebur]

I searched "temperature sensor testing" and found threads with factory numbers. Sorry, can't copy and paste on my device.

Thanks, I'll do the same tomorrow morning and see if anyone else has any input.

 

[Ecomike]

Test them in ice water and boiling water, 32 F and 212 F, then look up the factory ohm spec at those temps.

Year?

 

[weebur]

Test them in ice water and boiling water, 32 F and 212 F, then look up the factory ohm spec at those temps.

Year?

'97.

Thanks, I did find the factory specs and the new NAPA sensor looks OK.

 

[weebur]

'97.

Thanks, I did find the factory specs and the new NAPA sensor looks OK.

My specs are:
29,330-35,990 ohms @ 32F
640-720 ohms @ 212F

 

[kastein]

With a 97 there's just one sensor for the whole system, so as long as the gauge is reading reasonably accurately, that means the computer is using a reasonable value too and there's no real reason to replace it. Good to have a known good spare on hand, though.

 

[weebur]

With a 97 there's just one sensor for the whole system, so as long as the gauge is reading reasonably accurately, that means the computer is using a reasonable value too and there's no real reason to replace it. Good to have a known good spare on hand, though.

Thanks, after a tuneup I was playing with my scanner checking fuel trim and O2 sensors and since everything looked OK I wondered if maybe the CTS was out of range I might get a boost in MPG; no big deal though, like you say I'll have a known good spare in my toolbox.