Does anybody have experience with the 3.8 engine Low coolant Sensor light coming on, and although the sensor has been replaced twice in a year, the low coolant light still comes on from time to time and there is no problem with the coolant being low.

it sounds like it could be a wiring issue....is it actually ruining the sensors?

I have the same problem. I believe the sensor is on the front of the radiator just below the radiator cap. Can anyone confirm?


I cleaned and re-connected the plug this morning, with no apparent improvement. Does it take some start-stop cycles to clear the alert?


I guess the next thing is to remove and clean the sensor itself. Does anybody know if this is likely to work or if I should just get a new sensor? How much isthe sensor? That sucks that you've replaced it twice! I don't know exactly how this sensor works, but you've got to wonder if the problem could be elsewhere.Edited by: MrBSS

I left the car with the Dealer when I came north for the summer. The last word from them was they would look at the wiring harness as the source of the problem. The car is back in my driveway, and my grandson has driven it. Seems to be cured.

For those who may be interested, I think I fixed mine Saturday ('97 Ultra). The sensor just snaps into the radiator,held with two plastic clips. It is inside a clear plastic dome, which might imply optical sensing. Anyway, I took off the dome, cleaned it and the internals with contact cleaner, and reassembled it using dielectric grease.


So far, no "low coolant" message.

Well today I got a low coolant message again. Guess I'll examine the wire harness, and if that appears good, I'll order a new sensor.

Cleaned the whole system (overflow bottle had terrible "bathtub ring"), replaced all hoses and the low coolant sensor, filled with new Dexcool. So far, so good.

so you think that it may have been due to some dirt in the system?

Well, I don't really know. When I first cleaned the sensor, it worked for quite a while. I could have cleaned it again when I changed the coolant and hoses, but I didn't want to take the chance that I would again have a problem, so I just replaced it.

oh, i understand

This may not work but you could check the sensor for what its telling the computer..


disconnect the sensor.. see if the problem remains permanently .. then you know its looking for a value there. Then short it out to see if it goes away permanently.. THen you know it is still in the sensor..


If neither works permanent the problem is somewhere back from there. PCMs are flakey sometimes whenvoltages or grounds are loose.