Forum Discussion

inky's avatar
inky
Explorer
Jul 02, 2013

Low Coolant sensor

I have a 1991 Beaver with a 3116 Cat engine. My low coolant alarm and warning light come as soon as I turn the key. The coolant is full. How can I check to see if the sensor is the problem.

Thanks,

Joe

10 Replies

  • The sensor is basically a switch. It is either normally open or closed, which makes it easy to bypass. If you remove it you should be able to see a manufacturer's name and maybe a part number. I have had pretty good luck with RockAuto.com when I look up a part using just the part number. Once you know exactly what you are looking for, it should be easy to find another, cheaper, source for the part.
  • Diplomat Don wrote:
    inky......Remove the sensor and use a Scotchbrite pad or something similar on the metal sensing part of the sensor and see if it works. Sometimes these sensors get crud built up on the sensor and won't read properly. This was an issue on some of the newer models.


    X2 That is what I would try first. Catch the coolant in a container when removing the sensor. Bill
  • Be sure with the 3116 to have valves adjusted and injector timing checked at regular (like 30k mi) intervals. Check injector sync if engine lopes too badly at idle.
  • inky......Remove the sensor and use a Scotchbrite pad or something similar on the metal sensing part of the sensor and see if it works. Sometimes these sensors get crud built up on the sensor and won't read properly. This was an issue on some of the newer models.
  • I was able to find a part number for the low coolant sendor. I have a Gillig chassis and it's a Gillig part number. Am I forced to buy this part only from Gillig online? I was hoping to maybe buy it locally.
  • The engine never gets a chance to warm up because the engine will shut down in 15 seconds after the alarm goes off.

    Joe
  • Returned after a 7000 mile trip and check engine and alarm went off with a code stating low coolant. Cummins found a bad censor in bottom of overflow tank. Tech hooked computer and found problem. With computer hooked up he jumped censor. I might not want to cross wrong wires in it. Never checked but you might find that there is only two wires. If that is the case I think it would turn off alarm and lite. Try it and save your self $400.00. Let us know how you made out. Rob
  • Does the light and alarm go off when the engine warms up?