Weird Low Coolant

[Dan Hunter]

I know this sounds suspect but I am asking this for a friend.

Is it possible to have a low coolant sensor fail and give a false indication? She has the reservoir slightly above the proper full line but it's giving a low coolant indication. Prior to filling it today which took less than one quart, it had previously flickered the low coolant light but came on steady yesterday.

Externally it shows no leaks and doesn't steam on startup.

I'm thinking it's a bad sensor. Anyone?

 

[guybb3]

Mine did that a while back and then fixed itself.

 

[Dan Hunter]

I need more self fixing stuff. I'm going to ask her to try unplugging it and evaluating it both connected and jumped.

 

[Odlaw]

Sounds like the coolant sensor is unhooked or bad. Check passenger side, back side of rad about half way down - small, single wire connector.

 

[Capt K]

Mine shows up on the DIC every once in a while then disappears.

 

[6.5TD Burb]

Mine does the same thing when it's cold out. After driving a few minutes it goes out; doesn't do it in warm weather though.

 

[matuva]

What kind of coolant do you use ?

Mine was showing false when I was using water + water wetter. It goes back normal as soon as I put back green coolant + water wetter.

Also, while driving on bad roads or off road, it usually light up the low coolant light as the truck is being "shacked"

 

[625fireman]

The prob with the sensor is........it is a continuty switch so with some additives (water wetter) it coats the conatcts so it will give you false low coolant readings. You might try taking the sensor aout and cleaning it off and see what happens but it could be bad internally.

 

[JMJNet]

Still check for leaks. If it goes down less than a quart, there is a small leak. Watch for coolant drip in the morning under the truck. Is this diesel truck? or gasser?

 

[625fireman]

Still check for leaks. If it goes down less than a quart, there is a small leak. Watch for coolant drip in the morning under the truck. Is this diesel truck? or gasser?

:iagree:
Yep do this first. check to see if the water pump is seeping too.

 

[uniquediesel]

Is this diesel truck? or gasser?

Yeah, check for spark plugs, if present it's not a real truck