1986 Jetta Coolant level sensor

[Loaf]

I just replaced the coolant level sensor in my 1986 1.6D Jetta. The old one had a crack in it that was allowing coolant to leak out and drip down the expansion tank. New sensor cost $7 and took about one minute to replace. Bam- no leak.
I though I was winning.
Except...the red light in the temp gauge is flashing. With the old sensor, the light only flashed when the coolant level dropped below the minimum mark. With the new sensor, the coolant level is just above the minimum mark on the tank when cold and just below the max mark when warm and I still get the flashing light. The light will go off it I just cycle the key to off then back on once the engine is warm but I'm not a fan of doing that. I want it to work right.

Any Ideas?

 

[compu_85]

Is coolant covering the probes of the new sensor when the system is cold?

-Jason

 

[Loaf]

Yup, coolant is covernig the probes.

 

[Loaf]

A few months later, and still no coolant leak. I have not got around to replacing the sensor, I just call it the "It's All Good" light. Is everything running OK? Yup- flashing light in the temp gauge; we're good.

 

[T-Roy]

It is an extremely common issue on MK2 cars.

I've been daily driving mine for the last 3 years and it goes through fits with the coolant light flashing.

There really is no ryhme or reason to it, seems to be completely random.

The crappy thing is, once it starts flashing, it takes a key cycle to reset it and 90% of the time it will just start flashing again within a minute.

I haven't bothered to replace anything because it isn't that big of an issue, I know it has plenty of coolant in there, I still check the coolant every once and a while though.