Coolant Level Sensor question

Hi,
For the past months the red bulb in the water temp gauge keeps flashing at random times. Coolant is OK and no leaking exists. Two days ago I changed the thermostat and since then it stopped blinking.



So the question is, apart from the coolant expansion tank, is this bulb taking readings from another sensor?
Just to mention that the sensor on the coolant tank is the 251919372A, and I have changed this two or three times already, because it is bleeding coolant after some time. The new one from veedub site is also currently bleeding…

Cheers,
George

I had the same trouble with aftermarket level sensors leaking, Eventually I bought one from vw for £17 I think it was. The flashing turned out to be the coolant level sensor relay, if you have had leaking level sensor it could have let the water travel through the wires all the way to the relay. Mine had water in it.

Tomorrow I am taking the car to remove the dashboard as the MPG is not working as well. I will let you know....

the relay is 42/43 above the fusebox, pull it out and see if issue stops. the red light is also overheat warnign which is fed from the coolant temp sensor, if it or its wire shorting out intermittently this could cause the issue as if the short is only occuring for a second or so it wont be enough time for the gauge to react as its damped

Finally it was a problem with the dashboard. Both MPG & coolant red bulb were fixed by soldering some parts I did not understand. Thanks for the info,

markageo said

Hi,
For the past months the red bulb in the water temp gauge keeps flashing at random times. Coolant is OK and no leaking exists. Two days ago I changed the thermostat and since then it stopped blinking.



So the question is, apart from the coolant expansion tank, is this bulb taking readings from another sensor?
Just to mention that the sensor on the coolant tank is the 251919372A, and I have changed this two or three times already, because it is bleeding coolant after some time. The new one from veedub site is also currently bleeding…

Cheers,
George

My Rivage has just started with a flashing coolant light even though theres no problem. I think its just water on the sensor after I cleaned the engine bay i'm going to wait for it to dry out and check tomorrow,But also I see from your pic your car has almost the same milage as mine , my cars got 202,300 miles.

Mine is in kilometers, but nonetheless, this has been happening for the past 20k kilometers. Before fixing the dashboard, the light was not working at all, whether the coolant level sensor was connected or not, in the water or not.

Now it works fine, but unfortunately I still get some random red bulbs for no reason. I will head to checking the coolant temp sensor as rubjonny suggested.