Golf MK3 Coolant Level & Temp Warning light

[andyc567]

I have 1997 'R reg' MK3 Golf 1600 which has started to randomly flash the Engine Temp & Coolant Level warning light.
It is the far left hand light in the long row of warning lights on the instrument panel.

This light flashes for a few seconds when the ignition is switched on as a self test, and then goes out. Thing is, it then come back on at random intervals, often when the engine is still cold, and also when driving along normally.

As this light is a dual purpose warning (why do they do that) indicating both engine temp and also coolant level, it is not clear why it is on/flashing ?

Engine temp is fine, sitting right in the middle of the normal zone, and the the coolant level is spot on. Engine runs absolutly fine to..

So, our guess is a sensor somewhere, but has anyone else got any other idea's ??

Hope to Vag-Com on it, but in the meantime, any help or idea's would be greatly appreciated.

Thanks

[Vagnum]

i don't think Vag com will bring up a fault code for that, could be a fault with the sensor in the header tank, oil/rust contamination causing sensor to read as a closed circuit thus bringing the light on. hope this helps.

[andyc567]

i don't think Vag com will bring up a fault code for that, could be a fault with the sensor in the header tank, oil/rust contamination causing sensor to read as a closed circuit thus bringing the light on. hope this helps.
Spot on, Vag-Com does not produce any errors, nothing at all !

Tried disconnecting the plug in the header tank, and the light still flashes.

Even tried shorting it out with a split pin, and guess what, it still flashes.

We are a bit stumped..