flashing coolant/temp light

[Dan_GTi8v]

I have an aum in my mk3 and the dash coolant light is flashing. Not sure what the coresponding light is in the mk4 but im guessing its the same what could be the causes? It has coolant in it and the wiring all looks ok. It flashes as soon as I start up so dont think its the engine temp as it doesnt have a chance to heat up. any ideas?

[richw911]

Dirty contacts in the coolant bottle which makes the ECU think there is no coolant in the bottle.

Clean them or replace the bottle for £15 for a brand new one 

[Dave_IOW]

i had this problem and cleaned the sensor, 12 months on, still fine 

[Dan_GTi8v]

sensor is clean, it stopped flashing for a bit when I took it for a test drive, but came on again a few mins later

Does the routing of the radiator pipes make a difference? I wasnt sure which way to put them on the mk3 rad so I have the top right hose going to the top of the rad and bottom left hose going to the bottom of the rad. Its an aum and a 8v GTi rad, is that the right routing and would it make a difference?