Flashing red light and temperature guage needle seems high

[Bertsbus]

Hi, wondering if anyone can help.... The red flashing light which usually goes out after a few seconds of engine switch on is staying on, so far we've replaced the sensor with one from vw heritage and checked all the coolant levels which are fine, what else do people suggest ? Also we're a bit worried about the temp guage needle as it seems to go quite high before falling again - it gets to midway between the light and max and then drops back to middle or just slightly to the right ofnthe middle - we're not sure if this is normal or not - it's never overheated and always seems to drop back, just wondering if its normal that it goes that high first. Any advice would be much appreciated! Thanks

[CovKid]

Could be a blockage somewhere but have you checked to see if your fan is actually working? The fan switch may be faulty.

[tricksta77]

I had a similar problem when I first got my doka, was worried about overheating so checked the coolant level sensor in the expansion tank, quick clean up with some fine emery paper and a cloth and connected back up, no difference! Hmmmm

Followed wiring around visually and found dodgy looking earths everywhere, another few minutes of rubbing down with emery cloth and a little copper slip on the bolt threads and success!!!! Bad earth, I'd check them first and then check wiring for bad connections before spending more cash on new sensors.

I'm still learning but this a relatively quick and easy way to improve things, I even noticed a substantial improvement to the starter motor and starting in general.

Just my 2p

Rich

[AdrianC]

Hi, wondering if anyone can help.... The red flashing light which usually goes out after a few seconds of engine switch on is staying on, so far we've replaced the sensor with one from vw heritage and checked all the coolant levels which are fine, what else do people suggest ?

What happens if you disconnect the coolant level sensor (I presume that's the one you replaced?) in the tank, then connect the terminals in the plug together? If it still flashes, you've got a problem in the wiring or the circuitry in the dash. If it goes out, your prob is the sensor or level.

Also we're a bit worried about the temp guage needle as it seems to go quite high before falling again - it gets to midway between the light and max and then drops back to middle or just slightly to the right ofnthe middle - we're not sure if this is normal or not - it's never overheated and always seems to drop back, just wondering if its normal that it goes that high first. Any advice would be much appreciated! Thanks

That sounds normal - I presume you can hear the fan kicking in when the gauge starts to drop again? (Assuming it's not just dropping because the traffic started moving...)

The thermostat sets the lower end of the "normal" range, the fan switch sets the upper end. There's about 10-15deg between them, plus lag from the length of the cooling pipework. The gauge sender's in the engine bay, the fan switch is in the rad at the front.

[Bertsbus]

Thanks everyone for the advice, few tasks for the hubby at the weekend I think ! We hadn't even thought about checking the fan... We have so much to learn