Seat Leon TDI PD 150 engine is giving me a warning light whenever I start it up. The red light on the temp gauge flashes and I get a triple beep warning noise too. Turning the engine off and back on seems to sort it. The manual says it's either low coolant or one of three fuses. Checked all these; fuses are fine and the coolant level is spot on. However I did notice that the coolant reservoir cap was loose.

Am I right in thinking this should be done up tight? And might this be the source of the bogus warning?

Cheers,

SC

Yes it should be tight. Has tightening the cap stopped the warning?

Try searching or posting on uk-mkivs.net if it doesn't.

Cheers.

Not started the engine yet – will find out tomorrow morning.

I'm assuming the sensor measures pressure which would be artificially lowered by loose cap.

I get this warning on my MkIV Golf GTI when it's cold. I know it's a different engine, but that MkIV forum diagnoses it as a corroded sensor in the coolant reservoir. New reservoir (and integral sensor) apparently fixes it…

Sounds familiar zokes. Despite the different engine, I'm sure the cooling system components will be the same.

I'll see how it goes for the next wee while and then look at replacing the reservoir.

Cheers for help.

Yes, apparently it starts off only doing it when the weather's cold, then gets more frequent. The only way I found to shut it up is to give it some beans as soon as you start it to get the coolant to circulate. Not sure how good that is for the turbo from cold though…