UK-POLOS.NET - THE VW Polo Forum

Hi Guys,
I'm having some issues with my 2006 GTi
Basically on a cold start sometimes the coolant light and comes on (with a beeping alert). This doesn't happen all the time, just sometimes.

If this happens I check the level in the coolant header tank... Which I way way below the minimum mark (which is obviously turning on the light in the car).

This is where it gets strange....
If I then drive the car around for a short distance (eg 1/2 a mile) and look at the header tank again, it's back up to maximum! This is very weird as the correct amount of liquid must be in the system somewhere??
So then if I stop and restart the engine the light doesn't come on and everything’s normal again.

This is my experience in trying to sort this so far ...

# It needed a service so I reported the issue when it went in. VW said they had pressure tested the system, checked for leaks, topped up coolant and found nothing.... So they didn't fix anything really.

# Took it back (2days at VW this time). This time and they diagnosed the fault as the header tank, which they replaced.

The problem still occurs though. I've got it booked in VW on Monday morning (they want it for 3days??) to find and fix the fault.

Can anyone offer any advice, or has anyone else experienced this problem?
I really want to get to the bottom of this, it's very annoying and I’m also tired of driving the dealers Fox loan cars

Take a look at these from the last time it happened....
http://www.photodump.com/danm/Image001.html
http://www.photodump.com/danm/Image002.html

Cheers


Dan

That's extremely low!

May be a tiny leak from somewhere not very visible? Not really sure on that though! I doubt there's a headgasket problem!

When your car warms up, the coolant always tends to rise slightly, but It's strange that it would rise that much from almost empty! Tricky one that, hope VW don't rob you of too much money!

Believe me they wont be robbing me of any money.... warranty

I cant see how would be a leak though. As the level goes back up to max after a short drive... the coolant must be in the system somewhere

air lock in the system and needs bleeding?

perhaps??? ... Hopefully will get it sorted on Monday!

thats def a air lock!
i had the same problem with my first gti

i sorted it myself cos vw would just end up replacing parts forever lol

basically i just undid the expansion tank, started the car, left it running til it got warm and the coolant was up to temp, tightened it, then it was alright from then!

hope this helps

It seems pretty obvious from a distance, but its strange that the VW garage have fallen into this trap without there being another plausible reason. I believe quite a few older cars, mainly Fabia, have been having problems with both their header tanks leaking (need replaced) and the low coolant warning sensor needing the fluid to be up to the maximum - in cold weather (not purely fluid shrinkage with temperature) and some level sensors getting curded up even when correct mix is in the system. So maybe some of this is why the dealer has not got it right first time - still looks like they have ended up getting some air into the system though - as said already. Also, as said already, if dumping the car at the dealer is a waste of your time, personally I'd just buy a container of G12+ and top it up when cold and low - just add neat G12+ first time), then as suggested run it with the pressure cap off until warm - ie along the road so that the waterpump is moving the liquid round quicker than at idle - heater on hot (just in case it helps circulate the liquid) - just don't go overboard and boil the liquid out the top and all over your engine bay. I find sometimes its easier all round to try and sort the small problems yourself.

Thanks for the advice guys... I'll let you know how I get on.

Just one caustic comment that I once needed to make to a Ford dealer - "a car will only last so many years, so many miles or so many visits to the garage" - try to be economic about how you use your car's "dealer lifes" up. Garages hate to hear this sort of thing - but my experiences over the years tend to make me believe that there is quite a lot of truth in this!!