Constant Red flashing coolant light...

[GaGti]

....And boiling water, Started flashing yesterday as i was stuck in a que of traffic on the M4. I am loosing water, but seems to me im loosing it from the coolant container as it boils over.
The radiator does come on but not as often as id like, also my temp guage sits where it usually is, nothing seems unusual there.
The car was low on oil, i had to add 2 ltrs yesterday.
I just dont know where to start...I have to use the car tomorrow as im on a Course for work, ill just have to take water with me to top it up.
Im thinking thermostat or head gasket, but head was changed 4000-5000 miles ago tops.

Any ideas?

If someone could also tell me where the thermostat is situated it would be much appreciated



Thanks in advance!

[herbster]

Thermostat is in the water pump almost, the bottom hose goes to a flange with 2x 10mm head bolts, undo these and then presto there she is! Use a genuine part more reliable. Also i'd get a new cap, would'nt worry if its the head yet, they do tend to burn the oil if you let them get too hot, you need to keep a closer eye on it for the next few weeks, check it before you use it everytime!!
My temp sits about 3/4 all the time until I hit traffic, tried all sorts, not too worried as long as my rad fan keeps working, hope yours sorts itself out. 

[monzablue16v]

Try getting a new coolant expansion tank cap from VW might not be pressurising which will let it boil over usually the best thing to try for starters. Definitley cheapest and easiest anyway

[...joe]

yeah get a new 'blue' coolant cap. the seals knacker in the old ones and they updated the design slightly and the updated ones are all blue.

[Organisys]

I tried a blue one, one winter from GSF and it was rubbish!!!!!!!!!!! maybe genuine are better??

[monzablue16v]

Yeah the GSF ones suck

[Organisys]

bit like their bloody water pumps then, muppets.
 

[GaGti]

Thanks for the replys!

I forgot to say its a 1.8 16v engine

As the water boils it naturally releases itself thro the holes in my expantion tank, which is where i am losing the water.
What i am more worried about is the Temperature of the water, the fact it is absolutely boiling and my light keeps flashing.
It is pressurising with the cap i have,that doesnt seem to be the problem as it spews out water when i slacken it off.
There is no white froth in the oil and no steam from the exhaust, which is safe to say its not the head. Is there anything else apart from teh thermostat that I should look for that could be causing the problem?
The car is burning rich at the moment could that be a problem?
Also, Ive never had the car do this before, which is why i have no clue if its safe to drive or not >.<

* Bangs head against wall * Lol

[Gambit]

have you changed the thermostat yet?

[GaGti]

Update:

Upon inspection the water pump seems to be pumping as usual.
The thermostat is working correctly.

Today I drove my car approx 90 miles to work. I parked it up and around lunchtime the alarm went off, and found my battery was dead.
My Rad fan had stayed on when the engine was off and drained my battery. Anyone know a reason for this?
Had to use jump leads and get the car going again, before i left i had to add 2 ltrs of water into the car as it had boiled over.

Im guna take the car to VW tomorrow and see if they can diagnose the problem, im completely lost tbh