Mystery coolant leak

[badboi4lyff]

Hi.. I have a 2004 A4 1.9tdi sport..

Every other day I am having to top up the water and coolant.. As far as I can see, the water seems to be going missing from the water expansion tank as there is always a residue of antifreeze under it that has stained the bottom parts a rusty colour..

I have replaced the thermostat and water tank and cant figure out what the problem is..

Also is there anyone in Manchester area with vag-com, all i need doing is the auto doorlock..

Any replies are much appriciated..

[robert23]

Firstly can i ask have you checked the oil, if its a creamy colour thats where the water is going. My last audi was the A3 2.0TDI and i also had a mystery coolent leak. I had audi out to me and they pressure tested the system and told me i wasnt loosing water, although like you i was topping it up every two days!! This continued so i took it into audi for them to take another look, they started the engine in the workshop and after smashing the conrods and pistons to bits they realised it was the head gasket which had gone. Fortunately it was still under warrenty and they had it 6 weeks costing £2500. Just be careful and check its not the head gasket!!!