Expansion tank leak through the overflow

[Zsolt]

Hy everyone 

I am experiencing a problem with my audi. I have an audi from 2001, 1.9 tdi, 130hp

I am losing water through the expansion tank over the cap through the overflow. 

I have been at two garages and have changed the thermostat, water pump and expansion tank. Had done 2 pressure tests, 2 head gasket tests and some blocking fluid was put in it. Both garages sad that they can not foult it. Everything came out ok. I just don't know what to do or where to take it. 

Can somebody give me an advice. 

Thank you very much

[Trevor]

Hi....welcome to the Forum

It sounds like it could be the coolant pressure cap not holding pressure.

When they carried out a pressure test of the cooling system, did they pressure test the cap aswell?

Let us know what you find