Hi Anthony,

We had the same issues with a VAG 2.0 TDi, first changed the filter head water to oil cooler, few hundred miles and oil in header tank again, then head gasket few hundred miles still same, although I had the head pressure tested when the head gasket was done I put another head on it and that cured it. Theory being when head is sent for pressure testing they dont put 110c coolant through it so sometimes the crack doesn't show up when cold?

Rob