hi, i dont know if this is a common fault or not but i am converting my mk4 xr3i to rs turbo at the moment an when i took the efi off and inlet manifold off the gasket between manifold and head had failed around the manifold coolant hole and was leaking water into number 2&3 cylinders.

im not sure if this could be why your gas test showed a positive reading and compression read fine, myn said that both were fine though as i checked them 2 weeks before starting conversion