>a.  test the compression 
>b.  squirt some (2-3 Tbsp) oil into plug hole
>c.  test the compression
>

This works best in engines with vertical cylinders, it's damned hard to 
really wet the full crown of a VW piston. You can also pressurize the 
barrels with shop air via a sparkplug adapter and listen for a hiss at the 
exhaust pipe if ex. valves aren't seating well, or a hiss at the intake side 
if inlet side. tim s.