I wonder what kind of noises that engine was making when the owner brought the car into the shop!
Reminds me a guy I kind of knew... who had a Jetta GLI back in the day. He drained the manual trans fluid... dropped in two new liters of gear oil... when he went for a test drive the car couldn't move out of his garage. The clutch would just smoke and spin in place. Turns out... he filled the flywheel inspection hole/cap with the two liters of gear oil and NOT thru the speedo cable as was the case with those Jetta/Golf MkII's! lol That was a pretty costly lesson!