What kind of 5w30 did you use? If it was cheap run of the mill dino, I wouldn't count on it to hold up to the heat the air cooled engine can dish out.
I like Chevy and Valvoline.
'13 Cruze, 1.4T, 112K
'85 GMC C3500, 454, 130K
'82 Mercedes 300CD, OM617 turbo, 167K
'67 Suburban, 350, 331K