The 5-cylinder Audi has hydraulic lifters..... I owned an 84 4000S Quattro. The best driving piece of junk in the world. That car ate water pumps, alternators, batteries and allignments. It was carefully maintained and was too much trouble to keep, typical Audi of those years. It handled well, had great breaks and blew the fuel pump fuses as quick as I could replace them until I rewired the circuit. You're right about the engine lasting a long time, those cars couldn't run long enough to wear out.