Compression (2.8L VR6, Engine Code AES)

Ensure battery is fully charged. Engine oil temperature should be a minimum of 86°F (30°C).
Turn ignition off. Remove radiator grille. Remove right and left side securing bolts for lock carrier. See Fig 1 . Tilt lock carrier with radiator toward the front.

Fig 1: Removing Lock Carrier Bolts (4) & Tilting Lock Carrier/Radiator Forward (Engine Code AES)
Courtesy of VOLKSWAGEN UNITED STATES, INC.
Disconnect heater element connector. Remove intake hose between upper air cleaner and throttle valve control module together with PCV valve.
Unclip cover for ignition coils with power output stage. Disconnect harness connector from ignition coil/output stage. See Fig 2 .
When performing compression check, throttle valve should be open. Check engine mechanical condition with a compression gauge and remote starter to crank engine. See COMPRESSION SPECIFICATIONS table.

Fig 2: Locating Ignition Coil/Power Output Stage Harness Connector (Engine Code AES)

Courtesy of VOLKSWAGEN UNITED STATES, INC.