The valvetrain on the N52 introduced in 2006, used 5 mm valve stems on both
the intake and exhaust. To
increase durability, the exhaust valve stems were increased to 6 mm from 6/06
production.
All of the new NG6 engine have adopted the 6 mm valve stem for the exhaust, the
intake stem remains at
Before A/C efficiency test, satisfy following conditions:
1. Provide a MoDiC or DIS. Safeguard electrical system integrity by checking
the fault memory (no faults
in the fault memory).
2. Provide a thermometer with separate gauge.
3. Perform the test in a suitable work bay with an ambient temperat