Valve Depressor

Fig 1: Identifying Valve Depressors

Courtesy of VOLVO CARS CORPORATION

Valve depressors without CPS  -functionality (C  amshaft P  rofile S  hifting) have a coating of DLC  (D  iamond L  ike C  arbon).

It is the tops of the valve depressors that are coated with DLC. The layer with diamond-like carbon structure has a depth of 2μm, is very hard and has self-lubricating properties. The surface reduces the friction against the camshaft lobes and thus gives lower fuel consumption and longer service life.

Thanks to very good adhesion and toughness the DLC-coating can handle very high loads. The change applies to valve depressors without CPS-functionality.

This means that it concerns depressors in position:

• Engine B6304T4 (Ulev2) Exhaust, inlet
• Engine B6324S4 (Pzev) Exhaust, inlet
• Engine B6324S5 (Ulev) Exhaust

If needed the DLC-coated depressors can also be used on older engines.