Volkswagen Workshop Service and Repair Manuals

Special tools, testers, measuring instruments and auxiliary items required

• ◆ Depth gauge
• ◆ Valve seat re-facing tool

Notes:

• ◆ When repairing engines with leaking valves, it is not sufficient to rework or replace valve seats and valves. It is also necessary to check the valve guides for wear. This particularly important on high mileage engines.

• ◆ The valve seats should only be reworked just enough to produce a perfect seating pattern. The maximum permissible reworking dimension must be calculated before reworking commences. If the reworking dimension is exceeded, the function of the hydraulic tappets can no longer be guaranteed and the cylinder head should be renewed.

The max. permissible reworking dimension is calculated as follows:

• ‒ Insert valve and press firmly against seat.

Note:

If the valve is to be renewed as part of a repair, use a new valve for the measuring.

• ‒ → Measure distance -a- between end of valve stem and upper edge of cylinder head.
• ‒ Calculate max. permissible reworking dimension from measured distance -a- and minimum dimension.

Minimum dimensions:
     Inlet valve 33.8 mm
     Exhaust valve 34.1 mm

Measured distance -a- minus minimum dimension
= max. permissible reworking dimension.

Example:

     *)     The max. permissible reworking dimension is shown as dimension "b" in illustrations for the reworking of valve seats.

→ Reworking inlet valve seat

→ Reworking exhaust valve seat