Checking Valve Guide

Information 

Intake and outlet valves must not be reworked.

They can only be ground.

1. Check valves.
   1. 1.1 Check the stem and surface of valves for score marks.
   2. 1.2 If distinct score marks are visible:

      Replace valve.

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      Valve dimensions

      Dimension	Unit	Intake valve	Outlet valve
      Diameter a	mm	32.0 ± 0.10	28.0 ± 0.10
      Diameter b	mm	5.92 ± 0.20	5.92 ± 0.20
      c	mm	102.43	103.184
      α	°	45	45

2. > VAS 6079 - Dial gauge-2-  must be fitted.
   1. 2.1 > VW387 - Universal dial gauge bracket-1-  must be fitted on the cylinder head.
   2. 2.2 > VAS 6079 - Dial gauge-2-  must be inserted in the > VW387 - universal dial gauge bracket-1-  .

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   Dial gauge on cylinder head

   Information 

   If the valve is replaced during repairs, perform measurement using a new valve.

   Different valve stem diameters: Only use intake valves in the intake-valve guide and outlet valves in the outlet-valve guide.

3. Determine the valve tilt play.
   1. 3.1 Insert valve -1-  into the valve stem to be checked.

      The end of the valve stem must end flush with the valve guide.

   2. 3.2 Tilt the valve -1-  away from the dial gauge -2-  with your hand. -arrow A- 
   3. 3.3 > VAS 6079 - Dial gauge-2-  must be attached and set to zero.
   4. 3.4 Tilt the valve -1-  towards the > VAS 6079 - dial gauge-2-  (-arrow B-  ) and read off the value.

      Wear limit: 0.8 mm 

   5. 3.5 Repeat this on all valve guides to be checked.

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   Checking valve tilt play

4. If the wear limit is exceeded:

   Replace valves and repeat the measurement with new valves.

   Information 

   Valve guides cannot be replaced separately.

5. If the wear limit is still exceeded even with new valves:

   Replace cylinder head.