A4 Quattro Wagon V6-2.8L (AHA) (1998)
Valve Seat: Service and Repair
Refacing
Notes:
-
Only reface valve seats enough until a perfect contact pattern is obtained
-
Before refacing, calculate the maximum refacing dimension.
-
If refaced dimension is exceeded, hydraulic valve lifter function is no longer guaranteed and cylinder head must be replaced.
Calculating maximum allowable refacing dimension
-
Insert valve and press firmly against valve seat.
Note: If valve is replaced during repair, use a new valve for measurement.
-
Measure distance between end of valve stem and top surface of cylinder head (four-valve head shown).
-
Calculate maximum allowable refacing dimension using distance measured and minimum dimension.
The measured distance minus the minimum dimension equals the maximum permissible refacing dimension.
Example
Note: If the measured distance is less than the minimum dimension, repeat the measurement with new valves, or replace the cylinder head.