Audi AMB Service Manual page 495

ENGINE 1.8 Liter 4-Cyl. 5V Turbo Engine Mechanical, Engine Code(s): AMB
NOTE:
When repairing engines with leaking valves, it is not sufficient to reface

valve seats and replace valves. Valve guides must also be checked for
wear. This is particularly important on high mileage engines --> Valve
guides, checking.
Valve seats should only be refaced just enough to produce a perfect

seating pattern.
Calculate the maximum permissible refacing dimension before refacing.

If refacing dimension is exceeded, function of hydraulic valve lifters can

no longer be guaranteed and cylinder head should be replaced.
Calculating maximum permissible refacing dimension
Insert valve and press it firmly against valve seat.

NOTE:
If valve is to be replaced as part of a repair, use a new valve for

calculation.
Fig. 225: Measuring Distance Between Valve Stem End (Upper Edge) And Top Surface Of Cylinder
Head Using Depth Gauge
Courtesy of VOLKSWAGEN UNITED STATES, INC.
Measure distance - a - between valve stem end (upper edge) and top surface of cylinder head using a

depth gauge.
Calculate max. permissible refacing dimension from measured distance and minimum dimension.

2005 Audi A4 Quattro
Minimum dimension
2:34:44 AM Page 58