Valve Seat Audi A6 C5

Note. When repairing engines with leaking valves, it is not sufficient to replace or renew valve seats and valves. It is also necessary to check the valve guides for wear. This is particularly important on high mileage engines. The valve seats should only be refaced just enough to produce a perfect seating pattern. The maximum permissible refacing dimension must be calculated before beginning refacing. If the refacing dimension is exceeded, the function of the hydraulic valve lifters can no longer be guaranteed and the cylinder head should be replaced. If the valve is to be replaced as part of a repair, use a new valve for the calculation.

1. Insert valve into guide. Press valve tightly against valve seat. Lay a straightedge across top of cylinder head. Measure distance between valve stem tip and bottom of straightedge. This is valve installed height. If a new valve is going to be installed, use new valve to make this measurement.
2. If valve stem height is less than 1.339" (34.0 mm) on intake valve (outer), 1.327" (33.7 mm) intake valve (center), or 1.354" (34.4 mm) on exhaust valve, install a new valve and measure again. see scheme 95
3. If valve stem height measurement is still less than specification, replace cylinder head. If valve stem height exceeds specification, seat can be machined; however, DO NOT machine enough material away from seat to cause valve stem height to be less than minimum specification.

Scheme 82

Scheme 83

1. Remove camshafts. See «CAMSHAFTS»(ref-147486-S28562019622002091600000) under REMOVAL & INSTALLATION.
2. Remove valve lifters and place them with contact surface downward. During removal make sure lifters are not interchanged.
3. Remove spark plugs with spark plug removal tool (3122B).
4. Set piston of relevant cylinder to Bottom Dead Center (BDC).
5. Screw VW pressure hose (653/3) into spark plug thread. see scheme 96
6. Secure (3362) valve spring compressor to cylinder head with tool securing bolt and position installing tool for compressing valve springs to following positions. Outer intake valves: lower position, Center intake valve: upper position and Exhaust valve: lower position. see scheme 96
7. Connect pressure hose to compressed air system supplying at least 6 bar (87 psi) and remove valve springs.
8. Remove valve stem seals with puller (3364) for valve shaft seal. see scheme 97