Hydraulic lifters, checking

NOTE:

Replace defective valve lifter complete (cannot be adjusted or repaired).
Irregular valve noises when starting engine are normal.

Start engine and run until the radiator fan has switched on once.
Increase engine speed to about 2500 RPM for 2 minutes (perform road test if necessary).

NOTE: If the irregular valve noises stop but recur repeatedly during short journeys, a new oil retention valve must be installed. The oil retention valve is located in the oil filter bracket. Refer to Part II .

If the hydraulic valve lifters are still noisy, locate defective valve lifters as follows:

Remove cylinder head cover. Refer to Cylinder head, removing and installing .
Rotate crankshaft clockwise by turning the central securing bolt on the crankshaft toothed belt sprocket until the cams of the valve lifter to be checked are pointing upward.
Determine play between cam and hydraulic lifter.

Fig 1: Pressing Valve Lifter Down With Wooden Or Plastic Wedge

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Press valve lifter down with a wooden or plastic wedge. If an 0.20 mm feeler gauge can be inserted between camshaft and valve lifter, replace valve lifter.
Replacing valve lifter. Refer to Camshafts and hydraulic chain tensioner, removing and installing , Removing and installing camshafts and hydraulic chain tensioner

NOTE:

After installing new valve lifters the engine must not be started for approx. 30 minutes (otherwise valves will strike pistons). Rotate crankshaft two times before starting engine.
After working on the valve gear, turn the engine carefully at least 2 rotations to ensure that none of the valves make contact when the starter is operated.