Hydraulic valve lifters, checking

WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Special tools and equipment

Feeler gauge
Wooden or plastic wedge

NOTE:

Hydraulic valve lifters cannot be serviced.
Irregular valve noise when starting engine is normal.

Work sequence

Start engine and let run until coolant temperature reaches at least 80°C.
Increase RPM to 2500 for approx. 2 minutes, if necessary road test vehicle.

NOTE: If unusual valve noises disappear but then reappear during drive, replace oil retaining valve. Oil retaining valve, component location: Below cover at intake manifold. Refer to Oil check valves and spray jet valve, overview .

If hydraulic valve lifters are still loud, locate faulty valve lifter as follows:

Remove cylinder head cover. Refer to Left cylinder head cover, removing and installing or Right cylinder head cover, removing and installing .

Fig 1: Identifying Exhaust Pipe Fasteners

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For vehicles with auxiliary heater, remove bolts (arrows) for exhaust pipe of auxiliary heater on sound insulation.

Fig 2: Identifying Quick-Release Fasteners And Noise Insulation

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Remove bolts or quick-release screws -1- and -2- and remove front sound insulation.

Fig 3: Turning Engine Until Cams At Intake And Exhaust Camshaft Of Cylinder 3 (Right Cylinder Bank) Point Upward Uniformly

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Turn crankshaft at center bolt of toothed belt gear clockwise until cams of cylinder to be checked point upward (arrows).
Determine play between cams and valve lifters.

Fig 4: Pressing Valve Lifter Downward Using Wedge

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Press valve lifter downward using wooden or plastic wedge. If 0.20 mm feeler gauge can be inserted between camshaft and valve lifter, replace valve lifter. Valve lifters, replacing. Refer to Camshafts and camshaft adjusters, removing and installing .

NOTE:

After installing camshaft, do not start engine for at least 30 minutes. The hydraulic valve lifters have to settle (otherwise valves will strike the pistons).
After working on the valvetrain, carefully rotate engine by hand at least 2 full revolutions to ensure that valves do not strike the pistons when starting.