Audi Workshop Service and Repair Manuals

Special tools and workshop equipment required

• ◆ Feeler gauge
• ◆ Wood or plastic wedge

Notes:

• ◆ Hydraulic tappets cannot be adjusted or repaired.
• ◆ Irregular valve noise during starting is normal.

Test sequence

• ‒ Start engine and leave it running until coolant temperature has reached approx. 80 °C.
• ‒ Increase engine speed to about 2500 rpm for 2 minutes (perform road test if necessary).

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

• ‒ Remove cylinder head cover .

• ‒ Rotate crankshaft until the cams of the bucket tappets to be checked are pointing upwards:
• ‒ Vehicles with manual gearbox: Push vehicle forwards with 4th gear engaged and ignition switched off.
• ‒ Vehicles with automatic gearbox: Remove centre and right noise insulation as well as lower air duct pipe.
• ‒ Turn crankshaft clockwise at crankshaft toothed belt sprocket central bolt.
• ‒ Determine play between cam and tappet.

• ‒ → Use a wooden or plastic wedge to push down bucket tappet. If an 0.20 mm feeler gauge can be inserted between camshaft and tappet, renew tappet.
• ‒ Replacing bucket tappet => Removing camshaft, Page 15-53.

Notes:

• ◆ After installing the camshaft, wait for about 30 minutes before starting the engine. Hydraulic valve compensation elements have to settle (otherwise valves will strike pistons).
• ◆ 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.