audi Workshop Repair Guides

Audi Workshop Service and Repair Manuals

Renewing valve stem seals > < Removing and installing camshaft
4-cylinder Diesel Direct Injection Engine (TDI), Mechanics
Servicing valve gear
Checking hydraulic bucket tappets

Special tools, testers and auxiliary equipment required

  • ◆ Feeler gauge
  • ◆ Wood or plastic wedge

Notes:

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

Note:

If the irregular valve noises stop but recur repeatedly during short journeys, a new oil retention valve must be fitted. Oil retention valve location: In the oil filter bracket .

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

  • ‒ Remove cylinder head cover => Page 15-8.
  • ‒ Rotate crankshaft until the cams of the 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 noise insulation and turn crankshaft clockwise by applying spanner to central bolt on crankshaft sprocket.
  • ‒ Determine play between cam and tappet.
 
V15-0708
  • ‒ → Press down tappet with a wooden or plastic wedge. If an 0.20 mm feeler gauge can be inserted between camshaft and tappet, renew tappet.
  • ‒ Replacing bucket tappet => Removing camshaft, Page 15-44.

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.

Renewing valve stem seals > < Removing and installing camshaft