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Valve dimensions > < Renewing valve stem oil seals with cylinder head removed

A4 Mk2

Checking hydraulic valve compensation elements
Checking hydraulic valve compensation elements
Special tools and workshop equipment required
t  Feeler gauge
  Note
t  Hydraulic valve compensation elements cannot be serviced.
t  Irregular valve noises when starting engine are normal.
Procedure
–  Start engine and run until coolant temperature reaches approx. 80 °C.
–  Increase engine speed to approx. 2500 rpm for 2 minutes (perform road test if necessary).
  Note
t  If irregular valve noise disappears but repeatedly re-occurs when travelling short distances, renew oil retention valves.
t  The oil retention valves are located below the oil filter bracket → Chapter.
If the hydraulic valve compensation elements are still noisy, locate the defective element as follows:
–  Remove cylinder head cover: left-side → Chapter, right-side → Chapter.
–  Rotate crankshaft until cam of hydraulic compensation element to be checked faces upwards. The procedure is:
t  Vehicles with manual gearbox: push vehicle forwards with 4th gear engaged and ignition switched off.
t  Vehicles with automatic gearbox: rotate crankshaft in clockwise direction via central bolt for vibration damper.
   
–  Determine play between cam and rocker finger.
–  Press rocker finger down -arrow- using a screwdriver.
If it is possible to insert a 0.20 mm feeler gauge between camshaft and rocker finger:
–  Renew hydraulic compensation element → Chapter „Removing and installing camshafts“.
  Note
t  After installing camshafts, wait for approx. 30 minutes before starting engine. Hydraulic valve compensation elements have to settle (otherwise valves will strike pistons).
t  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.
  A15-1011

Valve dimensions > < Renewing valve stem oil seals with cylinder head removed