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Valve dimensions > < Renewing valve stem oil seals

A4 Mk2

Checking supporting elements with hydraulic clearance compensation
Checking supporting elements with hydraulic clearance compensation
Special tools and workshop equipment required
t  Feeler gauge
  Note
t  It is not possible to service the supporting elements with hydraulic clearance compensation.
t  Irregular valve noises when starting engine are normal.
Test sequence
–  Start engine and let it run until the radiator fan has switched on once.
–  Increase engine speed to approx. 2500 rpm for 2 minutes (perform road test if necessary).
  Note
If the irregular valve noises stop but recur repeatedly during short trips, renew the oil filter bracket with oil retention valve → Item.
If the supporting elements with hydraulic clearance compensation are still noisy, proceed as follows to determine defective supporting element:
–  Remove cylinder head cover → Chapter.
–  Turn crankshaft until cams of supporting element to be tested are at top:
t  Vehicles with manual gearbox: push vehicle forwards with 4th gear engaged and ignition switched off.
t  Vehicles with multitronic gearbox: remove noise insulation and rotate crankshaft in clockwise direction via crankshaft sprocket central bolt.
   
–  Determine clearance between cam and roller rocker finger.
–  Press roller rocker finger down using a screwdriver -arrow-.
If it is possible to insert a feeler gauge of 0.20 mm between camshaft and roller rocker finger:
–  Renew supporting 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.
  A15-0926

Valve dimensions > < Renewing valve stem oil seals