RS 4 Quattro Cabriolet V8-4.2L (BNS) (2008)
Lifter / Lash Adjuster: Testing and Inspection
Hydraulic Adjusting Elements, Checking
‹› The hydraulic adjusting elements cannot be repaired.
‹› Irregular valve noises are normal while starting the engine.
Special tools, testers and auxiliary items required
‹› Feeler gauge
Procedure
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Start engine and allow it to run until coolant fan has switched on once.
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Increase engine speed for about 2 minutes to approximately 2500 RPM, perform road test if necessary.
‹› If irregular valve noises disappear but reappear during short drives, oil check valve should be replaced. Oil check valve location. Refer to => [ Oil
Check Valve and Spray Nozzle Valve Assembly Overview ] See: Engine Lubrication/Oil Pump/Oil Pressure Regulator Valve/Service and
Repair/Oil Check Valve and Spray Nozzle Valve Assembly Overview.
If the hydraulic adjusting elements are still loud, determine which element is faulty:
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Remove the cylinder head cover. Refer to: Left => [ Left Cylinder Head Cover ] See: Cylinder Head Assembly/Valve Cover/Service and
Repair/Left Cylinder Head Cover, right => [ Right Cylinder Head Cover ] See: Cylinder Head Assembly/Valve Cover/Service and Repair/Right
Cylinder Head Cover.
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Rotate crankshaft until cam lobes on support element that will be checked face upward. To do this, move vehicle forward with 4th gear engaged
and ignition switched off.
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Check play between cam lobes and roller rocker lever.
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Press roller rocker lever down with screwdriver - arrow -.
If it is possible to insert a 0.20 mm feeler gauge between the camshaft the roller rocker lever:
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Replace the adjusting element. Refer to => [ Camshafts ] See: Camshaft/Service and Repair.