A6 Quattro Sedan V6-2.7L Turbo (APB) (2000)
Lifter / Lash Adjuster: Testing and Inspection
Hydraulic bucket lifters, checking
Note:
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Replace malfunctioning lifters (lifters cannot be adjusted or repaired).
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When new lifters have been installed the engine must not be started for about 30 minutes (otherwise valves will strike pistons).
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Irregular valve noises when starting engine are normal.
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Start engine and run until coolant temperature reaches approximately 80°C.
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Increase engine speed to about 2500 RPM for approximately 2 minutes: if necessary, perform road test.
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If the hydraulic lifters are still noisy, locate malfunctioning lifters as follows:
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Remove cylinder head cover.
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Rotate crankshaft clockwise by turning securing bolt for toothed belt sprocket until cams of lifters to be checked are pointing upward.
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Measure clearance between cam and lifter.
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Push lifter down with a wooden or plastic wedge. If a 0.20 mm feeler gauge can then be inserted between camshaft and lifter, replace lifter if
necessary: See: Camshaft/Service and Repair
Note: If irregular valve noise occurs repeatedly during short journeys and disappears after extended driving, the oil check valves must be
renewed.