S5 Quattro Coupe V8-4.2L (CAUA) (2009)
Valve Guide: Testing and Inspection
Valve Guides, Checking
Special tools, testers and auxiliary items required
‹› Dial Gauge Holder (VW 387)
‹› Dial Gauge (VAS 6079)
Procedure
‹› If valve is replaced during repair, use new valve for measurement.
‹› Due to different stem diameters, only use an intake valve in the intake guide and an exhaust valve in the exhaust guide.
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Place valve in valve guide.
‹› Valve stem tip must seal with valve guide.
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Determine tip clearance.
‹› Wear limit: 0.8 mm.
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If wear limit is exceeded, re-measure using new valves.
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If wear limit is still exceeded, replace cylinder head.
‹› The valve guides cannot be replaced.