Town Car V8-4.6L VIN W (1997)
Valve Guide: Testing and Inspection
Valve Stem to Guide Clearance
DESCRIPTION
Check the valve stem-to-valve guide clearance of each valve in its respective valve guide with Valve Stem Clearance Tool TOOL-6505-E and Dial
Indicator with Bracketry TOOL-4201-C or equivalent. Use a flat-end indicator point.
PROCEDURES
1. Install the tool on the valve stem until the lip is fully seated, and tighten the knurled set screw firmly.
2. Permit the valve to drop away from its seat until the tool contacts the upper surface of the valve guide.
3. Position and zero the dial indicator on the cylinder head.
4. Move the valve back and forth 90° from the dial indicator shaft.
5. Divide the measurement by two to determine the actual guide clearance.
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The intake clearance is 0.020-0.069 mm (0.000787-0.002717 inch).
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The exhaust clearance is 0.046-0.095 mm (0.001811-0.003740 inch).
6. If the clearance exceeds specification, inspect the valve stem.
7, If the valve stem is within specification, ream the valve guide for the next oversize valve stem.
