Lincoln Aviator: Engine System - General Information / General Procedures - Valve Guide Inner Diameter

Check

NOTE: Refer to the appropriate Section 303-01 for the specification.

1. NOTE: Valve guides tend to wear in an hourglass pattern. The ball gauge can be inserted into the combustion chamber side of the valve guide, if necessary.

   • Use a ball gauge to determine the inside diameter of the valve guides in 2 directions at the top, middle and bottom of the valve guide.
     
   • Measure the ball gauge with a micrometer.
     
   • If the valve guide is not within specifications, install a new cylinder head assembly.