Valve Seat Width Measurement Procedure

WARNING: This page is about a different car, the 2002 Oldsmobile Aurora and 2001 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.

Measure the valve seat width in the cylinder head using a proper scale.

Fig 1: Measuring Valve Seat Width
Courtesy of GENERAL MOTORS CORP.
Measure the seat width on the valve face (1) using a proper scale.
Important: The seat contact area must be at least 0.5 mm (0.020 in) from the outer diameter, margin, of the valve. If the contact area is too close to the margins, the seat must be reconditioned to move the contact area away from the margin.

Fig 2: Measuring Seat Width On Valve Face

Courtesy of GENERAL MOTORS CORP.

Compare your measurements with the specifications listed in Engine Mechanical Specifications .
If the seat widths are acceptable, check the valve seat roundness using the Valve Seat Roundness Measurement Procedure.
If the seat width is not acceptable, you must grind the valve seat using the Valve and Seat Reconditioning Procedure to bring the width back into specification. Proper valve seat width is critical to providing the correct amount of valve heat dissipation.