GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2008 🢒 G3 🢒 Engine 🢒 Engine Mechanical - 1.2L 🢒 Valve Stem and Valve Guide Clearance Inspection

    Object Number: 1240694 Size: SH
  1. Inspect the diameter of the valve stem using a micrometer to check the clearance between the valve stem and the valve guide.

    2. Specifications

    • The intake outer diameter is 5.465-5.480 mm (0.2152-0.2157 in).
    • The exhaust outer diameter is 5.440-5.455 mm (0.2142-0.2148 in).

    Object Number: 1240696 Size: SH
  2. Inspect the inner diameter of the valve guide using a bore gage (1), at least 1 place in the direction to the valve length.

    3. Specifications

    • The intake inner diameter is 5.500-5.512 mm (0.2165-0.2170 in).
    • The exhaust inner diameter is 5.500-5.512 mm (0.2165-0.2170 in).
  3. Inspect the clearance between the valve stem and the valve guide.

    4. Specifications

    • The intake clearance is 0.020-0.047 mm (0.0008-0.0019 in).
    • The exhaust clearance is 0.0045-0.072 mm (0.0018-0.0028 in).

    Object Number: 1240699 Size: SH
  4. If a bore gage is not available, measure the clearance using a dial gage by moving the edge of the stem to the directions of (1, 2, 3).
    5. • The intake clearance is 0.14 mm (0.0055 in).
    • The exhaust clearance is 0.18 mm (0.0071 in).
  5. If the measured value is over the limit, replace the valve stem or valve guide.