GM Service Manual Online
For 1990-2009 cars only

    Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1401959  Size: SH

    Important: 

       • Tighten the exhaust manifold bolts as specified in the service procedure. Improperly installed and/or leaking exhaust manifold gaskets may affect vehicle emissions and/or on-board diagnostic (OBD) II system performance.
       • The cylinder head exhaust manifold bolt hole threads must be clean and free of debris or threadlocking material.
       • Do not apply sealant to the first 3 threads of the bolt.

  1. Install the heat shield (603) and bolts (604).
  2. Tighten
    Tighten the heat shield bolts to 9 N·m (80 lb in).

  3. Install the exhaust pipe studs (605).
  4. Tighten
    Tighten the studs to 20 N·m (15 lb ft).


    Object Number: 1401957  Size: SH
  5. Apply a 5 mm (0.2 in) wide band of threadlock GM P/N 12345493 (Canadian P/N 10953488), or equivalent, to the threads of the exhaust manifold bolts. Refer to Adhesives, Fluids, Lubricants, and Sealers.
  6. Install the exhaust manifold, NEW gasket, and bolts.
  7. Tighten

    1. Tighten the exhaust manifold bolts a first pass to 15 N·m (11 lb ft). Tighten the exhaust manifold bolts beginning with the center 2 bolts. Alternate from side-to-side, and work toward the outside bolts.
    2. Tighten the exhaust manifold bolts a final pass to 20 N·m (15 lb ft). Tighten the exhaust manifold bolts beginning with the center 2 bolts. Alternate from side-to-side, and work toward the outside bolts.
  8. Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the rear of the left cylinder head.