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For 1990-2009 cars only

Exhaust Manifold Replacement - Left Side RPO LS4

Removal Procedure


    Object Number: 1554543  Size: SH
  1. Remove the engine sight shield. Refer to Upper Intake Manifold Sight Shield Replacement .
  2. Remove the exhaust crossover pipe heat shield in order to access the cross pipe to the exhaust manifold nuts.
  3. Remove the exhaust crossover pipe nuts from the left exhaust manifold.
  4. Remove the left side spark plugs. Refer to Spark Plug Replacement .
  5. Remove the oil level indicator tube. Refer to Oil Level Indicator and Tube Replacement .

  6. Object Number: 1411884  Size: SH
  7. Remove the exhaust manifold heat shield bolts (604).
  8. Remove the exhaust manifold heat shield (603).
  9. Remove the heater hose retainer bolts in order to be able to remove the manifold.

  10. Object Number: 1411880  Size: SH
  11. Remove the exhaust manifold bolts.
  12. Remove the exhaust manifold.
  13. Remove and discard the exhaust manifold gasket.
  14. Clean and inspect the left exhaust manifold. Refer to Exhaust Manifold Cleaning and Inspection .

Installation Procedure

Important: 

   • Tighten the exhaust manifold bolts as specified in the service procedure. Improperly installed and/or leaking exhaust manifold gaskets my 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 threadlock to the first three thread of the bolts.


    Object Number: 1411880  Size: SH
  1. 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.
  2. Notice: Refer to Fastener Notice in the Preface section.

  3. Install a NEW exhaust manifold gasket, the exhaust manifold and bolts.
  4. Tighten

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

  6. Object Number: 1411884  Size: SH
  7. Install the exhaust manifold heat shield (603).
  8. Install the exhaust manifold heat shield bolts (604).
  9. Tighten
    Tighten the bolts to 9 N·m (80 lb in).

  10. Install the oil level indicator tube. Refer to Oil Level Indicator and Tube Replacement .
  11. Install the left side spark plugs. Refer to Spark Plug Replacement .

  12. Object Number: 1554543  Size: SH
  13. Install the exhaust crossover pipe nuts from the left exhaust manifold.
  14. Tighten
    Tighten the nuts to 25 N·m (18 lb ft).

  15. Install the exhaust crossover pipe heat shield.
  16. Install the heater pipe retainer bolts.
  17. Tighten
    Tighten the bolts to 16 N·m (12 lb ft).

  18. Install the engine sight shield. Refer to Upper Intake Manifold Sight Shield Replacement .

Exhaust Manifold Replacement - Left Side RPOs LZE/LZ4/LZ9

Removal Procedure


    Object Number: 1617968  Size: SH
  1. Remove the engine mount strut bracket. Refer to Engine Mount Strut Bracket Replacement - Left Side .
  2. Remove the exhaust manifold heat shield bolts.
  3. Remove the exhaust manifold heat shield.

  4. Object Number: 1617973  Size: SH
  5. Remove the exhaust crossover pipe heat shield bolts.
  6. Remove the exhaust crossover pipe heat shield.

  7. Object Number: 1617975  Size: SH
  8. Remove the exhaust crossover pipe to left exhaust manifold nuts.

  9. Object Number: 1617970  Size: SH
  10. Remove the exhaust manifold bolts.
  11. Remove the exhaust manifold bolts.
  12. Remove the exhaust manifold.
  13. Remove and discard the exhaust manifold gasket.

Installation Procedure


    Object Number: 1617970  Size: SH
  1. Install a NEW exhaust manifold gasket onto the cylinder head studs.
  2. Install the exhaust manifold.
  3. Notice: Refer to Fastener Notice in the Preface section.

  4. Install the exhaust manifold bolts.
  5. Tighten
    Tighten the bolts to 20 N·m (15 lb ft).


    Object Number: 1617975  Size: SH
  6. Install the exhaust crossover pipe to left exhaust manifold nuts.
  7. Tighten
    Tighten the nuts to 20 N·m (15 lb ft).


    Object Number: 1617973  Size: SH
  8. Install the exhaust crossover pipe heat shield.
  9. Install the exhaust crossover pipe heat shield bolts.
  10. Tighten
    Tighten the bolts to 10 N·m (89 lb in).


    Object Number: 1617968  Size: SH
  11. Install the exhaust manifold heat shield.
  12. Install the exhaust manifold heat shield bolts.
  13. Tighten
    Tighten the bolts to 10 N·m (89 lb in).

  14. Install the engine mount strut bracket. Refer to Engine Mount Strut Bracket Replacement - Left Side .