GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2009 🢒 Impala 🢒 Engine 🢒 Engine Cooling 🢒 Exhaust Manifold Replacement - Left Side

Exhaust Manifold Replacement - Left Side 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
  6. Remove the exhaust manifold heat shield bolts (604).
  7. Remove the exhaust manifold heat shield (603).
  8. Remove the heater hose retainer bolts in order to be able to remove the manifold.

    9. Object Number: 1411880 Size: SH
  9. Remove the exhaust manifold bolts.
  10. Remove the exhaust manifold.
  11. Remove and discard the exhaust manifold gasket.

Installation Procedure

Note: 

   • 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. Caution: Refer to Fastener Caution in the Preface section.

  2. Install a NEW exhaust manifold gasket, the exhaust manifold and bolts.

    3. 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.
  3. Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the rear of the left cylinder head.

    4. Object Number: 1411884 Size: SH
  4. Install the exhaust manifold heat shield (603).
  5. Install the exhaust manifold heat shield bolts (604).

    6. Tighten
    Tighten the bolts to 9 N·m (80 lb in).

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

    8. Object Number: 1554543 Size: SH
  8. Install the exhaust crossover pipe nuts from the left exhaust manifold.

    9. Tighten
    Tighten the nuts to 25 N·m (18 lb ft).

  9. Install the exhaust crossover pipe heat shield.
  10. Install the heater pipe retainer bolts.

    11. Tighten
    Tighten the bolts to 16 N·m (12 lb ft).

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

Exhaust Manifold Replacement - Left Side RPOs LZE/LZ4/LZ8

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
  4. Remove the exhaust crossover pipe heat shield bolts.
  5. Remove the exhaust crossover pipe heat shield.

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

    7. Object Number: 1617970 Size: SH
  7. Remove the exhaust manifold bolts.
  8. Remove the exhaust manifold bolts.
  9. Remove the exhaust manifold.
  10. 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. Caution: Refer to Fastener Caution in the Preface section.

  3. Install the exhaust manifold bolts.

    4. Tighten
    Tighten the bolts to 20 N·m (15 lb ft).


    Object Number: 1617975 Size: SH
  4. Install the exhaust crossover pipe to left exhaust manifold nuts.

    5. Tighten
    Tighten the nuts to 20 N·m (15 lb ft).


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

    7. Tighten
    Tighten the bolts to 10 N·m (89 lb in).


    Object Number: 1617968 Size: SH
  7. Install the exhaust manifold heat shield.
  8. Install the exhaust manifold heat shield bolts.

    9. Tighten
    Tighten the bolts to 10 N·m (89 lb in).

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