GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Astro - 4WD 🢒 Engine 🢒 Engine Electrical 🢒 Exhaust Manifold Replacement - Left Side

Removal Procedure

    Object Number: 246797 Size: SH
  1. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim.
  2. Disconnect the engine coolant temperature (ECT) sensor.

    3. Object Number: 321606 Size: SH
  3. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  4. Remove the left front tire. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
  5. Remove the left fender wheelhouse extension.
  6. Remove the catalytic converter assembly. Refer to Catalytic Converter Replacement .

    7. Object Number: 317450 Size: SH
  7. Remove the spark plug wires from the spark plugs. Refer to Spark Plug Wire Replacement in Engine Controls-4.3 L.
  8. Remove the spark plug wire support bolts.
  9. Remove the spark plug wire support with the spark plug wires.

    10. Object Number: 173197 Size: SH
  10. Remove the front 4 exhaust manifold bolts through the wheelhouse.
  11. Remove the 2 rear exhaust manifold bolts through the engine cover opening.
  12. Remove the exhaust manifold, gaskets and the spark plug wire shields from underneath the vehicle.
  13. Clean all gasket surfaces. Refer to Exhaust Manifold Cleaning and Inspection in Engine Unit Repair.

Installation Procedure

    Object Number: 476818 Size: SH

    Important: To assist in installing the exhaust manifold to the engine, the tabs on a NEW exhaust manifold gasket will hold the gasket and the bolts in place.

  1. Sub-assemble the NEW gaskets, the spark plug wire shields, and the bolts to the exhaust manifold.
  2. Ensure that the exhaust manifold bolts are held in place by the tabs on the exhaust manifold gaskets.
  3. Install the exhaust manifold. Refer to Exhaust Manifold Installation - Left Side in Engine Unit Repair.
    4. • Tighten the 2 rear exhaust manifold bolts through the engine cover opening.
    • Tighten the front 4 exhaust manifold bolts through the wheelhouse.

    Object Number: 317450 Size: SH
  4. Install the spark plug wires to the spark plugs. Refer to Spark Plug Wire Replacement in Engine Controls-4.3 L.

    5. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  5. Install the spark plug wire support and bolts.

    6. Tighten
    Tighten the spark plug wire support bolts to 12 N·m (106 lb in).

  6. Install the catalytic converter assembly. Refer to Catalytic Converter Replacement .

    7. Object Number: 321606 Size: SH
  7. Install the fender wheelhouse extension.
  8. Install the left front tire. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
  9. Lower the vehicle.

    10. Object Number: 246797 Size: SH
  10. Connect the ECT sensor electrical connector.
  11. Install the engine cover. Refer to Engine Cover Replacement in Interior Trim.