GM Service Manual Online
For 1990-2009 cars only

Exhaust Manifold Removal Left


    Object Number: 233866  Size: SH

    Important: It is difficult to mount the engine on an engine stand with the exhaust manifold/crossover pipe in place. When the engine is out of the vehicle, properly support the engine on the floor or bench and remove the exhaust manifold before mounting the engine on an engine stand.

  1. Remove the oil level indicator tube bolt.
  2. Remove the oil level indicator and tube by sliding the tube up through the exhaust manifold.
  3. Remove and discard the O-ring from the oil level indicator tube.

  4. Object Number: 277022  Size: SH
  5. Remove the exhaust manifold heat shield bolts.
  6. Remove the exhaust manifold heat shield.

  7. Object Number: 240838  Size: SH
  8. Loosen the exhaust manifold bolts.

  9. Object Number: 234125  Size: SH
  10. Remove the left exhaust manifold to crossover pipe flange bolts.
  11. Remove the left exhaust manifold bolts.
  12. Important: DO NOT reuse the exhaust manifold gasket or flange gasket.

  13. Remove the left exhaust manifold, exhaust manifold gasket and flange gasket.

  14. Object Number: 281929  Size: SH
  15. Remove the left engine coolant heater bolt.
  16. Remove the left engine coolant heater.

Exhaust Manifold Removal Right


    Object Number: 234135  Size: SH

    Important: It is difficult to mount the engine on an engine stand with the exhaust manifold/crossover pipe in place. When the engine is out of the vehicle, properly support the engine on the floor or bench and remove the exhaust manifold before mounting the engine on an engine stand.

    Important: The EGR valve inlet pipe incorporates a crush seal connection at the water crossover. The EGR valve inlet pipe must be replaced if disconnected from the water crossover.

  1. Disconnect the EGR valve inlet pipe from the exhaust crossover pipe (3).
  2. Remove the EGR valve inlet pipe to water crossover bolt (2).
  3. Remove the EGR valve inlet pipe (1) and discard.

  4. Object Number: 235262  Size: SH
  5. Remove the oxygen sensor (1) from the manifold.
  6. Inspect the oxygen sensor for excessive deposits or damage. Replace the oxygen sensor if necessary.

  7. Object Number: 234122  Size: SH
  8. Remove the right exhaust manifold bolts.
  9. Important: DO NOT reuse the exhaust manifold gasket.

  10. Remove the right exhaust manifold and exhaust manifold gasket.

  11. Object Number: 483110  Size: SH
  12. Disconnect the engine wiring harness from the knock sensor.
  13. Remove the engine wiring harness from the wiring harness bracket (1).

  14. Object Number: 483108  Size: SH
  15. Remove the engine wiring harness from the lower crankcase.

  16. Object Number: 483099  Size: SH
  17. Disconnect the engine wiring harness from the ECT sensor.
  18. Remove the engine wiring harness.

  19. Object Number: 235257  Size: SH
  20. Remove the ECT sensor.

  21. Object Number: 483127  Size: SH
  22. Remove the oil pressure switch.

  23. Object Number: 483083  Size: SH
  24. Remove the wiring harness bracket bolt.
  25. Remove the wiring harness bracket.

  26. Object Number: 483079  Size: SH
  27. Remove the knock sensor.

  28. Object Number: 281918  Size: SH
  29. Remove the right engine coolant heater bolt.
  30. Remove the right engine coolant heater.

Exhaust Manifold Removal Left with RPO NC1


    Object Number: 520843  Size: SH

    Important: It is difficult to mount the engine on an engine stand with the exhaust manifold/crossover pipe in place. When the engine is out of the vehicle, properly support the engine on the floor or bench and remove the exhaust manifold before mounting the engine on an engine stand.

  1. Remove the oil level indicator tube bolt.
  2. Remove the oil level indicator and tube by sliding the tube up through the exhaust manifold.
  3. Remove and discard the O-ring from the oil level indicator tube.

  4. Object Number: 483149  Size: SH
  5. Remove the A.I.R. vacuum hose to the retaining clip on the engine lift bracket.

  6. Object Number: 483143  Size: SH
  7. Disconnect the A.I.R. vacuum hose from the throttle body (1).
  8. Disconnect the vacuum tube from the A.I.R. control valve.

  9. Object Number: 520825  Size: SH
  10. Remove the left A.I.R. control valve pipe bolt and nut to the left A.I.R. manifold.
  11. Remove the left A.I.R. control valve bolts from the torque strut bracket.

  12. Object Number: 520847  Size: SH
  13. Remove the left A.I.R. manifold bolts.
  14. Remove the left A.I.R. manifold.

  15. Object Number: 277022  Size: SH
  16. Remove the exhaust manifold heat shield bolts.
  17. Remove the exhaust manifold heat shield.

  18. Object Number: 240838  Size: SH
  19. Loosen the exhaust manifold bolts.

  20. Object Number: 234125  Size: SH
  21. Remove the left exhaust manifold to crossover pipe flange bolts.
  22. Remove the left exhaust manifold bolts.
  23. Important: DO NOT reuse the exhaust manifold gasket or flange gasket.

  24. Remove the left exhaust manifold.
  25. Remove the left exhaust manifold gasket and flange gasket.

  26. Object Number: 281929  Size: SH
  27. Remove the left engine coolant heater bolt.
  28. Remove the left engine coolant heater.

Exhaust Manifold Removal Right with RPO NC1


    Object Number: 576168  Size: SH

    Important: It is difficult to mount the engine on an engine stand with the exhaust manifold/crossover pipe in place. When the engine is out of the vehicle, properly support the engine on the floor or bench and remove the exhaust manifold before mounting the engine on an engine stand.

  1. Disconnect the vacuum tube (1) from the right A.I.R. control valve.
  2. Disconnect the vacuum tubes (2) from the vacuum solenoid.
  3. Remove the vacuum tube harness.

  4. Object Number: 520833  Size: SH
  5. Remove the right A.I.R. control valve pipe bolt and nut from the right A.I.R. manifold.

  6. Object Number: 520828  Size: SH
  7. Remove the right A.I.R. control valve bolts.
  8. Remove the right A.I.R. control valve.

  9. Object Number: 520844  Size: SH
  10. Remove the right A.I.R. manifold bolts.
  11. Remove the right A.I.R. manifold.

  12. Object Number: 234135  Size: SH

    Important: The EGR valve inlet pipe incorporates a crush seal connection at the water crossover. The EGR valve inlet pipe must be replaced if disconnected from the water crossover.

  13. Disconnect the EGR valve inlet pipe from the exhaust crossover pipe (3).
  14. Remove the EGR valve inlet pipe to water crossover bolt (2).
  15. Remove the EGR valve inlet pipe (1).

  16. Object Number: 235262  Size: SH
  17. Remove the oxygen sensor (1) from the manifold. Inspect the oxygen sensor for excessive deposits or damage. Replace the oxygen sensor if necessary.

  18. Object Number: 234122  Size: SH
  19. Remove the right exhaust manifold bolts.
  20. Important: DO NOT reuse the exhaust manifold gasket.

  21. Remove the right exhaust manifold and exhaust manifold gasket.

  22. Object Number: 483110  Size: SH
  23. Disconnect the engine wiring harness from the knock sensor.
  24. Remove the engine wiring harness from the wiring harness bracket (1).

  25. Object Number: 483108  Size: SH
  26. Remove the engine wiring harness from the lower crankcase.

  27. Object Number: 483099  Size: SH
  28. Disconnect the engine wiring harness from the ECT sensor.
  29. Remove the engine wiring harness.

  30. Object Number: 235257  Size: SH
  31. Remove the ECT sensor.

  32. Object Number: 483127  Size: SH
  33. Remove the oil pressure switch.

  34. Object Number: 483083  Size: SH
  35. Remove the wiring harness bracket bolt.
  36. Remove the wiring harness bracket.

  37. Object Number: 483079  Size: SH
  38. Remove the knock sensor.

  39. Object Number: 281918  Size: SH
  40. Remove the right engine coolant heater bolt.
  41. Remove the right engine coolant heater.