GM Celebrity/Century/Ciera/6000 1982-1996 Repair Guide

Exhaust Manifold

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REMOVAL & INSTALLATION



2.2L Engine

See Figure 1

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air cleaner and air inlet duct.
  4.  
  5. Remover the lower air inlet duct.
  6.  
  7. Remove the engine drive belt, then remove the alternator.
  8.  
  9. Unsecure the engine torque strut bracket from the cylinder head.
  10.  
  11. Loosen and remove the alternator bracket.
  12.  
  13. Raise and support the vehicle safely.
  14.  
  15. Remove the two bolts securing the exhaust pipe to the exhaust manifold.
  16.  
  17. Lower the vehicle.
  18.  
  19. Remove the dipstick tube mounting bolt, then the dipstick tube and stick.
  20.  
  21. Disconnect the electrical harness to the Oxygen sensor (O 2 ) sensor.
  22.  
  23. Unsecure the manifold mounting bolts/nuts, then remove the manifold.
  24.  



Click image to see an enlarged view

Fig. Fig. 1: Exhaust manifold assembly used on 2.2L engines

To install:
  1. Clean all the gasket surfaces completely.
  2.  
  3. Install the exhaust manifold, then tighten the mounting bolts to 116 inch lbs. (13 Nm).
  4.  
  5. Connect the O 2 sensor harness to the sensor.
  6.  
  7. Attach the dipstick tube with it's mounting bolt.
  8.  
  9. Raise and support the vehicle.
  10.  
  11. Connect the front exhaust pipe to the exhaust manifold, then tighten the mounting bolts to 18 ft. lbs. (25 Nm).
  12.  
  13. Lower the vehicle.
  14.  
  15. Install the alternator rear support bracket, then tighten the three mounting bolts to 74 ft. lbs. (100 Nm).
  16.  
  17. Install the engine torque strut bracket to the engine, then tighten the nuts to 41 ft. lbs. (56 Nm) and the bolt to 40 ft. lbs. (55 Nm).
  18.  
  19. Attach the torque strut, then tighten the bolts to 40 ft. lbs. (55 Nm).
  20.  
  21. Attach the alternator to the engine.
  22.  
  23. Install the drive belt.
  24.  
  25. Attach the lower air intake duct, then the air intake resonator to the upper tie bar.
  26.  
  27. Install the air cleaner and duct work.
  28.  
  29. Connect the negative battery cable.
  30.  
  31. Start the vehicle, then check for leaks.
  32.  

2.5L Engine
  1. Disconnect the negative battery cable. Remove the air cleaner and the preheat tube.
  2.  
  3. Remove the manifold strut bolts from the radiator support panel and the cylinder head.
  4.  
  5. Remove the air conditioning compressor bracket to one side. Do not disconnect any of the refrigerant lines.
  6.  
  7. If necessary, remove the dipstick tube attaching bolt and the engine mount bracket from the cylinder head.
  8.  
  9. Raise the vehicle and support safely. Disconnect the exhaust pipe from the manifold.
  10.  
  11. Remove the manifold attaching bolts, then remove the manifold and gasket.
  12.  

To install:
  1. Clean all the gasket surfaces completely.
  2.  
  3. Install the exhaust manifold and gasket to the cylinder head. Tighten all bolts in sequence to the specified value. The outside bolts to 28 ft. lbs. (38 Nm), and the inside bolts to 37 ft. lbs. (50 Nm).
  4.  
  5. Connect the exhaust pipe to the manifold. Lower the vehicle.
  6.  
  7. Install the dipstick tube attaching bolt and the engine mount bracket to the cylinder head.
  8.  
  9. Install the air conditioning compressor bracket.
  10.  
  11. Install the manifold strut bolts to the radiator support panel and the cylinder head.
  12.  
  13. Install the air cleaner and the preheat tube.
  14.  
  15. Connect the negative battery cable.
  16.  

2.8L Engine

See Figures 2 and 3

LEFT SIDE
  1. Remove the air cleaner. Remove the exhaust crossover pipe.
  2.  
  3. Remove the air supply plumbing from the exhaust manifold, if equipped.
  4.  
  5. Raise and support the car. Unbolt and remove the exhaust pipe at the manifold.
  6.  
  7. Unbolt and remove the manifold and gasket.
  8.  

To install:
  1. Clean the mating surfaces of the cylinder head and manifold. Install the manifold and gasket to the head, then install the retaining bolts finger-tight.
  2.  
  3. Tighten the manifold bolts in a circular pattern, working from the center to the ends, to 25 ft. lbs. (34 Nm) in two stages.
  4.  
  5. Connect the exhaust pipe to the manifold.
  6.  
  7. The remainder of installation is the reverse of removal.
  8.  



Click image to see an enlarged view

Fig. Fig. 2: If necessary, disconnect the crossover pipe from the exhaust manifold



Click image to see an enlarged view

Fig. Fig. 3: Once the retaining bolts are removed, the exhaust manifold can be removed from the engine

RIGHT SIDE
  1. Disconnect the negative battery cable.
  2.  
  3. Raise and safely support the vehicle.
  4.  
  5. Disconnect the exhaust pipe and lower the vehicle.
  6.  
  7. Remove the air cleaner assembly, breather, mass air flow sensor and heat shield.
  8.  
  9. Remove the crossover at the manifold.
  10.  
  11. Remove the accelerator and TV cables and brackets, as required.
  12.  
  13. Remove the exhaust manifold retaining bolts, then remove the manifold and gasket.
  14.  

To install:
  1. Clean all the gasket surfaces completely.
  2.  
  3. Install the exhaust manifold and gasket with the retaining bolts. Tighten to 15-22 ft. lbs. (20-30 Nm).
  4.  
  5. If removed, install the accelerator, TV cables and brackets.
  6.  
  7. Install the crossover at the manifold.
  8.  
  9. Install the air cleaner assembly, breather, mass air flow sensor and heat shield.
  10.  
  11. Raise and safely support the vehicle.
  12.  
  13. Connect the exhaust pipe and lower the vehicle.
  14.  
  15. Connect the negative battery cable.
  16.  

3.0L Engine
LEFT SIDE
  1. Disconnect the battery ground.
  2.  
  3. Unbolt and remove the crossover pipe.
  4.  
  5. Remove the upper engine support strut.
  6.  
  7. Unbolt and remove the manifold and gasket.
  8.  

To install:
  1. Clean all the gasket surfaces completely.
  2.  
  3. Install the exhaust manifold, making sure the new gasket is in place.
  4.  
  5. Tighten the mounting bolts for the manifold to 25 ft. lbs. (34 Nm).
  6.  
  7. Attach the upper engine support to the vehicle.
  8.  
  9. Install the engine crossover pipe.
  10.  
  11. Connect the negative battery cable.
  12.  

RIGHT SIDE
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the intermediate shaft pinch bolt and separate the intermediate shaft from the stub shaft.
  4.  


CAUTION
Failure to disconnect the intermediate shaft from the rack and pinion stub shaft can result in damage to the steering gear and/or the intermediate shaft. This damage can cause loss of steering control.

  1. Raise the support the vehicle on jackstands.
  2.  
  3. Remove the exhaust pipe-to-manifold bolts, then lower the vehicle.
  4.  
  5. Place a jack under the front crossmember of the cradle, then raise the jack until it starts to raise the vehicle and remove the two front body mount bolts.
  6.  
  7. With the cushions removed, thread the body mount bolts and retainers at least three turns into the cage nuts, then slowly release the jack.
  8.  
  9. Remove the power steering pump and bracket, then move it aside.
  10.  
  11. Disconnect the oxygen sensor connector.
  12.  
  13. Remove the crossover pipe-to-manifold nuts and the exhaust manifold bolts.
  14.  
  15. Remove the manifold and gasket.
  16.  
  17. To install, reverse the removal procedures.
  18.  
  19. Clean all the gasket surfaces completely.
  20.  

3.1L Engine (VIN T)

See Figure 4

LEFT SIDE
  1. Disconnect the negative battery cable.
  2.  
  3. Loosen and remove the air supply plumbing from the exhaust manifold, as required.
  4.  
  5. Remove the coolant recovery bottle, if necessary.
  6.  
  7. Remove the serpentine belt cover and belt, as required.
  8.  
  9. Remove the air conditioning compressor and lay aside, if necessary.
  10.  
  11. Remove the right side torque strut, air conditioning and torque strut mounting bracket, as required.
  12.  
  13. Disconnect the heat shield, if equipped.
  14.  
  15. Separate the exhaust crossover pipe at the manifold.
  16.  
  17. Remove the exhaust manifold retaining bolts, then the manifold and gasket.
  18.  

To install:
  1. Clean all the gasket surfaces completely.
  2.  
  3. Attach the exhaust manifold and gasket to the vehicle with the retaining bolts. Tighten to 15-20 ft. lbs. (20-30 Nm).
  4.  
  5. Attach the exhaust crossover pipe at the manifold, then tighten the mounting nuts to 18 ft. lbs. (25 Nm).
  6.  
  7. Install the heat shield, if equipped.
  8.  
  9. If removed, install the right side torque strut, air conditioning and torque strut mounting bracket.
  10.  
  11. If removed, install the air conditioning compressor.
  12.  
  13. If removed, install the serpentine belt and cover.
  14.  
  15. If removed, attach the coolant recovery bottle.
  16.  
  17. Install the air supply plumbing to the exhaust manifold.
  18.  
  19. Connect the negative battery cable.
  20.  



Click image to see an enlarged view

Fig. Fig. 4: Left and right side exhaust manifolds used on 3.1L engines

RIGHT SIDE
  1. Disconnect the negative battery cable.
  2.  
  3. Raise and safely support the vehicle.
  4.  
  5. Disconnect the exhaust pipe and lower the vehicle.
  6.  
  7. Remove the air cleaner assembly, breather, mass air flow sensor and heat shield.
  8.  
  9. Remove the crossover at the manifold.
  10.  
  11. Remove the accelerator and TV cables and brackets, as required.
  12.  
  13. Remove the exhaust manifold retaining bolts, then remove the manifold and gasket.
  14.  

To install:
  1. Clean all the gasket surfaces completely.
  2.  
  3. Install the exhaust manifold, gasket and retaining bolts. Tighten to 15-20 ft. lbs. (20-30 Nm).
  4.  
  5. If removed, install the accelerator, TV cables and brackets.
  6.  
  7. Install the crossover at the manifold.
  8.  
  9. Install the air cleaner assembly, breather, mass air flow sensor and heat shield.
  10.  
  11. Raise and safely support the vehicle.
  12.  
  13. Connect the exhaust pipe and lower the vehicle.
  14.  
  15. Connect the negative battery cable.
  16.  

3.1L Engine (VIN M)

See Figure 4

FRONT
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the top half of the air cleaner assembly and throttle cable duct.
  4.  
  5. Partially drain the cooling system.
  6.  
  7. Separate the radiator hose from the thermostat housing.
  8.  
  9. Remove the coolant bypass hose at the coolant pump and from the exhaust manifold.
  10.  
  11. Loosen and remove the exhaust crossover heat shield.
  12.  
  13. Remove the exhaust crossover pipe from the manifold.
  14.  
  15. Tag and disconnect the secondary ignition wires from the spark plugs.
  16.  
  17. Remove the exhaust manifold heat shield.
  18.  
  19. Unsecure the exhaust manifold retaining nuts.
  20.  
  21. Remove the exhaust manifold and gasket.
  22.  

To install:
  1. Clean mating surfaces at the cylinder head and manifold.
  2.  
  3. Install the exhaust manifold gasket and the exhaust manifold. Tighten the manifold mounting nuts to 12 ft. lbs. (16 Nm).
  4.  
  5. Attach the exhaust manifold heat shield.
  6.  
  7. Install the exhaust crossover pipe to the manifold.
  8.  
  9. Attach the exhaust crossover pipe heat shield.
  10.  
  11. Connect the secondary ignition wires to the appropriate spark plug.
  12.  
  13. Connect the coolant bypass pipe to the coolant pump and exhaust manifold.
  14.  
  15. Secure the radiator hose to the coolant outlet housing.
  16.  
  17. Install the top half of the air cleaner and the throttle body duct.
  18.  
  19. Connect the negative battery cable.
  20.  

REAR
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the top half of the air cleaner assembly and throttle cable duct.
  4.  
  5. Remove the exhaust crossover heat shield.
  6.  
  7. Separate the exhaust crossover pipe from the manifold.
  8.  
  9. Remove the oxygen sensor.
  10.  
  11. Separate the EGR pipe from the exhaust manifold.
  12.  
  13. Raise and safely support the vehicle.
  14.  
  15. Remove the transaxle oil fill tube and lever indicator assembly.
  16.  
  17. Disassemble the front exhaust pipe from the exhaust manifold.
  18.  
  19. Disconnect the exhaust pipe from the converter flange and support the converter.
  20.  
  21. Remove the converter heat shield from the body.
  22.  
  23. Loosen and remove the exhaust manifold heat shield.
  24.  
  25. Unsecure the exhaust manifold nuts.
  26.  
  27. Remove the exhaust manifold from the bottom of vehicle and the gasket.
  28.  

To install:
  1. Clean mating surfaces at the cylinder head and manifold.
  2.  
  3. Install the exhaust manifold gasket.
  4.  
  5. Install the exhaust manifold loosely and install heat shield at this time.
  6.  
  7. Install the manifold nuts, then tighten to 12 ft. lbs. (16 Nm).
  8.  
  9. Install the exhaust manifold heat shield nuts.
  10.  
  11. Install the converter heat shield to the body.
  12.  
  13. Connect the exhaust pipe to the converter flange.
  14.  
  15. Connect the exhaust pipe to the exhaust manifold.
  16.  
  17. Install the transaxle oil level indicator and fill tube assembly.
  18.  
  19. Safely lower the vehicle.
  20.  
  21. Connect the oxygen sensor.
  22.  
  23. Connect the EGR pipe to exhaust manifold.
  24.  
  25. Install top half of the air cleaner assembly and throttle body duct.
  26.  
  27. Connect the negative battery cable.
  28.  

3.3L Engine
LEFT SIDE
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air cleaner inlet ducting. Install the spark plug wires.
  4.  
  5. Loosen and remove the 2 bolts attaching the exhaust crossover pipe to the manifold.
  6.  
  7. Remove the engine lift hook, manifold heat shield and oil level indicator.
  8.  
  9. Remove the exhaust manifold retaining bolts and remove the manifold.
  10.  

To install:
  1. Clean all the gasket surfaces completely.
  2.  
  3. Install the exhaust manifold and retaining bolts, then tighten to 30 ft. lbs. (41 Nm).
  4.  
  5. Install the engine lift hook, manifold heat shield and oil level indicator.
  6.  
  7. Secure the 2 bolts attaching the exhaust crossover pipe to the manifold.
  8.  
  9. Install the air cleaner inlet ducting. Install the spark plug wires.
  10.  
  11. Connect the negative battery cable.
  12.  

RIGHT SIDE
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the spark plug wires, oxygen sensor connector, throttle cable bracket and cables.
  4.  
  5. Remove the brake booster hose from the manifold.
  6.  
  7. Unsecure the 2 bolts attaching the exhaust crossover pipe to the manifold.
  8.  
  9. Remove the exhaust pipe-to-manifold bolts, engine lift hook and transaxle oil level indicator tube.
  10.  
  11. Remove the manifold heat shield. Remove the exhaust manifold retaining bolts and remove the manifold.
  12.  

To install:
  1. Clean all the gasket surfaces completely.
  2.  
  3. Install the exhaust manifold and retaining bolts, then tighten to 30 ft. lbs. (41 Nm). Install the manifold heat shield.
  4.  
  5. Install the exhaust pipe-to-manifold bolts, engine lift hook and transaxle oil level indicator tube.
  6.  
  7. Secure the 2 bolts attaching the exhaust crossover pipe to the manifold.
  8.  
  9. Attach the brake booster hose to the manifold.
  10.  
  11. Install the spark plug wires, oxygen sensor connector, throttle cable bracket and cables.
  12.  
  13. Connect the negative battery cable.
  14.  

3.8L Engine
  1. Disconnect the negative battery cable.
  2.  


WARNING
Failure to disconnect the intermediate shaft from the rack and pinion stub shaft may result in damage to the steering gear and/or intermediate shaft.

  1. Remove the pinch bolt from the intermediate shaft and separate the intermediate shaft from the stub shaft.
  2.  
  3. Raise and safely support the vehicle.
  4.  
  5. Remove the 2 bolts attaching the exhaust pipe to the manifold.
  6.  
  7. Lower the vehicle.
  8.  
  9. Remove the upper engine support strut.
  10.  
  11. Place a jack under the front crossmember of the cradle and raise the jack until it starts to raise the vehicle.
  12.  
  13. Remove the 2 front body mount bolts.
  14.  
  15. With the cushions removed, thread the body mount bolts and retainers a minimum of 3 turns into the cage nuts.
  16.  
  17. Release the jack slowly.
  18.  

To avoid damage, do not lower the cradle without it being restrained.

  1. Remove the power steering pump and bracket from the cylinder head and exhaust manifold.
  2.  
  3. Disconnect the oxygen sensor.
  4.  
  5. If removing the left side exhaust manifold, remove the upper engine support strut.
  6.  
  7. Remove the 2 nuts retaining the crossover pipe to the exhaust manifold.
  8.  
  9. Remove the 6 bolts attaching the manifold to the cylinder head.
  10.  
  11. Remove the exhaust manifold.
  12.  

To install:
  1. Carefully, clean the gasket sealing surfaces of old gasket material.
  2.  
  3. Install the exhaust manifold and the manifold-to-cylinder head bolts, then tighten to 37 ft. lbs. (50 Nm).
  4.  
  5. If the left side exhaust manifold was removed, install the crossover pipe to the manifold.
  6.  
  7. If the right side exhaust manifold was removed, install the upper engine support strut.
  8.  
  9. Connect the oxygen sensor wire.
  10.  
  11. Install the power steering pump and bracket.
  12.  
  13. Support the cradle with the jack. Remove the 2 body mount bolts and install the cushions.
  14.  
  15. Raise the cradle into position and install the 2 body mount bolts.
  16.  
  17. Remove the jack.
  18.  
  19. Connect the intermediate shaft to the stub shaft and install the pinch bolt.
  20.  
  21. Raise and safely support the vehicle.
  22.  
  23. Install the exhaust pipe-to-manifold bolts.
  24.  
  25. Lower the vehicle.
  26.  
  27. Connect the negative battery cable.
  28.  

4.3L Diesel Engine
LEFT SIDE

See Figure 5

  1. Remove the upper exhaust crossover pipe-to manifold bolts. Loosen the lower crossover pipe bolt at the right rear exhaust manifold.
  2.  
  3. Raise and support the car on jackstands.
  4.  
  5. Remove the remaining left front crossover pipe-to-manifold bolt. Unbolt and remove the manifold and gasket.
  6.  



Click image to see an enlarged view

Fig. Fig. 5: Locktabs are used to secure the exhaust manifold bolts

To install:
  1. Clean all the gasket surfaces completely.
  2.  
  3. Lubricate the entire exhaust manifold-to-cylinder head bolts with lubricant GM part no. 1052080 or equivalent.
  4.  
  5. Attach the new manifold and gasket to the vehicle, tighten the bolts to 29 ft. lbs. (39 Nm).
  6.  
  7. Bend the locktabs over the bolt heads.
  8.  
  9. Install the left front crossover pipe bolt, lower the vehicle.
  10.  
  11. Attach the lower crossover pipe bolt at the right rear exhaust manifold.
  12.  
  13. Install the upper exhaust crossover pipe-to manifold bolts.
  14.  

RIGHT SIDE

See Figure 6

  1. Remove the engine support strut.
  2.  
  3. Place a floor jack under the front crossmember and take up the weight of the car.
  4.  
  5. Remove the two front body mount bolts. Remove the cushions from the bolts.
  6.  
  7. Thread the body mount bolts with their retainers into the cage nuts so that the bolts restrict movement of the engine cradle.
  8.  



Click image to see an enlarged view

Fig. Fig. 6: Right (rear) exhaust manifold used on 4.3L engines

  1. Lower the jack until the crossmember contacts the body mount bolt retainers. Check for any hose or wire interference.
  2.  
  3. Remove the crossover pipe.
  4.  
  5. Raise and support the car on jackstands.
  6.  
  7. Disconnect the exhaust pipe from the manifold.
  8.  
  9. Lower the car.
  10.  
  11. Unbolt and remove the manifold and gasket.
  12.  
  13. Installation is the reverse of removal. Lubricate the entire length of each manifold bolt with lubricant GM part no. 1052080 or its equivalent.
  14.  

 
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