GM Malibu/Cutlass 1997-2000

Camshaft, Bearings and Lifters

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REMOVAL & INSTALLATION



2.4L Engine
INTAKE CAMSHAFT

NOTE
Any time the camshaft housing to cylinder head bolts are loosened or removed, the camshaft housing to cylinder head gasket must be replaced.

  1. Relieve the fuel system pressure, as outlined in . Disconnect the negative battery cable.
  2.  
  3. Label and detach the ignition coil and module assembly electrical connections.
  4.  
  5. Unfasten the ignition coil and module assembly to camshaft housing bolts, then remove the assembly by pulling straight up. Use a special spark plug boot wire remover tool to remove connector assemblies, if they have stuck to the spark plugs.
  6.  



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Fig. View of the ignition coil and module assembly

  1. If equipped, remove the idle speed power steering pressure switch connector.
  2.  
  3. Loosen the three power steering pump pivot bolts and remove drive belt.
  4.  
  5. Disconnect the two rear power steering pump bracket-to-transaxle bolts.
  6.  
  7. Remove the front power steering pump bracket to cylinder block bolt.
  8.  
  9. Disconnect the power steering pump assembly, then position it aside. Do not disconnect the fluid lines.
  10.  
  11. Using the special tool, remove the power steering pump drive pulley from the intake camshaft.
  12.  
  13. Remove oil/air separator bolts and hoses. Leave the hoses attached to the separator, disconnect from the oil fill, chain housing and intake manifold. Remove as an assembly.
  14.  
  15. Remove vacuum line from fuel pressure regulator and detach the fuel injector harness connector.
  16.  
  17. Disconnect fuel line attaching clamp from bracket on top of intake camshaft housing.
  18.  
  19. Unfasten the fuel rail-to-camshaft housing attaching bolts, then remove the fuel rail from the cylinder head. Cover or plug injector openings in cylinder head and the injector nozzles. Leave the fuel lines attached, then position fuel rail aside.
  20.  



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Fig. Fuel injection rail assembly and related components

  1. Disconnect the timing chain and housing, but do NOT remove from the engine.
  2.  
  3. Remove the intake camshaft housing cover-to-camshaft housing attaching bolts.
  4.  
  5. Unfasten the intake camshaft housing-to-cylinder head attaching bolts. Use the reverse of the tightening sequence (shown the accompanying figure) when loosening the bolts. Leave two of the bolts loosely in place to hold the camshaft housing while separating the camshaft cover from housing.
  6.  
  7. Push the cover off the housing by threading four of the housing-to-head attaching bolts into the tapped holes in the cam housing cover. Tighten the bolts evenly so the cover does not bind on the dowel pins.
  8.  
  9. Remove the two loosely installed camshaft housing to head bolts and remove the cover. Discard the gaskets.
  10.  
  11. Note the position of the chain sprocket dowel pin for reassembly.
  12.  
  13. Remove the intake camshaft oil seal from the camshaft and discard the seal. This seal must be replaced any time the housing and cover are separated.
  14.  
  15. Remove the camshaft carrier from the cylinder head and remove the gasket. Discard the gasket.
  16.  

To install:

  1. Thoroughly clean the mating surfaces of the camshaft carrier and the cylinder head, bolts and bolt holes. Install a new gasket and place the housing on the head. Install one bolt loosely to hold it in place.
  2.  
  3. Install the lifters into their bores. If the camshaft is being replaced, the lifters must also be replaced. Lubricate camshaft lobes, journals and lifters with camshaft and lifter prelube. The camshaft lobes and journals must be adequately lubricated or engine damage could occur upon start up.
  4.  
  5. Install the camshaft in the same position as when removed. The timing chain sprocket dowel pin should be straight up and align with the centerline of the lifter bores.
  6.  
  7. Install new camshaft housing to camshaft housing cover seals into cover; do not use sealer. Make sure the correct color seal is placed in each groove. Install the cover to the housing.
  8.  



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Fig. View of the intake and exhaust camshaft-to-housing seal placement

  1. Apply thread locking compound to the camshaft housing and cover attaching bolt threads.
  2.  
  3. Install the bolts, then tighten to 11 ft. lbs. (15 Nm). Rotate the bolts (except the two rear bolts that hold the fuel pipe to the camshaft housing) an additional 75°, in sequence. Tighten the two rear bolts to 16 ft. lbs. (15 Nm), then rotate an additional 25°.
  4.  



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Fig. Intake and exhaust camshaft housing bolt tightening sequence

  1. Install the timing chain housing and the timing chain.
  2.  
  3. Uncover fuel injectors, then install new fuel injector O-ring seals lubricated with oil. Install the fuel rail.
  4.  
  5. Fasten the fuel line attaching clamp and retainer to bracket on top of the intake camshaft housing.
  6.  
  7. Connect the vacuum line to the fuel pressure regulator.
  8.  
  9. Attach the fuel injectors harness connector.
  10.  
  11. Install the oil/air separator assembly.
  12.  
  13. Lubricate the inner sealing surface of the intake camshaft seal with oil and install the seal to the housing.
  14.  
  15. Install the power steering pump pulley onto the intake camshaft.
  16.  
  17. Install the power steering pump assembly and drive belt.
  18.  
  19. Attach the idle speed power steering pressure switch connector.
  20.  
  21. Clean any extra lubricant that is present on the ignition coil and module assembly to camshaft housing bolts. Apply an appropriate thread sealing compound onto the ignition coil and module assembly to camshaft housing bolts. Install the bolts and tighten to 13 ft. lbs. (18 Nm).
  22.  
  23. Attach the electrical connectors to ignition coil and module assembly.
  24.  
  25. Connect the negative battery cable, then start the engine and check for leaks.
  26.  

EXHAUST CAMSHAFT

NOTE
Any time the camshaft housing-to-cylinder head bolts are loosened or removed, the camshaft housing to cylinder head gasket must be replaced.

  1. Relieve the fuel system pressure, as outlined in . Disconnect the negative battery cable.
  2.  
  3. Label and disconnect the ignition coil and module assembly electrical connections.
  4.  
  5. Unfasten the ignition coil and module assembly-to-camshaft housing bolts, then remove the assembly by pulling straight up. Use a special tool to remove connector assemblies if they have stuck to the spark plugs.
  6.  
  7. If equipped, remove the idle speed power steering pressure switch connector.
  8.  
  9. Remove the transaxle fluid level indicator tube assembly from exhaust camshaft cover and position aside.
  10.  
  11. Remove exhaust camshaft cover and gasket.
  12.  
  13. Disconnect the timing chain and housing but do not remove from the engine.
  14.  
  15. Remove exhaust camshaft housing to cylinder head bolts. Use the reverse of the tightening procedure when loosening camshaft housing while separating camshaft cover from housing.
  16.  
  17. Push the cover off the housing by threading four of the housing to head attaching bolts into the tapped holes in the camshaft cover. When threading the bolt, tighten them evenly so the cover does not bind on the dowel pins.
  18.  
  19. Remove the two loosely installed camshaft housing to cylinder head bolts and remove cover, discard gaskets.
  20.  
  21. Loosely reinstall one camshaft housing to cylinder head bolt to retain the housing during camshaft and lifter removal.
  22.  
  23. Note the position of the chain sprocket dowel pin for reassembly. Remove camshaft being careful not to damage the camshaft or journals.
  24.  
  25. Remove the camshaft carrier from the cylinder head and remove the gasket. Discard the gasket.
  26.  

To install:

  1. Thoroughly clean the mating surfaces of the camshaft carrier and the cylinder head, bolts and bolt holes. Install a new gasket and place the housing on the head. Install 1 bolt loosely to hold in place.
  2.  
  3. Install the lifters into their bores. If the camshaft is being replaced, the lifters must also be replaced. Lubricate camshaft lobes, journals and lifters with camshaft and lifter prelube. The camshaft lobes and journals must be adequately lubricated or engine damage could occur upon start up.
  4.  
  5. Install camshaft in same position as when removed. The timing chain sprocket dowel pin should be straight up and align with the centerline of the lifter bores.
  6.  
  7. Install new camshaft housing-to-camshaft housing cover seals into the cover; do not use sealer. Make sure the correct color seal is placed in each groove. Install the cover to the housing.
  8.  
  9. Apply thread locking compound to the camshaft housing and cover attaching bolt threads.
  10.  
  11. Install the bolts, tighten in sequence to 11 ft. lbs. (15 Nm), then rotate the bolts an additional 75 °, in sequence.
  12.  
  13. Install timing chain housing and timing chain.
  14.  
  15. Install the transaxle fluid level indicator tube assembly to the exhaust camshaft cover.
  16.  
  17. Attach the idle speed power steering pressure switch connector.
  18.  
  19. Clean any extra lubricant that is present on the ignition coil and module assembly to camshaft housing bolts. Apply an appropriate thread sealing compound onto the ignition coil and module assembly to camshaft housing bolts. Install the bolts and tighten to 124 inch lbs. (14 Nm).
  20.  
  21. Attach the electrical connectors to ignition coil and module assembly.
  22.  
  23. Connect the negative battery cable, then start the engine and check for leaks.
  24.  

3.1L Engine

NOTE
The camshaft bearings can not be reused once removed from the engine.

  1. Relieve the fuel system pressure, as outlined in .
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Remove the engine from the vehicle and secure to a suitable holding fixture.
  6.  


NOTE
When removing valve train components, they must be marked for installation in the same location they are removed from. When the camshaft is being replaced, the valve lifters should also be replaced.

  1. Remove the intake manifold, valve cover, rocker arms, pushrods and valve lifters.
  2.  
  3. Remove the crankshaft balancer and front cover.
  4.  
  5. Remove the timing chain and sprockets.
  6.  
  7. Unfasten the oil pump driven gear mounting bolt, then remove the oil pump driven gear.
  8.  
  9. Remove the two bolts, then remove the camshaft thrust plate.
  10.  
  11. Carefully remove the camshaft. Avoid marring the camshaft bearing surfaces.
  12.  
  13. To remove the camshaft bearings, select the proper expander assembly.
    1. Assemble the bearing tool.
    2.  
    3. Carefully tap out the bearings.
    4.  

  14.  


NOTE
The camshaft bearings can not be reused once removed from the engine.

To install:

  1. Select the front, rear and intermediate camshaft bearings.
    1. Select the proper expander assembly.
    2.  
    3. Place the bearing into the tool and index the oil holes of the bearing with the oil passages of the cylinder block. Tap the bearing carefully into place. Looking from the front of the engine block, index the front bearing oil holes at 4 and 7 o'clock.
    4.  

  2.  



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Fig. Inspecting the camshaft bearing oil hole alignment



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Fig. Using the proper tool to removal and/or install camshaft bearings-3.1L engine shown

  1. Index all other bearings oil holes at 4 o'clock.
  2.  
  3. With a piece of brass rod 3 / 32 inch and a 90° bend at the end, probe the bearing oil holes and verify that they are properly aligned.
  4.  

  1. Coat the camshaft with lubricant, and install the camshaft.
  2.  



Click image to see an enlarged view

Fig. Install the camshaft with a large screwdriver or other suitable tool inserted into the camshaft bolt hole located on the gear end of the camshaft

  1. Install the camshaft thrust plate, then tighten the mounting bolts to 89 inch lbs. (10 Nm).
  2.  



Click image to see an enlarged view

Fig. Lubricate the end of the camshaft then install the thrust plate

  1. Install the oil pump driven gear, then tighten the mounting bolt to 27 ft. lbs. (36 Nm).
  2.  
  3. Install the timing chain and sprocket.
  4.  
  5. Install the camshaft thrust button and front cover.
  6.  
  7. Install the crankshaft balancer.
  8.  
  9. Install the intake manifold, valve cover, rocker arms, pushrods and valve lifters.
  10.  
  11. Install the engine assembly into the vehicle.
  12.  
  13. Connect the negative battery cable.
  14.  
  15. Adjust the valves, as required.
  16.  
  17. Start the engine and verify that there are no oil leaks.
  18.  

INSPECTION





Click image to see an enlarged view

Fig. Measuring camshaft lobe lift



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Fig. Measuring camshaft run-out



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Fig. Measuring camshaft straightness

Using solvent, degrease the camshaft and clean out all of the oil holes. Visually inspect the cam lobes and bearing journals for excessive wear. If a lobe is questionable, check all of the lobes as indicated. If a journal or lobe is worn, the camshaft MUST BE replaced.


NOTE
If a journal is worn, there is a good chance that the bearings or journals are worn and need replacement.

If the lobes and journals appear intact, place the front and rear journals in V-blocks and rest a dial indicator on the center journal. Rotate the camshaft to check the straightness. If deviation exceeds 0.001 in. (0.0254mm), replace the camshaft.

Check the camshaft lobes with a micrometer, by measuring the lobes from the nose to the base and again at 90° (see illustration). The lobe lift is determined by subtracting the second measurement from the first. If all of the exhaust and intake lobes are not identical, the camshaft must be reground or replace.

 
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