Removal Procedure

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

During disassembly, ensure that the valve lifters are kept together and identified so that they can be reinstalled in the original locations.

Before disassembling the valve mechanism, make a compression test and note the results. Refer to Engine Compression Test .

1. Disconnect the negative battery cable.
2. Remove the ignition coil and the module assembly.
Fig 1: Ignition Coil & Module Assembly
Courtesy of GENERAL MOTORS CORP.
3. Disconnect the timing chain housing at the exhaust camshaft housing but do not remove from the parts from the vehicle. Refer to TIMING CHAIN HOUSING -- REMOVAL .
4. Remove the exhaust camshaft end cover and gasket.
   Fig 2: Exhaust Camshaft End Cover And Gasket

   Courtesy of GENERAL MOTORS CORP.
5. Remove the exhaust camshaft housing to the cylinder head bolts.
   Fig 3: Exhaust Camshaft Housing To The Cylinder Head Bolts

   Courtesy of GENERAL MOTORS CORP.
6. Use the reverse of the tightening procedure when loosening the camshaft housing to the cylinder head retaining bolts.
Fig 4: Camshaft Housing-To-Cylinder Head Retaining Bolt Tightening Sequence
Courtesy of GENERAL MOTORS CORP.
7. Leave two bolts loosely in place in order to hold the camshaft housing while separating the camshaft cover from the housing.

   Important:  Tighten the bolts in evenly in order to prevent the cover from binding on the dowel pins.

8. Push the cover off the housing by threading the four of the housing to head retaining bolts into the tapped holes in the camshaft cover.
9. Remove the two loosely installed camshaft housing to head bolts.
10. Remove the cover.
11. Discard the gaskets.
12. Loosely reinstall the one camshaft housing to the cylinder head bolt in order to retain the housing during the camshaft and the lifter removal.
13. Notice the position of the chain sprocket dowel pin for reassembly. Remove the camshaft carefully in order to prevent damage to the camshaft or the journals.
14. Remove the valve lifters.

    Keep the lifters in order so that the lifters can be reinstalled in the original location.

    Important: 

    • These lifters are not serviceable. Replace any faulty lifters.
    • Coat the lifter with Camshaft and Lifter Prelube GM P/N 12345501 (Canadian P/N 992704) or the equivalent.

      If new lifters are installed, add the Engine Oil Supplement GM P/N 1052367 (Canadian P/N 992869) or the equivalent to the engine oil.

15. In order to minimize lifter bleed down, use the following procedure:
    • Store lifters upside down (the camshaft contact surface down) on a level surface.
    • Store the lifters submerged in clean engine oil.

    Important:  Ensure that the camshaft housing alignment dowel pins are in the cylinder head prior to installing the housing.

16. Remove the camshaft housing gasket.
    Fig 5: Camshaft Housing Gasket

    Courtesy of GENERAL MOTORS CORP.