If you loosen or remove the bolts which secure the camshaft housing
to the cylinder head, replace the gasket between the camshaft housing and the cylinder head. During disassembly, keep the valve
lifters together and identified, so that you can reinstall the lifters in the original locations.
1. Before disassembling the valve mechanism, make a compression test and note the results. Caution: Refer to Battery Disconnect Caution in Service Precautions.
2. Disconnect the negative battery cable.
3. Disconnect the ignition coil and the module assembly electrical connection.
4. Remove the ignition coil bolts. Remove the bolts securing the module assembly to the camshaft housing.
5. Remove the assembly by pulling straight up.
6. The connector assembly may be stuck to the spark plugs. Use J 36011 by first twisting then pulling upward on the connector assembly.
7. Disconnect the electrical connection from the oil pressure switch.
8. Disconnect the timing chain
housing at the exhaust camshaft housing, but do NOT remove the parts from the vehicle.
9. Remove the exhaust camshaft cover and the gasket.
10. Install the cover to the camshaft housing.
11. Use the J 36660-A in order to install the bolts.
^ Tighten the bolts which secure the camshaft housing to the cylinder head to 15 Nm (11 ft. lbs.) + 90 degrees.
^ Tighten the bolts which secure the camshaft housing cover to the camshaft housing to 15 Nm (11 ft. lbs.) + 30 degrees.
12. Install the timing chain housing to the camshaft housing and the timing chain. Refer to Timing Chain Housing Replacement.
13. Install the exhaust camshaft housing cover and the new gasket.
14. Connect the electrical connection to the oil pressure switch.
15. If any spark plug boot connector assembly is stuck to a spark plug, reinstall the connector onto the ignition coil and the module assembly.
16. Locate the ignition coil and the module assembly over the spark plugs.
17. Push straight down.
18. Clean any lubricant from the ignition coil and the bolts which secure the module assembly to the camshaft housing.
19. Apply pipe sealant GM P/N 1052080 or the equivalent onto the ignition coil and onto the bolts which secure the module assembly to the camshaft housing.
^ Tighten the bolts to 15 Nm (11 ft. lbs.) + 30 degrees.
20. Connect the electrical connector to the ignition coil and to the module assembly.
21. Connect the negative battery cable. Important:
Do not compress the lifter plungers using a vise or other tool. This will cause more air to enter the lifter assembly and will take more time to bleed out once the lifters are installed.
22. If you have installed new lifter or if the lifters bled down while the engine was disassembled, you may experience excessive lifter noise. This is a normal condition and no engine damage is occurring. Use the following procedure in order to purge the air from the lifters:
22.1. Start the engine and warm the engine at the idle for 5 minutes.
22.2. Increase the engine speed to 2000 RPM until the lifter noise is gone.
22.3. Return the engine to idle for an additional 5 minutes or perform a road test.
23. Start the engine. Inspect for leaks.