For 1990-2009 cars

#### Tools Required

• | J 36660-A Torque Angle Meter

• | J 36011 Spark Plug Wire Remover

### Removal Procedure

Important:

• | Whenever you loosen or remove the bolts which secure the camshaft housing to the cylinder head, replace gasket between the camshaft housing and the cylinder head.

• | 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. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
2. Remove the ignition coil and the module. Refer to Ignition Control Module Replacement in Engine Controls - 2.4 L.
3. Disconnect the camshaft position sensor electrical connector.
4. Remove the power steering pump bolts and position aside.

Do NOT disconnect the power steering lines.

5. Remove the vacuum line from the fuel pressure regulator and the fuel injector harness connector.
6. Disconnect oil pressure switch.
7. Remove fuel rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls.
8. Disconnect, but do NOT remove from the vehicle, the timing chain housing at the intake camshaft housing. Refer to Timing Chain Housing Replacement .
9. Remove the camshaft housing cover bolts.

Important:

• | Use the reverse order of the tightening procedure in order to loosen the camshaft housing bolts.

• | Leave two bolt loosely in place in order to hold the camshaft housing while separating the camshaft housing cover from the housing.

10. Remove the camshaft housing bolts.
11. Push the cover off the housing by threading four bolts, which secure the housing to the head, into the tapped holes in the camshaft housing cover.
12. Remove the two loosely-installed bolts which secure the camshaft housing to the head.
13. Remove the camshaft housing cover and discard the gaskets.
14. Loosely reinstall one bolt, which secures the camshaft housing to the cylinder head, in order to retain the housing during the camshaft and lifter removal.
15. Note the position of the timing chain sprocket dowel pin for reassembly.
16. Remove the camshaft, being careful not to damage the camshaft or the journals.

Important: The valve lifters are not serviceable. Replace faulty valve lifters.

17. Remove the valve lifters.
18. Keep the lifters in order, opposite to their installed position.

This will ease in reinstalling the lifters to their original locations.

19. Store the lifters upside down in clean engine oil, on a level surface.

This will minimize the lifter bleed down.

20. Remove the camshaft housing and the gasket.

Important: Replace a damaged camshaft. Do NOT attempt to repair the camshaft.

If a new camshaft is installed, replace all of the valve lifters which are actuated by the camshaft.
21. Inspect the following camshaft components for damage:

• | The sprocket

• | The keyway and the threads

• | The camshaft position sensor reluctor

22. Inspect the camshaft bearing surfaces and the camshaft lobes for the following damage:

• | Wear

• | Galling

• | Gouges

• | Overheating or discoloration

23. Measure the bearing journals diameter with a micrometer. If out of specification, replace the camshaft.

### Installation Procedure

1. Install the camshaft housing to the cylinder head with a new gasket.

Sealer is unnecessary.

2. Loosely install a camshaft housing to cylinder head bolt in order to hold the housing in place.

Notice: The camshaft lobes and the journals must be adequately lubricated or serious engine damage will occur upon start up.

Important: Return all used lifters to the original position in the camshaft housing. If you replace the camshaft, replace the lifters which are actuated by the camshaft.

3. Install the lifters into the lifter bores.
4. Install the camshaft in the same position as removed.

Set the timing chain sprocket dowel pin straight up. Align the pin with the centerline of the lifter bores.

Important:

• | If installing a new camshaft, add engine oil supplement GM P/N 1052367 or the equivalent to the engine oil.

• | Coat the entire camshaft with prelube GM P/N 12345501 or the equivalent.

5. Install the new camshaft housing to the green-colored cover seals and into the cover.

Sealant is unnecessary.

6. Remove the bolt holding the housing in place.
7. Apply pipe sealant GM P/N 1052080 or the equivalent to the camshaft housing and to the threads of the cover retaining bolt.
8. Install the camshaft housing cover to the camshaft housing.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Important: The top intake camshaft housing bolts are tightened to a different specification than the other camshaft housing bolts.

9. Install the camshaft housing to cylinder head bolts.

Tighten
Tighten the camshaft housing bolts to 15 N·m (11 lb ft). Using the J 36660-A torque the bolts an additional 90 degrees.

10. Install the camshaft housing cover bolts

Tighten
Tighten the camshaft housing cover bolts to 15 N·m (11 lb ft). Using the J 36660-A , torque the bolts an additional 30 degrees.

11. Install the timing chain housing and install the timing chain. Refer to Timing Chain Housing Replacement .
12. Install fuel rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls.
13. Install the vacuum line to the fuel pressure regulator.
14. Install the fuel injector harness connector.
15. Connect the camshaft position sensor electrical connector.
16. Connect oil pressure switch.

Important: When reinstalling the power steering pump, apply a 3 mm (¼ in) bead of GM P/N 12346286 sealer or the equivalent to the joint at the end of the camshaft housing halves before the installation of the power steering pump and the pump face seal.

17. Install the power steering pump bolts.
18. If any spark plug boot connector assembly has stuck to a spark plug, reinstall the connector onto the ignition coil and the module assembly.
19. Install the ignition coil and the module. Refer to Ignition Control Module Replacement in Engine Controls - 2.4L.
20. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
21. If new lifters have been installed or the lifters bled down while the engine was disassembled, excessive lifter noise may be experienced. This is a normal condition and no engine damage is occurring. Use the following procedure in order to purge air from the lifters:

21.1. | Start the engine and allow the engine to warm up at idle for 5 minutes.

21.2. | Increase the engine speed to 2,000 RPM until the lifter noise is gone.

21.3. | Return the engine to idle for an additional 5 minutes or perform a road test.