Tools Required

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 .

Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

1. Disconnect the negative battery cable.
2. Remove the ignition coil and the module. Refer to Ignition Coil Replacement in Engine Controls - 2.4L.



3. Remove the camshaft position sensor connector.



4. Remove the power steering pump 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. Remove the fuel line retaining clamp from the bracket on top of the intake camshaft housing.



7. Remove the retaining bolts which secure the fuel rail to the camshaft housing.
8. Remove the fuel rail from the cylinder head.
9. Cover the injector openings in the cylinder head.
10. Cover the injector nozzles.
11. Leave the fuel lines attached and position fuel rail aside (on top of the master cylinder).
12. Disconnect, but do NOT remove from the vehicle, the timing chain housing at the intake camshaft housing. Refer to Timing Chain Housing Replacement



13. Remove the retaining bolts which secure the camshaft housing cover to the camshaft housing.




Important: 

•	Use the reverse of the tightening procedure in order to loosen the retaining bolts which secure the camshaft housing to the cylinder head.

•	Leave 2 bolts loosely in place in order to hold the camshaft housing while separating the camshaft cover from the housing.

14. Remove the retaining bolts which secure the camshaft housing to the cylinder head.

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

15. Push the cover off the housing by threading 4 bolts, which secure the housing to the head, into the tapped holes in the camshaft housing cover.
16. Remove the 2 loosely-installed bolts which secure the camshaft housing to the head.



17. Remove the cover and discard the gaskets.
18. Loosely reinstall 1 bolt, which secures the camshaft housing to the cylinder head, in order to retain the housing during the camshaft and lifter removal.



19. Note the position of the chain sprocket dowel pin for reassembly.



20. Remove the camshaft, being careful not to damage the camshaft or the journals.




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

21. Remove the valve lifters.
22. Keep the lifters in order, opposite to their installed position.

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

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

This will minimize the lifter bleed down.




24. 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.
25. Inspect the following camshaft components for damage:

•	The sprocket

•	The keyway and the threads

•	The camshaft position sensor reluctor

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

•

Wear

•

Galling

•

Gouges

•	Overheating or discoloration

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

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

Sealer is unnecessary.

2. Loosely install the cylinder head bolt on camshaft housing 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 you installed a new camshaft, add Engine Oil Supplement GM P/N 1052367 or the equivalent to the engine oil.

•	Coat the entire camshaft with Camshaft and Lifter 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 the 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 cover to the camshaft housing.




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

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.

9. Install the bolts securing the camshaft housing to the cylinder head.

Rotate the bolts in sequence by the amount of degrees specified.

Tighten
Using J 36660-A , tighten the bolts to 22 N·m (16 lb ft) + 90 degrees.

10. Install the bolts which secure the camshaft housing cover to the camshaft housing.

Rotate the bolts in sequence by the amount of degrees specified.

Tighten
Using J 36660-A , tighten to 22 N·m (16 lb ft) + 30 degrees.

11. Install the timing chain housing and install the timing chain. Refer to Timing Chain Housing Replacement
12. Uncover the fuel injectors and install the new injector O-ring seals.

Lubricate the O-ring seals with engine oil.




13. Uncover the injector openings in the cylinder head and install the fuel rail onto the cylinder head.
14. Install the bolts which secure the fuel rail to the camshaft housing.

Tighten
Tighten the camshaft housing bolts to 26 N·m (19 lb ft).




15. Install the fuel line retaining clamp and the retainer to the bracket on top of the camshaft housing.



16. Install the vacuum line to the fuel pressure regulator.
17. Install the fuel injector harness connector.
18. Install the camshaft position sensor connector.




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.

19. Install the power steering pump assembly.
20. If any spark plug boot connector assembly has stuck to a spark plug, reinstall the connector onto the ignition coil and the module assembly.



21. Position the ignition coil and the module assembly over the spark plugs and push straight down.
22. Clean any loose lubricant from the ignition coil and from the bolts which secure the module assembly to the camshaft housing.
23. Apply pipe sealant GM P/N 1052080 or the equivalent onto the ignition coil and onto the bolts which secure the module cover assembly to the camshaft housing.

Tighten
Tighten the bolts to 15 N·m (11 lb ft) + 30 degrees.

24. 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:

24.1.

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

24.2.

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

24.3.

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

25. Install the electrical connector to the ignition coil and to the module. Refer to Ignition Coil Replacement in Engine Controls - 2.4L.
26. Connect the negative battery cable.