Intake Manifold Replacement - Lower
Intake Manifold Replacement - LowerRemoval Procedure
1. Disconnect the battery negative cable from the battery.
2. Remove the engine cover from the vehicle.
3. Remove the air cleaner assembly from the vehicle.
4. Remove the air intake duct from the turbocharger.
5. Remove the upper intake manifold bolts.
6. Remove the upper intake manifold.
7. Remove the gaskets from the lower intake manifold.
8. Remove the seal from the turbocharger.
Important: The lower intake comes in two sections. If replacing both the left side and the right side perform all of the following steps. If replacing only the left side perform steps 9 to 22 and step 42 to 44. If replacing only the right side perform steps 22 to 44.
9. Remove the transmission oil level indicator tube upper section from the upper intake manifold.
10. Remove the oil level indicator from the tube.
11. Remove the nut retaining the oil level indicator to the thermostat crossover.
12. Separate the upper section of the oil level indicator tube from the lower section.
13. If equipped with rear Air Conditioning (A/C), remove the rear A/C pipe from the A/C compressor.
14. Remove the nuts retaining the rear A/C pipe brackets from the upper intake manifold (if equipped).
15. Position the rear A/C pipe our of the way.
16. Drain the engine coolant.
17. Remove the upper radiator hose.
18. Disconnect the gray engine harness electrical connector.
19. Remove the electrical harness and retaining brackets from the upper intake manifold (if needed).
20. Remove the nuts retaining the fuel pipe brackets.
21. Remove the bracket for retaining the CDR valve from the right side lower intake manifold studs.
22. Remove the CDR valve.
Important: The sensors and the solenoids attached to the lower intake manifold require removal in order to prevent damage when cleaning with solvent cleaning.
23. Disconnect the Intake Air Temperature (IAT) sensor electrical connector.
24. Remove the IAT sensor.
25. Disconnect the Boost sensor electrical connector by releasing the locking tab.
26. Remove the Boost sensor retaining bolts.
27. Remove the Boost sensor.
28. Remove the gasket.
29. Disconnect the glow plug relay electrical connectors by releasing the locking tab.
30. Remove the hold down nuts on the glow plug relay power supply terminals.
31. Remove the glow plug relay power supply terminals.
32. Remove the glow plug relay retaining nuts.
33. Remove the glow plug relay.
34. Disconnect the wastegate solenoid wiring harness connector by releasing the locking tab.
35. Remove the vacuum hose harness.
36. Remove the wastegate solenoid retaining bolts.
37. Remove the wastegate solenoid.
38. Remove the wastegate solenoid mounting bracket retaining nuts.
39. Remove the wastegate solenoid mounting bracket.
40. Remove the electrical harness retaining clips.
41. Position the engine wiring harness out of the way.
42. Remove the lower intake manifold bolts.
43. Remove the lower intake manifold and gaskets from the cylinder heads.
44. Inspect and clean the sealing surfaces.
Installation Procedure
1. Install the new gaskets onto the cylinder heads.
2. Install the intake manifolds.
3. Apply teflon sealer GM P/N 1236004 on the threads of the studs that are second to the end on both intake manifolds. There are a total of four studs that require the teflon sealer.
4. Apply threadlocker GM P/N 12345382 on the threads of the remaining studs.
Notice: Refer to Fastener Notice in Service Precautions.
5. Install the intake manifold studs.
^ Tighten the intake manifold studs, (from the center out) to 42 Nm (31 ft. lbs.).
6. Install the miscellaneous brackets and fuel line brackets on the intake studs.
7. Install the nuts for the brackets.
^ Tighten the bracket nuts to 23 Nm (17 ft. lbs.).
8. Position the engine wiring harness.
9. Install the electrical harness in the retaining clips.
10. Install the wastegate solenoid mounting bracket.
11. Install the wastegate solenoid mounting bracket retaining nuts.
^ Tighten the bracket nuts to 23 Nm (17 ft. lbs.).
12. Install the wastegate solenoid.
13. Install the wastegate solenoid retaining bolts.
^ Tighten the wastegate solenoid bolts to 3.5 Nm (27 inch lbs.).
14. Connect the wastegate solenoid wiring harness connector.
15. Install the vacuum hose harness.
16. Install the glow plug relay.
17. Install the glow plug relay retaining nuts.
^ Tighten the bracket nuts to 42 Nm (37 ft. lbs.).
18. Install the glow plug relay power supply terminals.
19. Install the hold down nuts on the glow plug relay power supply terminals.
^ Tighten the terminal nuts to 4 Nm (44 inch lbs.).
20. Connect the glow plug relay electrical connector.
21. Install the Boost sensor gasket.
22. Install the Boost sensor.
23. Install the Boost sensor retaining bolts.
^ Tighten the terminal nuts to 3.5 Nm (27 inch lbs.).
24. Connect the Boost sensor electrical connector.
25. Install the IAT sensor.
^ Tighten the IAC sensor to 25 Nm (18 ft. lbs.).
26. Connect the Intake Air Temperature (IAT) sensor electrical connector.
27. Install the CDR valve.
28. Install the bracket for retaining the CDR valve to the right side lower intake manifold studs.
^ Tighten the bracket nuts to 23 Nm (17 ft. lbs.).
29. Instal the electrical harness and retaining brackets and nuts.
30. Install the nuts retaining the fuel pipe brackets,
^ Tighten the bracket nuts to 23 Nm (17 ft. lbs.).
31. Connect the gray engine harness electrical connector.
32. Install the upper radiator hose.
33. If equipped with rear Air Conditioning (A/C), install the rear A/C pipe to the A/C compressor.
34. Install new upper intake manifold gaskets to the lower intake manifolds.
Important: Always replace the O-ring between the upper intake manifold and the turbocharger.
35. Install a new O-ring onto the turbocharger inlet housing.
36. Lightly lubricate the O-ring with clean engine oil.
37. Install the upper intake manifold to the lower intake manifolds.
38. Install the upper intake manifold bolts
^ Tighten the upper intake manifold bolts to 23 Nm (17 ft. lbs.).
39. Install a small amount of RTV sealant GM P/N 12346286 to the area on the upper tube where it joins with the lower tube.
40. Install the upper oil level indicator tube.
41. Install the nut retaining the oil level indicator tube to the thermostat cross over.
^ Tighten the oil level indicator tube nut to 22 Nm (16 ft. lbs.).
42. Install the oil level indicator.
43. For the 6.5L diesel engine, install the bolt and the nut securing the oil level indicator tube brackets to the engine.
^ Tighten the bolt to 47 Nm (35 ft. lbs.).
^ Tighten the nut to 25 Nm (18 ft. lbs.).
44. Fill the engine coolant.
45. Recharge the A/C system, if required.
46. Install the air intake duct from the turbocharger.
47. Connect the battery negative cable from the battery.
48. Install the air cleaner assembly from the vehicle.
49. Install the engine cover from the vehicle.