Intake Manifold: Service and Repair

Remove or Disconnect
1. Negative battery cable.
2. Drain coolant to appropriate level.
3. Vacuum hose and electrical connector from MAP sensor.
4. Electrical connectors from:
^ MAP sensor.
^ Intake Air Temperature (IAT) sensor.
^ Purge solenoid.
^ Fuel injector harness. Position the harness aside.

5. Vacuum hoses from the intake manifold and hose at fuel regulator and purge solenoid to canister.
6. Throttle body to air cleaner duct.
7. Vent tube to air cleaner duct.
8. Throttle cable bracket.
9. Power brake vacuum line (including retaining bracket to power steering bracket) and position aside.
10. Oil/air separator (crankcase ventilation system). Leave the hoses attached to the separator. Disconnect hoses from the oil fill, chain cover, intake duct and the intake manifold. Remove as an assembly.
11. Oil/air separator hose from oil fill tube.
12. Oil fill cap and oil level indicator assembly.
13. Oil fill tube bolt/screw.
14. Pull oil fill tube upward to unseat from block.
15. Injector harness connector.
16. Remove fill tube out top, rotating as necessary to gain clearance for oil/air separator nipple between intake tubes and fuel rail electrical harness.
17. Intake manifold support brace.
18. Manifold retaining nuts and bolts.
19. Manifold and gasket.
^ Hole closest to chain housing is slotted for additional clearance.

Install or Connect
1. Manifold and new gasket.
^ Install new gasket with number stamp on gasket faced toward manifold surface.

2. Following tightening sequence, tighten bolts/nuts to 25 N.m (18 lbs. ft.).
3. Intake manifold brace and retainers.
4. Lubricate a new oil fill tube "0" ring seal with engine oil and install tube down between intake manifold. Rotate as necessary to gain clearance for oil/air separator nipple on fill tube.
5. Locate the oil fill tube in its cylinder block opening. Align the fill tube so it is approximately in its installed position. Place the palm of your hand over the oil fill opening and press straight down to seat fill tube and "0" ring into cylinder block.
6. Oil/air separator hose from oil fill tube (lubricate as necessary for hose installation).
7. Oil/air separator assembly (it may be necessary to lubricate the hoses for ease of assembly).
8. Oil fill tube bolt/screw.
9. Throttle body to intake manifold using a new gasket.
10. Power brake vacuum hose to throttle body and secure pipe to power steering bracket.
11. Throttle cable bracket.
12. Vacuum hoses to intake manifold and hose at fuel regulator and purge solenoid to canister.
13. Electrical connections to:
^ MAP sensor.
^ IAT sensor. If sensor is removed, apply sealant GM P/N 9985490 or equivalent to threads before installation.
^ Purge solenoid.
^ Fuel injector harness.

14. Coolant recovery tank.
15. Fill coolant tank.
16. Negative battery cable.
Inspect
^ Coolant level.
^ For leaks