Lower

1. Drain engine cooling system.
2. Remove upper intake manifold.
3. Remove fuel injector and fuel injection supply manifold.
4. Remove heater water outlet hose.
5. Remove lower intake manifold bolts/studs, then lower intake manifold.

NOTE: Intake manifold is sealed at each end with RTV-type sealer. To break seal, it may be necessary to pry on front of manifold with screwdriver blade. If it is necessary to pry on intake manifold, use care to prevent damage to machined surfaces.

6. Remove and discard intake manifold gasket and end seals.
7. If lower intake manifold is to be disassembled, proceed as follows:
a. Remove water outlet connection and water thermostat, then engine coolant temperature sensor. Water bypass tube is pressed-in and is not serviceable.
b. Remove heater elbow.
c. Remove all vacuum and electrical fittings.
8. Reverse procedure to install, noting following:
a. Lightly oil all bolt and stud threads before installation.
b. When using silicone rubber sealer, assembly must occur within 15 minutes after sealer application. After this time, sealer may start to set and its effectiveness may be reduced.
c. Ensure lower intake manifold, cylinder head and cylinder block mating surfaces are clean and free of old gasketing material. Clean with suitable solvent.
d. If intake manifold was disassembled, apply coat of pipe sealant with Teflon(r) part No. D8AZ-19554-A or equivalent, to all vacuum fittings, heater elbows and electrical fittings.
e. Install lower intake manifold bolts and stud bolt in original locations.

Lower Intake Manifold Bolt Tightening Sequence:

f. Torque lower intake manifold bolts and stud bolt in sequence, to 8 ft lb, then to 15 ft lb.
g. Fill engine cooling system, then start engine and check for leaks.