Intake Manifold: Service and Repair

1. Disconnect battery ground cable and drain engine cooling system.
2. Remove air cleaner assembly including air intake duct and heat tube.
3. Disconnect accelerator cable at throttle body assembly, then speed control cable, if equipped.
4. Disconnect transmission linkage at upper intake manifold.
5. Remove bolts from accelerator cable mounting bracket and position cables aside.
6. Disconnect fuel lines at injector fuel rail assembly.
7. Disconnect radiator hose at thermostat housing.
8. Disconnect the coolant bypass hose from manifold.
9. Remove heater tube as follows:
a. Disconnect heater tube from intake manifold.
b. Remove tube support bracket retaining nuts, then remove heater hose from rear of heater tube.
c. Loosen hose clamp at heater elbow, then remove heater tube with hose attached.
d. Remove heater tube with lines attached and set assembly aside.
10. Disconnect vacuum lines at fuel rail assembly and intake manifold, then disconnect necessary electrical connectors.
11. Remove A/C compressor support bracket, if equipped. Disconnect one PCV line from upper intake manifold and valve. Remove second PCV line from left rocker cover.
12. Remove throttle body assembly, then the EGR valve assembly from upper manifold.
13. Remove wiring retainer bracket from left front side of intake manifold and position aside with spark plug wires.
14. Remove upper intake manifold bolts and studs, then the upper intake manifold.
15. Remove injectors and fuel rail assembly.
16. Remove heater water outlet hose, then the lower intake manifold attaching bolts and studs.
17. Remove lower intake manifold.

NOTE: The manifold is sealed at each end with RTV-type sealer. To break seal, it may be necessary to pry on front of manifold with a screwdriver blade. Use care to prevent damage to machined surfaces when prying.

18. Remove and discard manifold side gaskets and end seals.
19. Reverse procedure to install, noting the following:
a. Clean all cylinder head/block to intake manifold contact areas.
b. Apply a dab of gasket and trim adhesive 19B508-AA, or equivalent to each cylinder head mating surface. Press new intake manifold gasket into place over locating dowels.
c. Apply a 1/8 inch bead of silicone sealer D6AZ-19562-B, or equivalent at each corner where cylinder head joins the cylinder block.
d. Install front and rear intake manifold end seals, then carefully lower intake manifold into position on cylinder block and cylinder heads. Use locating dowels as necessary to guide manifold.

Fig. 4 Intake Manifold Tightening Sequence:

e. Install attaching bolts and studs. Torque in two steps: first to 44 in lb, then to 71-106 in lb in sequence shown.