Exhaust Manifold - Exhaust Leak
88ford08EXHAUST - 4.9L - MANIFOLD WARPS AND
LEAKS
NOISE - 4.9L - EXHAUST MANIFOLD WARPS AND LEAKS
Article No.
88-7-16
LIGHT TRUCK: 1984-86 E SERIES, F SERIES, BRONCO
WARNING: This modification is authorized only for the listed engines. Performing this modification on other engine calibrations is unauthorized and could create liability under applicable federal or local laws.
ISSUE: A leak at the exhaust manifold may be caused by the exhaust manifold expanding more than normal and warping under certain operating conditions. The expanding and warping exhaust manifold causes the manifold retaining bolts to lose their torque which results in the leaking condition.
ACTION: To correct this, install a new design exhaust manifold kit that contains a warp resistent exhaust manifold made out of a high silicon cast iron and new steel hot box studs. On selected calibrations it will be necessary to install a new level EEC IV processor. Refer to the following service procedure.
1. Remove the air cleaner.
2. Disconnect the accelerator cable or accelerator rod at the carburetor and remove the accelerator return spring, if equipped.
3. Remove the kickdown rod return spring and kickdown rod bellcrank from vehicles equipped with automatic transmissions.
4. Disconnect the fuel line at the carburetor.
5. Label and then disconnect the vacuum lines from the carburetor and intake manifold.
6. Disconnect the carburetor feedback solenoid wiring at the carburetor.
7. Disconnect the electrical connector from the choke cap.
8. Remove the carburetor.
9. Disconnect the exhaust pipe from the exhaust manifold.
10. Disconnect the vacuum line for the brake booster, if equipped.
11. Remove the retaining bolts and nuts holding the intake and exhaust manifolds to the cylinder head.
12. Lift the intake manifold and exhaust manifolds as an assembly from the vehicle.
13. Remove the gasket from the cylinder head.
14. Remove the nuts holding the intake manifold and exhaust manifold together.
15. Obtain Exhaust Manifold Service Kit, E4TZ-9426-D.
16. Clean the intake manifold, exhaust manifold and cylinder head mating surfaces.
17. Check the manifold hot box mating surface for warping. If warped, the intake manifold must be replaced.
NOTE: To check the manifold hot box mating surface use an intake manifold that you are sure is not warped.
FIGURE 15:
18. Replace the choke tubes and choke control insert in the exhaust manifold, Figure 15.
19. Apply graphite grease, (C3AZ-19578-A) on the mating surfaces of the intake manifold and exhaust manifold.
FIGURE 16:
20. Assemble the intake manifold to the exhaust manifold. Use the new nuts, bolts and washers supplied in the kit. Do not torque the bolts at this time, Figure 16.
FIGURE 17:
21. Install the new intake manifold gasket supplied in the kit, Figure 17.
22. Apply graphite grease, (C3AZ-19578-A) on the mating surfaces of the exhaust manifold and cylinder head.
23. Carefully position the intake manifold to the cylinder head making sure not to move the intake manifold gasket out of place.
24. Install the new intake manifold washer clamps, bolts, nuts and studs supplied in the kit, Figure 17.
FIGURE 18:
25. Torque the bolts and nuts on the intake manifold and exhaust manifold to the cylinder head to 22-32 ft.lbs. (30-43 N-m) in the sequence shown in Figure 18.
CAUTION: The intake and exhaust manifold assembly must be torque to specification before the three (3) nuts and studs in the hot box are tightened.
26. Torque the nuts and bolts installed in Step 20 that attach the intake manifold to the exhaust manifold to 22-32 ft.lbs. (30-43 N-m).
27. Reconnect the brake booster vacuum line, if equipped.
28. Reinstall the carburetor.
29. Reconnect the exhaust pipe to the exhaust manifold.
30. Reconnect the carburetor feedback solenoid wiring.
31. Reconnect the electric choke cap connector.
32. Reconnect the vacuum lines to the carburetor and the intake manifold.
33. Reconnect the fuel inlet line to the carburetor.
34. Reconnect the kickdown rod return spring and kickdown rod bellcrank on vehicles equipped with automatic transmissions.
35. Reinstall the air cleaner.
36. On vehicle calibrations 4-52L R00, 4-52L-R10 for Econolines and 4-52G R00, 4-52G-R10 for F Series vehicles, install a new level EEC IV processor, E5DZ-12A650-UB.
37. Reset the initial timing to 10 degrees BTDC.
Obtain an Authorized Modification Decal and list the date, dealer number, and summary of alterations performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modification Decal. Clean the area, install the decal and cover it with a clear plastic decal shield.
PART NUMBER PART NAME CLASS
E4TZ-9426-D Exhaust Manifold Kit BG
E5DZ-12A650-UB EEC IV Processor RM
C3AZ-19578-A Graphite Grease AM
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Eligible Under Basic Warranty and Powertrain Warranty Coverages
OPERATION: 880716A - Steps 1 through 35
TIME: 2.8 Hrs. - F Series and Bronco 3.2 Hrs. - Econoline
OPERATION: 880716A1 - Extra time to install new intake manifold
TIME: 0.4 Hr. - All
OPERATION: 880716B - Steps 36 and 37
TIME: 0.5 Hr. - All
DLR. CODING: Basic Part No. 9430
Condition Code: 24