1991 1999 ford explorer chilton User Manual

							Refill and bleed the cooling system.
23. 
Connect the negative battery cable, start the engine and check for leaks.
24. 
Cylinder Head
REMOVAL & INSTALLATION
Before installing the cylinder heads, have them cleaned and professionally checked. If there is a
problem, generally, it will not go away by simply installing new gaskets. Cylinder heads can and do
warp, which is the major cause of gasket failure. This is usually due to overheating.
2.3L and 2.5L Engine Disconnect the negative battery cable.
1. 
Drain cooling system.
2. 
CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are
quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove
fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless
it is contaminated or several years old.
Remove air cleaner assembly.
3. 
Remove the heater hose-to-valve cover retaining screws.
4. 
Remove the spark plugs.
5. 
Label and disconnect all of the upper engine components and alternator wiring harnesses.
6. 
Label and remove the spark plug wires.
7. 
Disconnect the Exhaust Gas Oxygen (EGO) sensor at the exhaust manifold.
8. 
Disconnect required vacuum hoses.
9. 
Remove dipstick tube and bracket.
10. 
Remove rocker retaining bolts and remove cover.
11. 
Remove intake manifold retaining bolts.
12. 
Loosen alternator retaining bolts and remove belt from the pulley. Remove mounting bracket
retaining bolts to the head.
13. 
Disconnect the upper radiator hose at both ends and remove from the vehicle.
14. 
Remove the timing belt cover bolts and remove the cover. For power steering-equipped vehicles,
unbolt the power steering pump bracket and position it off to the side.
15. 
Loosen the timing belt idler retaining bolts. Position idler in the unloaded position and tighten the
retaining bolts.
16. 
Remove the timing belt from the cam pulley and auxiliary pulley.
17. 
Remove four nuts and/or stud bolts retaining heat stove to exhaust manifold.
18. 
Remove the eight exhaust manifold retaining bolts.
19. 
Remove the timing belt idler and two bracket bolts.
20. 
Remove the timing belt idler spring stop from the cylinder head.
21. 
Disconnect the oil sending unit lead wire.
22. 
Remove the cylinder head retaining bolts.
23. 
Remove the cylinder head.
24. 
Clean the cylinder head, intake manifold and exhaust manifold gasket surfaces.
25. 
Blow oil out of the cylinder head bolt block hoses.
26. 
Clean valve cover gasket surface on the head.
27. 
Check cylinder head for flatness.
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334 Cylinder Head 
						

							
To install:
Position head gasket on the block.
29. 
Clean rocker arm cover (cam cover).
30. 
Install valve cover gasket to the valve cover.
31. 
Position cylinder head to block.
32. 
Install cylinder head retaining bolts and tighten to specifications.
33. 
Fig. 1: 2.3L and 2.5L cylinder head bolt tightening sequence Click to enlarge
Connect oil sending unit lead wires.
34. 
Install the timing belt idler spring stop to the cylinder head.
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REMOVAL & INSTALLATION 335 
						

							Position the timing belt idler to the cylinder head, and install its retaining bolts.
36. 
Install the eight exhaust manifold retaining bolts and/or stud bolts.
37. 
Install four nuts and/or stud bolts retaining heat stove to exhaust manifold.
38. 
Align the cam gear with pointer.
39. 
Align the crank pulley (TDC) with the pointer on the timing belt cover.
40. 
Position the timing belt to the pulleys (cam and auxiliary).
41. 
Loosen idler retaining bolts to tension the belt, then rotate the engine and check timing alignment.
42. 
Adjust belt tensioner and tighten retaining bolts.
43. 
Install the timing belt cover and its four retaining bolts.
44. 
Connect the upper radiator hose to the engine and radiator and tighten the retaining clamps.
45. 
Position the alternator bracket to cylinder head and install its retainers.
46. 
If removed, position the power steering pump bracket to the engine and install its attaching bolts.
47. 
Install the accessory drive belt and, if necessary, adjust the belt tension using Belt Tension Gauge
Rotunda 021-00045 or equivalent.
48. 
Position the intake manifold to the cylinder head, and install its retaining bolts.
49. 
Install the rocker arm covers and retaining bolts.
50. 
Install the spark plugs.
51. 
Install the dipstick tube and bracket.
52. 
Connect the appropriate vacuum hoses.
53. 
Connect all of the upper engine components and alternator wiring harnesses.
54. 
Position and connect the spark plug wires.
55. 
Install the heater hose-to-valve cover retaining screws.
56. 
Fill and bleed the cooling system.
57. 
Install the air cleaner.
58. 
Connect the negative battery cable.
59. 
Start the engine and check for leaks.
60. 
2.9L Engines
According to the manufacturer, you must use new cylinder head bolts when installing the heads. Disconnect the battery ground cable.
1. 
Drain the radiator coolant.
2. 
CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are
quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove
fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless
it is contaminated or several years old.
Remove the intake tube from the throttle body and disconnect the throttle linkage and cover.
3. 
Remove the distributor.
4. 
Remove the radiator hose and the by-pass hose from the thermostat housing and intake manifold.
5. 
Remove the rocker arm covers and the rocker arm shafts.
6. 
Depressurize the fuel system and remove the fuel line from the fuel rail.
7. 
Remove the intake manifold.
8. 
Remove and label the pushrods in order to keep them in sequence for proper assembly.
9. 
Remove the exhaust manifolds.
10. 
Remove the cylinder head attaching bolts. Remove the cylinder heads and discard the head gaskets.
11. 
To install: Clean the cylinder heads, intake manifold, valve rocker arm cover and cylinder block gasket surfaces.
12. 
Place the cylinder head gaskets in position on the cylinder block.
13.  HOW TO USE THIS BOOK
336 REMOVAL & INSTALLATION 
						

							
Gaskets are marked with the words FRONT and TOP for correct positioning. Left and right cylinder
head gaskets are not interchangeable. Use new cylinder head bolts.
Cylinder head alignment studs on the 2.9L engineClick to enlarge
Cylinder head torque sequence for the 2.9L engine
Install the fabricated alignment dowels in the cylinder block and install the cylinder head assemblies
on the cylinder block, one at a time.
14. 
Remove the alignment dowels and install new cylinder head attaching bolts. Tighten the bolts to
specification following the torque sequence.
15. 
Install the intake manifold.
16. 
Install the exhaust manifolds.
17. 
Apply Lubriplate®, or equivalent, to both ends of the pushrods and install the pushrods.
18. 
Install oil baffles and rocker arms.
19. 
Install the distributor.
20. 
Adjust the valves as described in Section 1 under Valve Lash adjustment.
21. 
Install the rocker arm covers.
22. 
Connect the fuel line to the fuel rail.
23. 
Install the distributor cap with spark plug wires attached. Coat the inside of each spark plug boot with
silicone lubricant and install them on the spark plug.
24. 
Install the throttle linkage and air cleaner intake tube.
25. 
Fill the cooling system according to instructions on the underhood decal and bleed the cooling system.
26. 
Connect the battery ground cable.
27. 
Operate the engine at fast idle and check for oil, fuel and coolant leaks.
28. 
If necessary, check and adjust the ignition timing.
29. 
3.0L Engine
According to the manufacturer, you must use new cylinder head bolts when installing the heads. Drain the cooling system (engine cold) into a clean container and save the coolant for reuse.
1.  HOW TO USE THIS BOOK
REMOVAL & INSTALLATION 337 
						

							CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are
quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove
fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless
it is contaminated or several years old.
Disconnect the battery ground cable.
2. 
Remove the air cleaner.
3. 
Relieve fuel pressure. Disconnect fuel lines as necessary. Mark vacuum line location and remove
lines.
4. 
Disconnect upper and lower radiator hoses-position out of the way.
5. 
Label and remove the ignition wires from the spark plugs and locating studs.
6. 
If equipped, mark the distributor housing to block and note rotor position. Remove the distributor.
7. 
Remove coil assembly.
8. 
Remove the throttle body. See Section 5.
9. 
Remove the accessory drive belt.
10. 
If the left-hand cylinder head is being removed: Remove the power steering pump and bracket assembly. DO NOT disconnect the hoses. Tie
the assembly out of the way.
1. 
Remove the engine oil dipstick and tube. Rotate or remove tube assembly.
2. 
Remove the fuel line retaining bracket bolt from the front of cylinder head.
3. 
11. 
If the right-hand head is being removed: Disconnect alternator electrical harnesses.
1. 
Remove belt tensioner assembly.
2. 
Remove the alternator and bracket.
3. 
Remove hose from valve cover to oil fill adapter.
4. 
12. 
Remove the spark plugs.
13. 
Remove the exhaust manifold(s).
14. 
Remove the rocker arm covers as previously described.
15. 
Loosen rocker arm fulcrum retaining bolts enough to allow the rocker arm to be lifted off the pushrod
and rotate to one side.
16. 
Regardless of which cylinder head is being removed, the #3 cylinder intake valve pushrod must be
removed to allow removal of the intake manifold.
Remove the pushrods, keeping them in order so they may be installed in their original locations.
17. 
Remove the intake manifold as outlined. Refer to the necessary service procedure.
18. 
Loosen the cylinder head attaching bolts in reverse of the torque sequence, then remove the bolts and
lift off the cylinder head(s). Remove and discard the old cylinder head gasket(s).
19. 
To install: Clean the cylinder heads, intake manifold, valve rocker arm cover and cylinder block gasket surfaces
of all traces of old gasket material and/or sealer.
20. 
Lightly oil all bolt and stud bolt threads except those specifying special sealant. Position the new head
gasket(s) on the cylinder block, using the dowels for alignment. The dowels should be replaced if
damaged.
21.  HOW TO USE THIS BOOK
338 REMOVAL & INSTALLATION 
						

							Cylinder head gasket positioning for the 3.0L
Click to enlarge
HOW TO USE THIS BOOK
REMOVAL & INSTALLATION 339 
						

							Cylinder head installation & bolt torque sequence for the 3.0L
Click to enlarge
HOW TO USE THIS BOOK
340 REMOVAL & INSTALLATION 
						

							Valve rocker arm installation procedure and collapsed lifter gap clearance check for the 3.0L
engine
Click to enlarge
Position the cylinder head(s) on the block and install new attaching bolts. Tighten the head bolts in
sequence to 5 ft. lbs. Back off all bolts one full turn (36 degrees). Retighten the cylinder head bolts in
sequence, in two steps to 37 ft. lbs. Final tighten to 11 ft. lbs.
22. 
Install intake manifold as outlined.
23. 
Dip each pushrod in heavy engine oil then install the pushrods in their original locations.
24. 
For each valve, rotate the crankshaft until the tappet rests on the heel (base circle) of the camshaft
lobe before tightening the fulcrum attaching bolts. Position the rocker arms over the pushrods. Install
the fulcrums (tighten to 8 ft. lbs. to seat fulcrum) and then tighten the fulcrum attaching bolts to 24 ft.
lbs. (32 Nm). Refer to the necessary illustration for details if necessary.
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REMOVAL & INSTALLATION 341 
						

							WARNING
The fulcrums must be fully seated in the cylinder head and pushrods must be seated in the rocker arm sockets
prior to final tightening.
Lubricate all rocker arm assemblies with heavy engine oil. If the original valve train components are
being installed, a valve clearance check is not required. If, however, a component has been replaced,
the valve clearance should be checked.
26. 
Install the exhaust manifold(s).
27. 
Install the dipstick tube and spark plugs.
28. 
Position the rocker arm cover with a new gasket on the cylinder head and install the retaining bolts.
Note the location of the spark plug wire routing clip stud bolts.
29. 
Install the injector harness.
30. 
If equipped, install the distributor.
31. 
Install the ignition coil assembly.
32. 
Install the spark plug wires.
33. 
Install the throttle body and new gasket. Refer to the necessary service procedures.
34. 
If the left hand cylinder head was removed, perform the following: Install the fuel line retaining bracket bolt to the front of cylinder head. Torque to 26 ft. lbs.
1. 
Install the engine oil dipstick and tube assembly.
2. 
Install the power steering pump and bracket assembly.
3. 
35. 
If the right hand cylinder head was removed, perform the following: Install hose from valve cover to oil fill adapter.
1. 
Install the alternator and bracket.
2. 
Install belt tensioner assembly.
3. 
Reconnect alternator electrical harnesses.
4. 
36. 
Install the accessory drive belt.
37. 
Connect fuel lines. Install fuel line safety clips.
38. 
Install all radiator hoses. Connect vacuum lines.
39. 
Drain and change engine oil.
40. 
CAUTION
The EPA warns that prolonged contact with used engine oil may cause a number of skin disorders, including
cancer! You should make every effort to minimize your exposure to used engine oil. Protective gloves should
be worn when changing the oil. Wash your hands and any other exposed skin areas as soon as possible after
exposure to used engine oil. Soap and water, or waterless hand cleaner should be used.
Install the air cleaner.
41. 
Fill and bleed the cooling system.
42. 
Connect the battery ground cable.
43. 
Start the engine and check for leaks. If equipped with distributor ignition, verify base ignition timing.
44. 
4.0L Engine (VIN X) Drain the cooling system (engine cold) into a clean container and save the coolant for reuse.
1. 
CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are
quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove
fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless
it is contaminated or several years old.
Disconnect the battery ground cable.
2. 
Remove the air cleaner.
3. 
Remove the rocker arm covers as previously described.
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342 REMOVAL & INSTALLATION 
						

							Remove the upper and lower intake manifolds as described earlier.
5. 
If the left cylinder head is being removed: Remove the accessory drive belt.
1. 
Remove the air conditioning compressor.
2. 
Remove the power steering pump and bracket assembly. DO NOT disconnect the hoses. Tie
the assembly out of the way.
3. 
Remove the spark plugs.
After removing the intake manifold, loosen the accessory mounting bracket bolts ...
... then remove the bracket and accessory
4. 
6. 
If the right head is being removed: Remove the accessory drive belt.
1. 
Remove the alternator and bracket.
2. 
Remove the EDIS ignition coil and bracket.
3. 
Remove the spark plugs.
4. 
7. 
Remove the exhaust manifold(s).
8.  HOW TO USE THIS BOOK
REMOVAL & INSTALLATION 343