FORD MUSTANG 2003 Workshop Manual

z
excessive connecting rod bearing clearance
Valve Train Analysis— Engine Off—Valve Cover Removed
Check for damaged or severely worn parts and correct assembly. Make sure correct parts are used
with the static engine analysis as follows.
Valve Train Analysis— Engine Off, Rocker Arm
z Check for loose mounting bolts, studs and nuts.
z Check for plugged oil feed in the rocker arms (6564) or cylinder head.
Valve Train Analysis— Engine Off, Camshaft Roller Followers and Hydraulic Lash Adjusters,
Overhead Camshaft
zCheck for loose mounting bolts on camshaft carriers.
z Check for plugged oil feed in the camshaft roller followers, lash adjusters or cylinder heads.
Valve Train Analysis— Engine Off, Camshaft— Engines
z Check for broken or damaged parts.
Valve Train Analysis— Engine Off, Push Rods
z Check for bent push rods (6565) and restricted oil passage.
Valve Train Analysis— Valve Springs
z Check for broken or damaged parts.
Valve Train Analysis— Engine Off, Valve Spring Retainer and Valve Spring Retainer Keys
z Check for correct seating of the valve spring retainer key (6518) on the valve stem and in valve
spring retainer (6514).
z Check for correct seating on the valve stem.
Valve Train Analysis— Engine Off, Valves and Cylinder Head
z Check for plugged oil drain back holes.
z Check for worn or damaged valve tips.
z Check for missing or damaged guide- mounted valve stem seal.
z Check collapsed valve tappet gap.
z Check installed valve spring height.
z Check for missing or worn valve spring seats.
z Check for plugged oil metering orifice in cylinder head oil reservoir (if equipped).
Static checks (engine off) are to be made on the engine prior to the dynamic procedure. Klj . 14 ba
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Valve Train Analysis—
Engine Running
z Start the engine and, while idling, check for correct operation of all parts. Check the following:
Valve Train Analysis— Engine Running, Valves and Cylinder Head
z Check for plugged oil drain back holes.
z Check for missing or damaged valve stem seals or guide mounted valve stem seals.
z Check for a plugged oil metering orifice in the cylinder head oil reservoir (4.6L engine only).
If insufficient oiling is suspected, check oil passages for blockage, then accelerate the engine to 1,200
rpm with the transmission in NEUTRAL and the engine at normal operating temperature. Oil should
spurt from the rocker arm oil holes such that valve tips and camshaft roller followers are well oiled.
With the valve covers (6582) off, some oil splash may overshoot camshaft roller followers.
Valve Train Analysis— Engine Running, Camshaft Lobe Lift— OHC Engines
Check the lift of each camshaft lobe in consecutive order and make a note of the readings. 1. Remove the valve covers.
2. Remove the spark plugs.
3. Install the Dial Indicator Gauge with Holding Fixture so the rounded tip of indicator is on top of the camshaft lobe and on the same plane as the valve tappet.
4. Rotate the crankshaft using a breaker bar and socket attached to the crankshaft pulley retainer bolt. Rotate the crankshaft until the base circle of the camshaft lobe is reached.
5. Zero the dial indicator. Continue to rotate the crankshaft until the (1) high- lift point of the
camshaft lobe is in the fully- raised position (highest indicator reading).
6. To check the accuracy of the original indicator reading, continue to rotate crankshaft until the (2) base circle is reached. The indicator reading should be zero. If zero reading is not obtained,
repeat Steps 1 through 6.
7. NOTE: If the lift on any lobe is below specified service limits, install a new camshaft, and new
camshaft roller followers.
Remove the Dial Indicator Gauge with Holding Fixture.
8. Install the spark plugs. Klj . 15 ba
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9. Install the valve covers.
Valve Train Analysis— Engine Running, Camshaft Lobe Lift— Push Rod Engine
Check the lift of each lobe in consecutive order and make a note of the readings. 1. Remove the valve covers.
2. Remove the rocker arm seat bolts, rocker arm seat (6A528) and rocker arms.
Typical Engine With Push Rods
3. Make sure the valve tappet is seated against camshaft (6250). Install (1) Dial Indicator Gauge with Holding Fixture so the ball socket adapter of the indicator is on top of the valve tappet or (2)
Dial Indicator Gauge Adapter is on top of push rod and in same plane as valve tappet push rod
movement.
4. Remove the spark plugs.
5. Connect an auxiliary starter switch in the starting circuit. Crank the engine with ignition switch in OFF position. Bump crankshaft over until valve tappet is on base circle of camshaft lobe. At this
point, valve tappet will be in its lowest position. If checking during engine assembly, turn
crankshaft using a socket or ratchet.
6. Zero the dial indicator. Continue to rotate crankshaft slowly until valve tappet is in fully- raised
position (highest indicator reading).
7. NOTE: If lift on any lobe is below specified service limits, install a new camshaft, and new valve
tappets.
Remove the Dial Indicator with Holding Fixture, Dial Indicator Gauge Adapter, and auxiliary
starter switch.
8. Install rocker arm seats, rocker arms and rocker arm seat bolts.
9. Install valve covers.
10. Install spark plugs.
Valve Train Analysis— Engine Running, Valve Tappet
Valve tappet noise can be caused by any of the following:
zexcessive valve tappet gap (collapsed) Klj . 16 ba
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z
incorrectly functioning valve tappet
z air in lubrication system
z excessive valve guide wear
z low oil pressure
Excessive collapsed valve tappet gap can be caused by loose rocker arm seat bolts/nuts, incorrect
initial adjustment or wear of valve tappet face, or worn roller valve tappets, push rod (6565), rocker
arm (6564), rocker arm seat or valve tip. With valve tappet collapsed, check gap between the valve tip
and the rocker arm to determine if any other valve train parts are damaged, worn or out of adjustment.
An incorrectly functioning valve tappet can be sticking, caused by contaminants or varnish inside the
tappet. The tappet can have a check valve that is not functioning correctly, which can be caused by an
obstruction, such as dirt or chips that prevent the check valve from closing, or a broken check valve
spring. A tappet with a leakdown time out of specification can cause tappet noise. If no other cause for
noisy valve tappets can be found, the leakdown rate should be checked and new valve tappets
installed if found to be out of specification.
Assembled valve tappets can be tested with Hydraulic Tappet Leakdown Tester to check the leakdown
rate. The leakdown rate specification is the time in seconds for the plunger to move a specified
distance while under a 22.7 kg (50 lb) load.
Air bubbles in the lubrication system will prevent the valve tappet from supporting the valve spring
load. This can be caused by too high or too low an oil level in the oil pan or by air being drawn into the
system through a hole, crack or leaking gasket on the oil pump screen cover and tube. Klj . 17 ba
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GENERAL PROCEDURES
Sprockets
1. WARNING: To avoid the possibility of personal injury or damage to the vehicle, do
not operate the engine with the hood open until the fan blade has been examined for
possible cracks and separation.
NOTE: Specifications show the expected minimum or maximum condition. Refer to the
appropriate section in Group 303 for the procedure.
NOTE: If a component fails to meet the specifications, it is necessary to install a new
component or refinish. If the component can be refinished, wear limits are provided as an aid to
making a decision. A new component must be installed for any component that fails to meet
specifications and cannot be refinished.
Inspect the timing chain/belt and the sprockets.
zInstall new components as necessary. Refer to the appropriate section in Group 303 for
the procedure.
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GENERAL PROCEDURES
Rocker Arms —
Cleaning
1. Clean all parts thoroughly. Make sure all oil passages are open.
2. Make sure oil passage in the push rod/valve tappet end of the rocker arm (6564) is open.
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GENERAL PROCEDURES
Rocker Arms —
Inspection
CAUTION: Do not attempt to true surfaces by grinding. Check the rocker arm pad, side
rails and seat for excessive wear, cracks, nicks or burrs. Check the rocker arm seat bolt for
stripped or broken threads. Install new components as ncessary or possible damage may
occur.
1. Inspect the rocker arm push rod bore for nicks, scratches, scores or scuffs. Install new components as necessary. Refer to the appropriate section in Group 303 for the procedure.
2. Inspect the pad at the valve end of the rocker arm for indications of scuffing or abnormal wear. If the pad is grooved, install a new rocker arm. Refer to the appropriate section in Group 303 for
the procedure.
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GENERAL PROCEDURES
Push Rods —
Cleaning
1. Clean the push rods (6565) in a suitable solvent. Blow out the oil passage in the push rods with compressed air.
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GENERAL PROCEDURES
Push Rods —
Inspection
1. CAUTION: Do not attempt to straighten push rods.
Check the ends of the push rods for nicks, grooves, roughness or excessive wear. Install new
push rods as necessary. Refer to the appropriate section in Group 303 for the procedure.
z The push rods can be checked for straightness while they are installed in the engine by
rotating them with the valve closed.
z They also can be checked using a Dial Indicator with Bracketry.
2. If the push rod is bent beyond specifications, install a new push rod. Refer to the appropriate section in Group 303 for the procedure.
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GENERAL PROCEDURES
Camshaft Journal —
Diameter
1. Measure each camshaft journal diameter in two directions. zIf out of specification, install new components as necessary. Refer to the appropriate
section in Group 303 for the procedure.
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