Ford 2003 Mustang Workshop Manual page 853

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:
excessive valve tappet gap (collapsed)