vacuum FORD MUSTANG 2003 Owner's Manual

DIAGNOSIS AND TESTING
Engine
SECTION 303-
00: Engine System — General Information 2003 Mustang Workshop Manual Special Tool(s)
Commercially Available
Leakdown Tester
—
Quick Disconnect Compression
Tester
134-
R0212 or equivalent Dial Indicator Gauge Adapter
303-
007 (TOOL- 6565-AB) or
equivalent Dial Indicator Gauge with
Holding Fixture
100-
002 (TOOL- 4201-C) or
equivalent Engine Cylinder Leak
Detection/Air Pressurization Kit
014-00708 or equivalent
Oil Pressure Gauge
303-
088 (T73L-6600- A) UV Leak Detector Kit
164-
R0756 or equivalent Vacuum/Pressure Tester
164-
R0253 or equivalent Klj . 1 ba
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REFER to the Powertrain
Control/Emissions Diagnosis
(PC/ED) manual.
z Damaged charging
system/battery. z
REFER to Section 414 - 00 .
z Burnt valve. zINSTALL a new valve.
z Worn piston. zINSTALL a new piston.
z Worn piston rings. zINSTALL new piston rings.
z Worn cylinder. zREPAIR or INSTALL a new
cylinder block.
z Damaged head
gasket. z
INSTALL a new head gasket.
z Damaged cooling
system. z
Refer to the appropriate section
in Group 303 for the procedure.
REFER to the Powertrain
Control/Emissions Diagnosis
(PC/ED) manual.
z Poor idling zVacuum leaks. zRefer to the appropriate section
in Group 303 for the procedure.
REFER to the Powertrain
Control/Emissions Diagnosis
(PC/ED) manual.
z Malfunctioning or
damaged ignition
system. z
Refer to the appropriate section
in Group 303 for the procedure.
REFER to the Powertrain
Control/Emissions Diagnosis
(PC/ED) manual.
z Malfunctioning or
damaged fuel
system. z
Refer to the appropriate section
in Group 303 for the procedure.
REFER to the Powertrain
Control/Emissions Diagnosis
(PC/ED) manual.
z Damaged valve
tappet or lash
adjuster. z
INSTALL a new valve tappet or
lash adjuster.
z Damaged valve
tappet guide or lash
adjuster. z
INSTALL a new valve tappet
guide or valve tappet.
z Incorrect valve-to-
valve seat contact. z
REPAIR or INSTALL a new
valve or valve seat.
z Damaged head
gasket. z
INSTALL a new head gasket.
z Abnormal
combustion z
Malfunctioning or
damaged fuel
system. z
Refer to the appropriate section
in Group 303 for the procedure.
REFER to the Powertrain
Control/Emissions Diagnosis
(PC/ED) manual.
z Malfunctioning or
damaged ignition
system. z
Refer to the appropriate section
in Group 303 for the procedure.
REFER to the Powertrain
Control/Emissions Diagnosis
(PC/ED) manual.
z Malfunctioning or
damaged air intake
system. z
Refer to the appropriate section
in Group 303 for the procedure.
REFER to the Powertrain
Control/Emissions Diagnosis Klj . 3 ba
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Intake Manifold Vacuum Test
Bring the engine to normal operating temperature. Connect the Vacuum/Pressure Tester to the intake
manifold. Run the engine at the specified idle speed.
The vacuum gauge should read between 51-
74 kPa (15-22 in-Hg) depending upon the engine
condition and the altitude at which the test is performed. Subtract 4.0193 kPa (1 in- Hg) from the
specified reading for every 304.8 m (1,000 feet) of elevation above sea level.
The reading should be steady. If necessary, adjust the gauge damper control (where used) if the
needle is fluttering rapidly. Adjust the damper until the needle moves easily without excessive flutter.
Intake Manifold Vacuum Test—Interpreting Vacuum Gauge Readings
A careful study of the vacuum gauge reading while the engine is idling will help pinpoint trouble areas.
Always conduct other appropriate tests before arriving at a final diagnostic decision. Vacuum gauge
readings, although helpful, must be interpreted carefully.
Most vacuum gauges have a normal band indicated on the gauge face.
The following are potential gauge readings. Some are normal; others should be investigated further.
1. NORMAL READING: Needle between 51- 74 kPa (15-22 in-Hg) and holding steady.
2. NORMAL READING DURING RAPID ACCELERATION AND DECELERATION: When the engine is rapidly accelerated (dotted needle), the needle will drop to a low reading (not to zero).
When the throttle is suddenly released, the needle will snap back up to a higher than normal
figure.
3. NORMAL FOR HIGH- LIFT CAMSHAFT WITH LARGE OVERLAP: The needle will register as low as 51 kPa (15 in - Hg) but will be relatively steady. Some oscillation is normal. Klj . 11 ba
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4. WORN RINGS OR DILUTED OIL: When the engine is accelerated (dotted needle), the needle
drops to 0 kPa (0 in- Hg). Upon deceleration, the needle runs slightly above 74 kPa (22 in- Hg).
5. STICKING VALVES: When the needle (dotted) remains steady at a normal vacuum but occasionally flicks (sharp, fast movement) down and back about 13 kPa (4 in- Hg), one or more
valves may be sticking.
6. BURNED OR WARPED VALVES: A regular, evenly- spaced, downscale flicking of the needle
indicates one or more burned or warped valves. Insufficient hydraulic lash adjuster or hydraulic
lash adjuster (HLA) clearance will also cause this reaction.
7. POOR VALVE SEATING: A small but regular downscale flicking can mean one or more valves are not seating.
8. WORN VALVE GUIDES: When the needle oscillates over about a 13 kPa (4 in- Hg) range at idle
speed, the valve guides could be worn. As engine speed increases, the needle will become
steady if guides are responsible.
9. WEAK VALVE SPRINGS: When the needle oscillation becomes more violent as engine rpm is increased, weak valve springs are indicated. The reading at idle could be relatively steady.
10. LATE VALVE TIMING: A steady but low reading could be caused by late valve timing.
11. IGNITION TIMING RETARDING: Retarded ignition timing will produce a steady but somewhat low reading.
12. INSUFFICIENT SPARK PLUG GAP: When spark plugs are gapped too close, a regular, small pulsation of the needle can occur.
13. INTAKE LEAK: A low, steady reading can be caused by an intake manifold or throttle body gasket leak.
14. BLOWN HEAD GASKET: A regular drop of fair magnitude can be caused by a blown head gasket or warped cylinder head- to-cylinder block surface.
15. RESTRICTED EXHAUST SYSTEM: When the engine is first started and is idled, the reading may be normal, but as the engine rpm is increased, the back pressure caused by a clogged
muffler (5230), kinked tail pipe or other concerns will cause the needle to slowly drop to 0 kPa
(0 in-Hg). The needle then may slowly rise. Excessive exhaust clogging will cause the needle to
drop to a low point even if the engine is only idling.
16. When vacuum leaks are indicated, search out and correct the cause. Excess air leaking into the system will upset the fuel mixture and cause concerns such as rough idle, missing on
acceleration or burned valves. If the leak exists in an accessory unit such as the power brake
booster (2005), the unit will not function correctly. Always fix vacuum leaks.
Excessive Engine Oil Consumption
The amount of oil an engine uses will vary with the way the vehicle is driven in addition to normal
engine- to-engine variation. This is especially true during the first 16,100 km (10,000 miles) when a new
engine is being broken in or until certain internal engine components become conditioned. Vehicles
used in heavy- duty operation may use more oil. The following are examples of heavy- duty operation:
z trailer towing applications
z severe loading applications
z sustained high speed operation Klj . 12 ba
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Item Part Number Description
1 9F797 Engine wire harness
2 9E926 Throttle body
3 9F670 Idle air control gasket
4 9F715 Idle air control valve
5 9E498 Emissions vacuum harness
6 9424 Intake manifold (upper)
7 9H486 Intake manifold gasket (upper)
8 12029 Ignition coil Klj . 4 ba
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Cylinder Block and Lower End Components 9 18801 Radio ignition interference capacitor
10 12281 Ignition wire set —
LH 11 18696 Tube assembly
12 9424 Intake manifold (lower)
13 9439 Intake manifold gasket —
RH 14 9439 Intake manifold gasket —
LH 15 9A424 Intake manifold seal (rear)
16 6A008 Cylinder head-
to-block dowel 17 6010 Cylinder block
18 6A373 Engine rear plate (automatic transmission)
19 6375 Flywheel (automatic transmission)
20 6375 Flywheel (manual transmission)
21 6A372 Engine rear plate (manual transmission)
22 6723 Oil pan rear seal
23 6675 Oil pan
24 7120 Pilot bushing
25 9278 Oil pressure sensor
26 9B339 Oil pressure sensor fitting
27 9A424 Intake manifold seal (front)
28 18663 Heater water outlet tube
29 8255 Thermostat housing-
to-intake manifold gasket 30 8592 Water outlet connection
31 9875 Water thermostat
32 9D475 EGR valve
33 9H465 Vacuum control solenoid
34 9723 Accelerator cable bracket
35 9E936 Throttle body gasket
36 9J433 EGR transducer
37 9E498 Vacuum hose
38 12280 Ignition wire set —
RH Klj . 5 ba
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IN-
VEHICLE REPAIR
Upper Intake Manifold
Removal 1. Disconnect the battery ground cable. For additional information, refer to Section 414 - 01 .
2. Remove the engine air cleaner outlet pipe. For additional information, refer to Section 303 - 12 .
3. Disconnect the vacuum hose and the idle air control (IAC) valve electrical connector.
4. Disconnect the throttle position (TP) sensor electrical connector and the evaporative emissions (EVAP) return tube.
5. Disconnect the accelerator and the speed control cables from the throttle body cam. 6. Remove the bolts and position the accelerator cable bracket assembly aside. SECTION 303-
01A: Engine — 3.8L 2003 Mustang Workshop Manual Klj . 1 ba
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7. Disconnect the differential pressure feedback exhaust gas recirculation (EGR) system electrical
and vacuum connections.
8. Disconnect the EGR vacuum regulator solenoid electrical and vacuum connections.
9. Disconnect the positive crankcase ventilation (PCV) tube. 10. Disconnect the vacuum hoses. Klj . 2 ba
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11. Disconnect the following:
zIgnition coil electrical connector.
z Radio interference capacitor electrical connector.
z Spark plug wires.
12. Disconnect the vacuum hose.
13. NOTE: For ease in installation, record the location of the long bolts and the short bolts.
Remove the upper intake manifold. 1. Remove the 12 bolts.
2. Remove the upper intake manifold. Klj . 3 ba
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z
Stage 1: Tighten to 10 Nm (89 lb- in).
z Stage 2: Rotate an additional 90 degrees (1/4 turn).
3. Connect the vacuum hose.
4. Connect the following: zIgnition coil electrical connector.
z Radio interference capacitor electrical connector.
z Spark plug wires. Klj . 5 ba
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