2003 FORD MUSTANG towing

1. If compression improves considerably, piston rings are faulty.
2. If compression does not improve, valves are sticking or seating incorrectly.
3. If two adjacent cylinders indicate low compression pressures and squirting oil on each piston
does not increase compression, the head gasket may be leaking between cylinders. Engine oil
or coolant in cylinders could result from this condition.
Use the Compression Pressure Limit Chart when checking cylinder compression so that the
lowest reading is within 75 percent of the highest reading.
Cylinder Leakage Detection
When a cylinder produces a low reading, use of the Engine Cylinder Leak Detection/Air Pressurization
Kit will be helpful in pinpointing the exact cause.
The leakage detector is inserted in the spark plug hole, the piston is brought up to dead center on the
compression stroke, and compressed air is admitted.
Once the combustion chamber is pressurized, a special gauge included in the kit will read the
percentage of leakage. Leakage exceeding 20 percent is excessive.
While the air pressure is retained in the cylinder, listen for the hiss of escaping air. A leak at the intake
valve (6507) will be heard in the throttle body (9E926). A leak at the exhaust valve (6505) can be
heard at the tail pipe. Leakage past the piston rings will be audible at the positive crankcase ventilation
(PCV) connection. If air is passing through a blown head gasket to an adjacent cylinder, the noise will
be evident at the spark plug hole of the cylinder into which the air is leaking. Cracks in the cylinder
block or gasket leakage into the cooling system may be detected by a stream of bubbles in the radiator
(8005).
Oil Consumption Test
The following diagnostic procedure is used to determine the source of excessive internal oil
consumption. 1. NOTE: Oil use is normally greater during the first 16,100 km (10,000 miles) of service. As
mileage increases, oil use generally decreases. Vehicles in normal service should get at least
1,450 km per liter (900 miles per quart) after 16,000 km (10,000 miles) of service. High speed
driving, towing, high ambient temperature and other factors may result in greater oil use.
Define excessive oil consumption, such as the number of miles driven per liter (quart) of oil
used. Also determine customer's driving habits, such as sustained high speed operation,
towing, extended idle and other considerations.
2. Verify that the engine has no external oil leak as described under Engine Oil Leaks in the Diagnosis and Testing portion of this section.
3. Verify that the engine has the correct oil level dipstick (6750).
4. Verify that the engine is not being run in an overfilled condition. Check the oil level at least five minutes after a hot shutdown with the vehicle parked on a level surface. In no case should the
level be above MAX or the letter F in FULL. If significantly overfilled, carry out Steps 6a through
6d.
5. Verify the spark plugs are not oil saturated. If the spark plugs are oil saturated and compression is good it can be assumed the valve seals or valve guides are at fault. Klj . 9 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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DIAGNOSIS AND TESTING
Transmission Cooling
Inspection and Verification
WARNING: Never remove the radiator cap under any conditions while the engine is
operating. Failure to follow these instructions could result in personal injury and/or damage to
the cooling system or engine. To avoid having scalding hot coolant or steam blow out of the
radiator, use extreme care when removing the radiator cap from a hot radiator. Wait until the
engine has cooled, then wrap a thick cloth around the radiator cap and turn it slowly to the first
stop. Step back while the pressure is released from the cooling system. When you are certain
all the pressure has been released, press down on the radiator cap (with a cloth), turn and
remove.
The transmission fluid cooler is integral to the radiator (8005). Whenever leaks or damage to the
radiator are found, install an entire new radiator. For additional information, refer to Section 303 - 03A or
Section 303 - 03B .
Symptom Chart SECTION 307-
02: Transaxle/Transmission Cooling 2003 Mustang Workshop Manual SYMPTOM CHART
Condition
Possible Sources Action
z Transmission
Overheating z
Damaged radiator. zREPAIR or install a new
radiator. For additional
information, REFER to
Section 303 - 03A or
Section 303 - 03B .
z System leaks. zINSPECT for leaks. REPAIR
as necessary.
z Incorrect fluid level. zADJUST to proper level.
z Fluid condition. zINSPECT according to
instructions under Fluid
Condition Check. REFER to
Section 307 - 01 .
z Damaged, blocked,
reversed, leaking or
restricted cooler lines
or cooler tubes. z
INSPECT cooler lines and
tubes. REPAIR or flush as
necessary.
z Engine concerns
causing transmission
to overheat. z
INSPECT engine cooling
system. For additional
information, REFER to
Section 303 - 03A or
Section 303 - 03B .
z Excessive towing
loads. z
CHECK gross vehicle weight.
z Incorrect idle or
performance. z
REFER to the Powertrain
Control/Emissions Diagnosis
(PC/ED) manual. Klj . 1 ba
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z
Other
component
leaking. z
IDENTIFY leaking fluid
as engine, power
steering, or transmission
fluid. REPAIR as
necessary.
z False report. zREMOVE all traces of
lube on the exposed
transmission surfaces.
CHECK the vent for free
breathing. OPERATE
the transmission and
INSPECT for new
leakage. REPAIR as
necessary. REFER to
Section 308 - 03A or
Section 308 - 03B .
z Internal
components. z
INSPECT for leaks at
the input shaft bearing
retainer seal and the
shift rail expansion plug.
REFER to Section 308 -
03A or
Section 308 -
03B . INSPECT for leaks
at the top cover gasket.
INSPECT the case for
sand holes or cracks.
REPAIR or INSTALL a
new case as necessary.
REFER to Section 308 -
03A or
Section 308 -
03B .
z Fill and drain
plugs. z
CHECK fill and drain
plugs and bore threads.
REPAIR as necessary.
TIGHTEN plugs to
specified torque value.
REFER to Section 308 -
03A or
Section 308 -
03B .
z Bearing failure zOther part
failure.
z Raceways or
rollers.
z Lubricant.
z Towing vehicle
further than 80
km (50 miles)
with driveshaft
installed.
Mainshaft
tapered bearing
and needle
caged bearings
are especially
susceptible to
damage. z
REMOVE,
DISASSEMBLE and
CLEAN the
transmission. Inspect for
damaged parts and
install new components
as necessary. (Note:
RESET the bearing
preload if any new
tapered bearings are
installed). REFER to
Section 308 - 03A or
Section 308 - 03B .
z Vibration break-
up of retainer
and brinelling of
races.
z Bearing(s). z
DETERMINE the cause
of vibration and
CORRECT. Otherwise
PROCEED as above. Klj . 6 ba
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