low oil pressure FORD MUSTANG 2003 User Guide

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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Engines need oil to lubricate the following internal components:
zcylinder block cylinder walls
z pistons and piston, pin and rings (6102)
z intake and exhaust valve stems
z intake and exhaust valve guides
z all internal engine components
When the pistons move downward, a thin film of oil is left on the cylinder walls. As the vehicle is
operated, some oil is also drawn into the combustion chambers past the intake and exhaust valve
stem seals and burned.
The following is a partial list of conditions that can affect oil consumption rates:
zengine duty cycle
z operator driving habits
z ambient temperature
z quality and viscosity of the oil
Operation under varying conditions can frequently be misleading. A vehicle that has been run for
several thousand miles on short trips or in below- freezing ambient temperatures may have consumed
a "normal" amount of oil. However, when checking the engine oil level, it may measure up to the FULL
or MAX on the oil level dipstick due to dilution (condensation and fuel) in the engine crankcase. The
vehicle might then be driven at high speeds on the highway where the condensation and fuel boil off.
The next time the engine oil is checked, it may appear that a liter (quart) of oil was used in about 160
km (100 miles). This perceived 160 km (100 miles) per liter (quart) oil consumption rate causes
customer concern even though the actual overall oil consumption rate is about 2,400 km (1,500 miles)
per liter (quart).
Make sure the selected engine oil meets the current recommended API performance category with
SAE viscosity grade as shown in the vehicle Owner's Guide. It is also important that the engine oil is
changed at the intervals specified. Refer to the vehicle Owner's Guide.
Oil Pressure Test
1. Disconnect and remove the oil pressure sensor (9278) from the engine.
2. Connect the Oil Pressure Gauge to the oil pressure sender oil galley port.
3. Run the engine until normal operating temperature is reached.
4. Run the engine at the specified rpm and record the gauge reading.
5. The oil pressure should be within specifications; refer to the specification chart in the appropriate engine section.
6. If the pressure is not within specification, check the following possible sources: zinsufficient oil
z oil leakage
z worn or damaged oil pump
z oil pump screen cover and tube (6622)
z excessive main bearing clearance Klj . 13 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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4. Inspect for normal burning.
zCheck for light tan or gray deposits on the firing tip.
5. Inspect for pre- ignition, identified by melted electrodes and a possibly damaged insulator.
Metallic deposits on the insulator indicate engine damage. This may be caused by incorrect
ignition timing, wrong type of fuel or the unauthorized installation of a heli- coil insert in place of
the spark plug threads.
zInstall a new spark plug.
6. Inspect for overheating, identified by a white or light gray spots and with bluish- burnt
appearance of electrodes. This is caused by engine overheating, wrong type of fuel, loose spark
plugs, spark plugs with an incorrect heat range, low fuel pump pressure or incorrect ignition
timing.
zInstall a new spark plug. Klj . 2 ba
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A/C compressor bracket-
to-cylinder head stud bolt 25 18 —
Oil level indicator tube-
to-cylinder head bolt 10 — 89
Coolant recovery reservoir bracket-to-
GOP bolts 9 — 80
Motor mount-
to-subframe nuts 115 85 —
Oil pan drain plug 26 19 —
Wire harness bracket to motor mount nut 27 20 —
Steering column pinch bolt 47 35 —
Front subframe-
to-body bolts 90 66 —
Front subframe-
to-shock tower bolts 115 85 —
Oil pan-to-
cylinder block bolts a — — —
Oil pan-to-
transmission bell housing 45 33 —
Main bearing bridge nuts 32 24
Oil pump cover-
to-engine front cover bolts 25 18 —
Oil pump cover-
to-engine front cover bolt 10 89 —
Oil pickup tube-
to-cylinder block bolts 25 18 —
Oil pickup tube-
to-oil pan baffle nut 48 35 —
Flywheel-
to-crankshaft bolts 80 59 —
Wire harness bracket-
to-motor mount stud- nut 27 20 —
Engine ground strap-
to-motor mount nut 27 20 —
Motor mount-
to-motor mount bracket bolts 70 52 —
RH motor mount-
to-motor mount bracket nut 70 52 —
Hood ground strap-
to-hood hinge bolt 12 9 —
Hood hinge nuts 12 9 —
Generator mounting bracket 25 18 —
Power steering pump bracket nuts 8 — 71
Power steering pump bolts 25 18 —
Valve tappet guide plate bolts 12 9 —
Generator positive cable nut 10 — 89
Power steering pressure tube to pump nut 40 30 —
Accelerator cable bracket-
to-intake manifold bolts 10 — 89
42-
pin connector bolt 10 — 89
Transmission oil cooler tube bracket-
to-motor mount bracket nut 27 20
Torque converter-
to-flywheel nuts 36 27 —
Engine-
to-transmission bolts 40 30 —
Engine mount bracket-
to-engine bolts 70 52 —
Engine mount bracket-
to-engine nuts 70 52 —
Water pump pulley bolts 25 18 —
Oil filter
b — — —
Upper intake manifold-
to-lower intake manifold bolts a — — —
Lower intake manifold-
to-cylinder head bolts a — — —
Rocker arm pivot-
to-cylinder head bolts a — — — Klj . 5 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
Valve Seals
Removal and Installation 1. Remove the roller followers. For additional information, refer to Camshaft Roller Follower in this
section.
2. Remove the spark plug (12405) from the applicable cylinder.
3. Position the piston (6102) of the cylinder being serviced at the bottom of the stroke.
4. CAUTION: If air pressure has forced the piston to the bottom of the cylinder, any
loss of air pressure will allow the valve to fall into the cylinder. If air pressure must be
removed, support the valve prior to removal.
Use compressed air in the cylinder to hold both valves in position. 5. Using the special tool, compress the valve spring (6513). SECTION 303-
01B: Engine — 4.6L (2V) 2003 Mustang Workshop Manual Special Tool(s)
Valve Spring Compressor
303-
452 (T93P-6565- AR) Valve Stem Seal Replacer
303-
383 (T91P-6571- A) Compressor, Valve Spring
(Exhaust)
303-
567 (T97P- 6565- AH)
Material Item Specification
Super Premium SAE 5W-20
Motor Oil
XO- 5W20- QSP WSS-
M2C153-
H Klj . 1 ba
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IN-
VEHICLE REPAIR
Oil Filter Adapter
Removal and Installation 1. Drain the cooling system. For additional information, refer to Section 303 - 03A or
Section 303 -
03B .
2. Disconnect the lower radiator hose.
3. Raise and support the vehicle. For additional information, refer to Section 100 - 02 .
4. Drain the engine oil.
5. Disconnect the oil pressure sensor electrical connector.
SECTION 303-
01B: Engine — 4.6L (2V) 2003 Mustang Workshop Manual Material
Item Specification
Super Premium SAE 5W-20
Motor Oil
XO- 5W20 QSP or equivalent WSS-
M2C153-
H Premium Engine Coolant
VC-
4A (In Canada CXC- 10; In
Oregon VC- 5) or equivalent ESE-
M97B44-
A Klj . 1 ba
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14. Disconnect the vacuum line from the fuel pressure sensor. Item Part Number Description
1 — To crankshaft position sensor
2 — To A/C compressor
3 — To radio ignition interference capacitor (2)
4 — To fuel injectors (8)
5 — To ignition coils (8)
6 — To engine coolant temperature sensor
7 — To throttle position sensor
8 — To idle air control valve
9 — To EGR vacuum regulator
10 — To differential pressure feedback EGR
11 — To fuel pressure regulator
12 — Fuel injection ground
13 — To generator
14 — To camshaft position sensor
15 — To body
16 — To heated oxygen sensor (2)
17 — Engine bulkhead connector
18 — To low coolant sensor
19 — To body
20 — To power distribution box
21 — To body Klj . 5 ba
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Both cylinder heads
58. CAUTION: Do not use metal scrapers, wire brushes, power abrasive discs or other
abrasive means to clean the sealing surfaces. These tools cause scratches and gouges
that make leak paths. Use a plastic scraping tool to remove all traces of the head gasket.
CAUTION: Observe all warnings or cautions and follow all application directions
contained on the packaging of the silicone gasket remover and the metal surface prep.
NOTE: If there is no residual gasket material present, metal surface prep can be used to clean
and prepare the surfaces.
Clean the cylinder head- to-cylinder block mating surfaces of both the cylinder head and the
cylinder block. 1. Remove any large deposits of silicone or gasket material with a plastic scraper.
2. Apply silicone gasket remover, following package directions, and allow to set for several minutes.
3. Remove the silicone gasket remover with a plastic scraper. A second application of silicone gasket remover may be required if residual traces of silicone or gasket material
remain.
4. Apply metal surface prep, following package directions, to remove any remaining traces of oil or coolant, and to prepare the surfaces to bond with the new gasket. Do not attempt
to make the metal shiny. Some staining of the metal surfaces is normal.
59. NOTE: The straightedge used must be flat within 0.0051 mm (0.0002 in) per foot of tool length.
Support the cylinder head on a bench with the head gasket side up. Inspect all areas of the
deck face with a straightedge, paying particular attention to the oil pressure feed area. The
cylinder head must not have depressions deeper than 0.0254 mm (0.001 in) across a 38.1 mm
(1.5 in) square area, or scratches more than 0.0254 mm (0.001 in) . Klj . 20 ba
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