engine oil JAGUAR XFR 2010 1.G User Guide
Page 268 of 3039
DTC Description Possible Causes Action U0401-08
Invalid Data Received
From ECM/PCM A - Bus
Signal Message Failures
Inaccurate engine speed,
torque information
Check Engine Control Module for stored DTCs,
Check CAN Bus circuit for faults U0401-68
Invalid Data Received
from ECM/PCM A - Event
information
Inaccurate engine speed,
torque information
Check Engine Control Module for stored DTCs.
Check CAN Bus Circuit for fault U0401-86
Invalid Data Received
from ECM/PCM A - Signal
Invalid
Inaccurate engine speed,
torque information
Check Engine Control Module for stored DTCs.
Check CAN Bus Circuit for fault U0404-68
Invalid Data Received
from Gear Shift Control
Module A - Event
information
Incorrect CAN data
received from
Transmission Shift
Module
Check Transmission Shift Module for stored DTCs.
Refer to Circuit diagrams and check CAN and LIN
Bus for Circuit fault U0404-81
Invalid Data Received
from Gear Shift Control
Module A - Invalid Serial
Data Received
Incorrect LIN data
received from
Transmission Shift
Module
Check Transmission Shift Module for stored DTCs.
Refer to Circuit diagrams and check CAN and LIN
Bus for Circuit fault U0416-68
Invalid Data Received
From Vehicle Dynamics
Control Module - Event
information
Event information brake
information
Check Engine Control Module for stored DTCs.
Check CAN Bus Circuit for fault U0422-68
Invalid Data Received
From Body Control
Module - Event
information
Event information invalid
Power mode information
Check Central Junction Box for stored DTCs. Check
CAN Bus Circuit for fault U101B-87
Lost Communication With
GSM - Multiple Bus -
Missing message
Missing message lost
communication with
Transmission Shift
Module (multiple Bus)
Check Transmission Shift Module for stored DTCs.
Refer to Circuit diagrams and check CAN and LIN
Bus for Circuit fault U3000-49
Control Module - Internal
electronic failure
Internal electronic failure
Suspect the Transmission Control Module. Install a
new Transmission Control Module as required,
refer to the warranty policy and procedures manual
if a module/component is suspect. U3000-4B
Control Module - Circuit
resistance above
threshold
Internal electronic failure
Check and correct oil level. Check hydraulic flow
through oil cooler and pipe circuit for restriction or
blockage. If no restrictions found, suspect the
Transmission Control Module. Install a new
Transmission Control Module as required, refer to
the warranty policy and procedures manual if a
module/component is suspect. U3000-81
Control Module - Invalid
serial data received
Vehicle or Engine type
signal incorrect from
Central Junction Box or
incorrect Transmission
Control Module software
installed
Reflash the Transmission Control Module using the
manufacturer approved process U3001-94
Control Module Improper
Shutdown - Unexpected
operation
Control Module Improper
Shutdown (voltage
related)
Check Engine Control Module For Power
(alternator) faults. Check Power and Ground
Circuit and Battery for fault. Clear DTCs. Road
Test. If DTC reoccurs suspect the Transmission
Control Module. Install a new Transmission Control
Module as required, refer to the warranty policy
and procedures manual if a module/component is
suspect.
Page 332 of 3039
Upper Control Arm
The forged-aluminum upper control arm is a wishbone design and connects to the vehicle body through two plain bushes, and
links to the swan neck wheel knuckle by an integral ball joint. The upper control arm is inclined to provide anti-dive
characteristics under heavy braking, while also controlling geometry for vehicle straight-line stability.
Lower Control Arm
The forged aluminum lower control arms are of the wishbone design; the arms separate to allow for optimum bush tuning:
The rear lateral control arm is fitted with a bush at its inner end which locates between brackets on the subframe. The
arm is secured with an eccentric bolt which provides the adjustment of the suspension camber geometry. The outer end
of the control arm has a tapered hole which locates on a ball joint fitted to the wheel knuckle. An integral clevis bracket
on the forward face of the lateral control arm allows for the attachment of the forward control arm. A bush is fitted
below the clevis bracket to provide for the attachment of the stabilizer bar link. A cross-axis joint is fitted to a
cross-hole in the control arm to provide the location for the clevis attachment of the spring and damper assembly.
The forward control arm is fitted with a fluid-block rubber bush at its inner end which locates between brackets on the
subframe. The arm is secured with an eccentric bolt which provides adjustment of the castor and camber geometry. The
outer end of the control arm is fitted with a cross-axis joint and locates in the integral clevis bracket on the lateral
control arm.
Wheel Knuckle
The cast aluminum wheel knuckle is a swan neck design and attaches to the upper control arm and lower lateral control arm.
The lower lateral control arm locates on a non serviceable ball-joint integral with the wheel knuckle. The lower boss on the
rear of the knuckle provides for the attachment of the steering gear tie-rod ball joint.
The wheel knuckle also provides the mounting locations for the:
wheel hub and bearing assembly
the wheel speed sensor (integral to the wheel hub and bearing assembly)
brake caliper and disc shield.
Stabilizer Bar
The stabilizer bar is attached to the front of the subframe with bushes and mounting brackets. The pressed steel mounting
brackets locate over the bushes and are attached to the cross member with bolts screwed into threaded locations in the
subframe. The stabilizer bar has crimped, 'anti-shuffle' collars pressed in position on the inside edges of the bushes. The
collars prevent sideways movement of the stabilizer bar.
The stabilizer bar is manufactured from 32mm diameter tubular steel on supercharged models and 31mm diameter tubular
steel on diesel and normally aspirated models and has been designed to provide particular characteristics in maintaining roll
rates, specifically in primary ride comfort.
Each end of the stabilizer bar curves rearwards to attach to a ball joint on a stabilizer link. Each stabilizer link is secured to a
bush in the lower lateral arm with a bolt and locknut. The links allow the stabilizer bar to move with the wheel travel providing
maximum effectiveness.
The only difference between the front stabilizer bars, in addition to the diameter, is in the shape to accommodate engine
variant:
a slightly curved bar, between bush centers, for V6 diesel (31 mm dia) and V8 gasoline supercharged (32 mm dia),
a straight bar, between bush centers, for V6 and V8 normally aspirated gasoline engines (31 mm dia).
Spring and Damper Assembly
The spring and damper assemblies are located between the lower lateral arm and the front suspension housing in the inner
wing. Dependant on vehicle model there are three types of coil spring and damper available:
a standard oil passive damper (All models except supercharged),
an adaptive damper, also known as Computer Active Technology Suspension (CATS) on 4.2L supercharged vehicles up to
2010MY, For additional information refer to Vehicle Dynamic Suspension 4.2L.
a continuously variable adaptive damper, also known as Adaptive Dynamics System on 5.0L supercharged vehicles from
2010MY. For additional information refer to Vehicle Dynamic Suspension 5.0L.
The dampers are a monotube design with a spring seat secured by a circlip onto the damper tube. The damper's lower
spherical joint is an integral part of the lateral lower control-arm, and the damper takes the form of a clevis-end, which
straddles the spherical joint.
The damper piston is connected to a damper rod which is sealed at its exit point from the damper body. The threaded outer
end of the damper rod locates through a hole in the top mount. A self locking nut secures the top mount to the damper rod.
The damper rod on the adaptive damper has an electrical connector on the outer end of the damper rod.
Supercharged 4.2L vehicles up to 2010MY: The adaptive damper functions by restricting the flow of hydraulic fluid through
internal galleries in the damper's piston. The adaptive damper has a solenoid operated valve, which when switched allows a
greater flow of hydraulic fluid through the damper's piston. This provides a softer damping characteristic from the damper. The
adaptive damper defaults to a firmer setting when not activated. The solenoid is computer controlled and can switch between
soft and hard damping settings depending on road wheel inputs and vehicle speed.
Supercharged 5.0L vehicles from 2010MY: The variable damper functions by adjustment of a solenoid operated variable orifice,
which opens up an alternative path for oil flow within the damper. When de-energized the bypass is closed and all the oil flows
Page 484 of 3039
each damper to the appropriate level to maintain a flat and level body.
Roll Rate Control – Uses CAN inputs. Predicts vehicle roll rate due to driver steering inputs 100 times a second and increases damping to reduce roll rate.
Pitch Rate Control – Uses CAN inputs. Predicts vehicle pitch rate due to driver throttle and braking inputs 100 times a second and increases damping to reduce pitch rate.
Bump Rebound Control – Uses suspension height sensor and CAN inputs. Monitors the position of the wheel 500 times a second and increases the damping rate as the damper approaches the end of its travel.
Wheel Hop Control – Uses suspension height sensor and CAN inputs. Monitors the position of the wheel 500 times a second and detects when the wheel is at its natural frequency and increases the dampingto reduce vertical wheel
motion.
Under normal road conditions when the vehicle is stationary with the engine running, the dampers are set to the firm condition
to reduce power consumption.
The adaptive damping module receives its power supply via a relay and fuse in the CJB. The relay remains energized for a period of time after the ignition is off. This allows the adaptive damping module to record and store any DTC (diagnostic
trouble code) relating to adaptive dynamics system faults.
DAMPERS Component Description
Item Description A Front spring and damper assembly B Rear spring and damper assembly The 'Adaptive Dynamics' dampers are monotube, nitrogen gas and oil filled units, manufactured by Bilstein. The dampers are
continuously variable, which allows the damping force to be electrically adjusted when the vehicle is being driven. The variable
dampers provide the optimum compromise between vehicle control and ride comfort.
The dampers have an electrical connector on the end of the piston rod, in the center of the top mount (the dampers look
identical to those on the Computer Active Technology Suspension (CATS) system of 4.2L supercharged vehicles, but have a
different part number).
In each damper, the continuous damping adjustment is achieved by a solenoid operated variable orifice, which opens up an
alternative path for oil flow within the damper. When de-energized the bypass is closed and all the oil flows through the main
(firm) piston. When energized, the solenoid moves an armature and control blade, which work against a spring. The control
blade incorporates an orifice which slides inside a sintered housing to open up the bypass as required. In compression, oil
flows from the lower portion of the damper through a hollow piston rod, a separate soft (comfort) valve, the slider housing and
orifice and into the upper portion of the damper, thereby bypassing the main (firm) valve. In rebound the oil flows in the www.JagDocs.com
Page 502 of 3039
Symptom Possible Cause Action rear drive halfshaft
Wheel bearings, brakes or
suspension components Vibration at highway speeds
Out-of-balance wheel(s) or tire(s)
Driveline out of
balance/misalignment
Driveshaft center bearing touching
body mounting point
Balance and install new wheel(s) and tire(s)
as required
REFER to: Wheel and Tire (204-04 Wheels and Tires, Removal and Installation).
For additional information,
REFER to: Driveline Angle Inspection (205-00 Driveline System - General Information,
General Procedures).
Refer to the Manufacturer approved
diagnostic system for driveshaft balancing
application
Check for correct spacer washer thickness.
Inspect and install new washers as required Shudder, Vibration During
Acceleration
Powertrain/driveline misalignment
High constant velocity (CV) joint
operating angles caused by
incorrect ride height
Check for misalignment. Install new
components as required. For driveshaft
alignment,
REFER to: Driveline Angle Inspection (205-00 Driveline System - General Information,
General Procedures).
Check the ride height and verify the correct
spring rate. Install new components as
required Lubricant Leak
Rear drive axle breather
Damaged seal
Rear drive axle filler plug
Rear drive axle rear cover joint
Check oil level and correct as required
Install new components as required Pinpoint Tests
PINPOINT TEST A : EXCESSIVE DRIVELINE NOISE TEST
CONDITIONS DETAILS/RESULTS/ACTIONS A1: CHECK NOISE FROM VEHICLE ON ROAD TEST 1 Road test vehicle to determine load and speed conditions when noise occurs. 2 Assess the noise with different gears selected. Does the noise occur in different gears at the same vehicle speed? Yes
Install a new rear drive axle/differential assembly.
REFER to: Axle Assembly - V6 3.0L Petrol (205-02 Rear Drive Axle/Differential, Removal and Installation).
Re-test the system for normal operation.
No
Suspect the engine or transmission. For additional information, REFER to:
Engine - 3.0L/4.2L (303-00 Engine System - General Information, Diagnosis and Testing), Engine - 2.7L Diesel (303-00 Engine System - General Information, Diagnosis and Testing), Diagnostic Strategy (307-01A Automatic Transmission/Transaxle - V6 3.0L Petrol, Diagnosis and Testing).
Page 688 of 3039
Published: 08-Oct-2012
Power Brake Actuation - Brake Vacuum Pump V8 5.0L Petrol/V8 S/C 5.0L
Petrol
Removal and Installation
Removal
CAUTION: Make sure that all openings are sealed. Use new blanking caps.
NOTE: Removal steps in this procedure may contain installation details.
1. WARNING: Make sure to support the vehicle with axle stands.
Raise and support the vehicle.
2. Refer to: Engine Oil Draining and Filling (303-01, General Procedures).
3.
4. CAUTION: Be prepared to collect escaping oil.
Torque: 12 Nm
Page 811 of 3039
Engine System - General Information - Engine 5.0L
Diagnosis and Testing
Special Tool(s)
Oil pressure testing adaptor, 303-1451
Oil pressure testing gauge, 303-871 Principle of Operation Published: 11-May-2011
For a detailed description of the 5.0L engine, refer to the relevant Description and Operation sections in the workshop manual.
REFER to:
Engine (303-01C Engine - V8 5.0L Petrol, Description and Operation), Engine (303-01C Engine - V8 5.0L Petrol, Description and Operation), Engine (303-01C Engine - V8 5.0L Petrol, Description and Operation), Engine (303-01D Engine - V8 S/C 5.0L Petrol, Description and Operation), Engine (303-01D Engine - V8 S/C 5.0L Petrol, Description and Operation), Engine (303-01D Engine - V8 S/C 5.0L Petrol, Description and Operation).
Inspection and Verification
1. Verify the customer concern.
2. Visually inspect for obvious signs of damage and system integrity.
Visual Inspection
Mechanical Electrical Coolant leaks
Oil leaks
Leaks in the fuel system
Visibly damaged or worn parts
Loose or missing fixings Fuses
Loose or corroded electrical connectors
Harnesses
Sensors
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to
the next step.
4. If the concern is not visually evident, verify the symptom and refer to the Symptom Chart, alternatively check for
Diagnostic Trouble Codes (DTCs) and refer to the relevant DTC Index.
Symptom Chart
NOTES:
If an engine is suspect, and the vehicle remains under the Manufacturers warranty refer to the Warranty Policy and
Procedure manual (section B1.2), or determine if any prior approval programme is in operation, prior to the installation of a
new engine.
Due to the possibility of loose carbon, that has become trapped between the valve face and seat, effecting the pressure
readings, when carrying out a compression test and some cylinders are found to have low pressures, install the spark plugs,
road test the vehicle and re-test the suspect cylinders. If the correct pressures are restored, no further action is required. www.JagDocs.com
Page 812 of 3039
Symptom Action All engine related issues
Check ECM for Diagnostic Trouble Codes (DTCs) and refer to DTC Index. REFER to:
Electronic Engine Controls (303-14C Electronic Engine Controls - V8 5.0L Petrol, Diagnosis and Testing),
Electronic Engine Controls (303-14D Electronic Engine Controls - V8 S/C 5.0L Petrol, Diagnosis and Testing). Difficult to start hot and
cold
Carry out general engine checks:
- Compression test. Refer to component tests in this section.
- Valve clearances
- Spark plug condition and color Poor idle
Ensure the air intake system is free from leaks
Carry out general engine checks:
- Compression test. Refer to component tests in this section.
- Valve clearances
- Spark plug condition and color
Check for collapsed catalytic converter/blocked exhaust system
Check long and short term fuel trim datalogger signals
- Readings up to 10%: may be considered as acceptable if the readings are equal
bank to bank
- Positive readings of between 10-20%: check for air leaks in air intake system
- Negative readings of between 10-20%: check for over fuelling e.g. leaking injectors,
high fuel pressure
- Readings above 20%: check for DTCs and refer to DTC Index. REFER to:
Electronic Engine Controls (303-14C Electronic Engine Controls - V8 5.0L Petrol, Diagnosis and Testing),
Electronic Engine Controls (303-14D Electronic Engine Controls - V8 S/C 5.0L Petrol, Diagnosis and Testing).
Carry out a vacuum gauge check. Refer to component tests in this section Insufficient
power/Insufficient
compression
Ensure the air intake system is free from leaks
Carry out general engine checks:
- Compression test. Refer to component tests in this section.
- Valve clearances
- Spark plug condition and color
Check for collapsed catalytic converter/blocked exhaust system
Check long and short term fuel trim datalogger signals
- Readings up to 10%: may be considered as acceptable if the readings are equal
bank to bank
- Positive readings of between 10-20%: check for air leaks in air intake system
- Negative readings of between 10-20%: check for over fuelling e.g. leaking injectors,
high fuel pressure
- Readings above 20%: check for DTCs and refer to DTC Index. REFER to:
Electronic Engine Controls (303-14C Electronic Engine Controls - V8 5.0L Petrol, Diagnosis and Testing),
Electronic Engine Controls (303-14D Electronic Engine Controls - V8 S/C 5.0L Petrol, Diagnosis and Testing).
Carry out a vacuum gauge check. Refer to component tests in this section Oil consumption
Carry out oil leak check followed by an oil consumption test. Refer to the component tests
in this section
If oil consumption is excessive:
Check the integrity of the engine breather system
Carry out general engine checks:
- Compression test. Refer to component tests in this section.
- Valve clearances
- Spark plug condition and color Noise
Refer to the Special Service Messages on the Electronic Product Quality Report (EPQR)
system for sound files. If the symptom does NOT compare to any of the sound files,
contact Dealer Technical Support (DTS) DTC Index
For a list of DTCs that could log in the Engine Control Module (ECM) refer to section 303-14. REFER to:
Electronic Engine Controls (303-14C Electronic Engine Controls - V8 5.0L Petrol, Diagnosis and Testing), Electronic Engine Controls (303-14D Electronic Engine Controls - V8 S/C 5.0L Petrol, Diagnosis and Testing).
Page 813 of 3039
Component Tests
Engine Oil Leaks
NOTE: Before installing new gaskets or oil seals, make sure that the fault is clearly established.
If the oil leak cannot be identified clearly by a visual inspection, carry out an Ultraviolet test:
Fluorescent Oil Additive Method
1. Clean the engine with a suitable cleaning fluid (brake cleaner).
2. Drain the engine oil and refill with recommended oil, premixed with Diesel Engine Oil Dye or equivalent. Use a minimum
14.8 ml (0.5 ounce) to a maximum 29.6 ml (1 ounce) of fluorescent additive to all engines. If oil is not premixed,
fluorescent additive must first be added to the crankcase.
3. Run engine for 15 minutes. Stop the engine and inspect all seal and gasket areas for leaks using a 12 Volt Master UV
Diagnostic Inspection Kit or equivalent. A clear bright yellow or orange area will identify leak. For extremely small
leaks, several hours may be required for the leak to appear.
4. As necessary, pressurize the main oil gallery system to locate leaks due to incorrectly sealed, loose or cocked plugs. If
the flywheel bolts leak oil, look for sealer on the threads.
5. Repair all leaks as necessary.
Compression Test General Remarks
NOTES:
Removing fuses and disconnecting electrical components may cause the Engine Control Module (ECM) to log Diagnostic
Trouble Codes (DTCs). After the measurements have been carried out, DTCs should be cleared from memory by connecting to
the Manufacturer Approved Diagnostic System.
Only check the compression pressure with the valves set to the prescribed clearance (if this can be adjusted).
The compression pressure should be checked with the engine at normal operating temperature.
Check the Compression Pressure
WARNING: Move gear selector lever to 'P' position. Failure to follow this instruction may result in personal injury.
1. Remove the fuel pump relay.
2. Start the engine - the engine will start, run for a few seconds then stall.
3. Remove the spark plugs.
4. Install the compression tester.
5. Install an auxiliary starter switch in the starting circuit. With the ignition switch OFF, using the auxiliary starter switch,
crank the engine a minimum of five compression strokes and record the highest reading. Note the approximate number
of compression strokes required to obtain the highest reading.
6. Repeat the test on each cylinder, cranking the engine approximately the same number of compression strokes.
7. Install the removed components in reverse order, observing the specified tightening torques.
8. Clear all DTCs from the ECM.
Interpretation of the Results
NOTE: Due to the possibility of loose carbon that has become trapped between the valve face and seat effecting the
pressure readings, when carrying out a compression test and cylinders are found to have low pressures, install the spark plugs,
road test the vehicle and re-test the suspect cylinders. If the correct pressures are restored, no further action is required.
The indicated compression pressures are considered within specification if the lowest reading cylinder is within 75% of the
highest reading.
If the cylinder pressures are found to be low, carry out a leakdown test to determine the location of the fault (if any leakback
can be heard through the engine breather system suspect the piston rings, if any leakback can be heard through the inlet
system suspect the inlet valve or seat, if any leakback can be heard through the exhaust manifold suspect the exhaust valve
or seat. If the measurements for two cylinders next to each other are both too low then it is very likely that the cylinder head
gasket between them is burnt through. This can also be recognized by traces of engine oil in the coolant and/or coolant in the
Page 814 of 3039
engine oil).
Oil Consumption Test
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
components become conditioned. Vehicles used in heavy-duty operation may use more oil. The following are examples of
heavy-duty operation:
Trailer towing applications
Severe loading applications
Sustained high speed operation
Engines need oil to lubricate the following internal components:
Cylinder block cylinder walls
Pistons and piston rings
Intake and exhaust valve stems
Intake and exhaust valve guides
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 are examples of conditions that can affect oil consumption rates:
Engine size
Operator driving habits
Ambient temperatures
Quality and viscosity of oil
Engine is 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. The oil level should not be above the top of the cross-hatched area and the letter "F"
in FULL).
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 mark on the oil level indicator due to dilution (condensation and fuel) in the
engine crankcase. The vehicle then might 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 of oil was used in about 160 km (100 miles). Oil
consumption rate is about one liter per 2,400 km (1,500 miles).
Make sure the selected engine oil meets Jaguar specification and the recommended API performance category "SG" and 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 for the typical operating conditions.
The following diagnostic procedure is used to determine the source of excessive oil consumption.
NOTE: Oil use is normally greater during the first 16,100 km (10,000 miles) of service. As mileage increases, oil use
decreases. High speed driving, towing, high ambient temperature and other factors may result in greater oil use.
1. Define excessive consumption, such as the number of miles driven per liter of oil used. Also determine customers
driving habits, such as sustained high speed operation, towing, extended idle and other considerations.
2. Verify that the engine has no external oil leaks as described under Engine Oil Leaks in this section.
3. Carry out an oil consumption test:
Run the engine to normal operating temperature. Switch engine OFF and allow oil to drain back for at least five
minutes .
With vehicle parked on level surface, check the engine oil level.
If required, add engine oil to set level exactly to the FULL mark.
Record the vehicle mileage.
Instruct the customer to return for a level check after driving the vehicle as usual for 1,610 km (1000 miles).
Check the oil level under the same conditions and at the same location as the initial check.
NOTE: If the oil consumption rate is unacceptable go to Step 4.
4. Check the Positive Crankcase Ventilation (PCV) system. Make sure the system is not plugged.
5. Check for plugged oil drain-back holes in the cylinder head and cylinder block.
6. If the condition still exists after carrying out the above tests go to step 9.
7. Carry out a cylinder compression test. Refer to the Compression Test procedure in this section. This can help determine
the source of oil consumption such as valves, piston rings or other areas.
8. Check valve guides for excessive guide clearance. Install new valve stem seals after verifying valve guide clearance.
9. Worn or damaged internal engine components can cause excessive oil consumption. Small deposits of oil on the tips of
the spark plugs can be a clue to internal oil consumption.
Page 816 of 3039
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 RETARDED: 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, 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.
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
such as the power brake booster, the unit will not function correctly. Always repair vacuum leaks.
Engine Oil Pressure Check
NOTE: Prior to checking the engine oil pressure, a road test of 6 miles (10 kilometres), must be carried out. Do not
attempt to attain engine normal operating temperature by allowing the engine to idle.
1. Disconnect the battery ground cable. Refer to section 414-00 - Charging System - General Information of the workshop
manual
2. WARNINGS:
The spilling of hot engine oil is unavoidable during this procedure, care must be taken to prevent scalding.
Wear protective gloves.
Remove the engine oil filter element
REFER to: Oil Filter Element (303-01C Engine - V8 5.0L Petrol, Removal and Installation).
NOTE: Ensure the oil filter element is not contaminated during this procedure
3. Install the oil filter element into special tool (Oil filter adapter number 303-1451)
4. Install the special tool (Oil filter adapter number 303-1451) to the engine. Torque: 25 Nm
5. Install the special tool (Oil pressure testing gauge, 303-871) and tighten the union
6. Connect the battery ground cable
7. Refer to owner hand book, check and top-up the engine oil if required
8. Start and run the engine
9. Note the oil pressure readings with the engine running at idle and 3500 RPM
10.
Turn off the engine
11.
Disconnect the battery ground cable
12. Remove the special tools
1. Clean the components
13.
Install the engine oil filter element
REFER to: Oil Filter Element (303-01C Engine - V8 5.0L Petrol, Removal and Installation).
NOTE: Ensure the oil filter element is not contaminated during this procedure
14.
Connect the battery ground cable
15. Refer to owner hand book, check and top-up the engine oil if required
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