
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

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.

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
www.JagDocs.com

Published: 09-Apr-2014
Engine System - General Information - Cylinder Compression Test V8 S/C 5.0L
Petrol
General Procedures
Check
CAUTION: Before disconnecting or removing components, make sure the area around the joint faces and connections are
clean. Plug open connections to prevent contamination.
NOTES:
Removal steps in this procedure may contain installation details.
Some variation in the illustrations may occur, but the essential information is always correct.
The vehicle battery must be in good condition and fully charged before carrying out this procedure.
1. Refer to: Ignition Coil-On-Plug - V8 S/C 5.0L Petrol (303-07B Engine Ignition - V8 5.0L Petrol/V8 S/C 5.0L Petrol, Removal and Installation).
2. CAUTION: Make sure the fuel injection system is
disabled before carrying out a cylinder compression test.
Failure to follow this step may result in damage to the
vehicle.
Repeat procedure for the other side.
3. Crank engine for approximately five seconds to remove any remaining
fuel in the cylinders. www.JagDocs.com

1 Advance chamber 2 Retard chamber 3 Sprocket housing 4 Rotor assembly 5 Lock pin 6 Sleeve 7 Engine oil supply from camshaft 8 Inlet check valve 9 Lock pin drain 10 Spool valve 11 Advance check valve 12 Retard check valve At engine start-up, once the engine oil pressure in the camshaft is sufficient to open the inlet check valve, engine oil flows
across the spool valve, through the advance and retard check valves and into the advance and retard chambers. During the
start cycle, the ECM signals the VCT solenoid to move the spool valve into the sleeve and connect the lock pin to inlet oil

Variable Camshaft Timing Unit Schematic - Advance
To advance the camshaft timing, the ECM adjusts the signal to the VCT solenoid to move the spool valve so that the advance chamber oil passage is closed and the retard chamber oil passage is connected to inlet oil.
Each momentary increase of the torque acting on the camshaft generates a pressure pulse in the retard chamber. Oil moves
from the retard chamber, through the spool valve and the advance check valve to the advance chamber, to equalize the
pressures in the two chambers. The displacement of oil from the retard chamber causes the rotor assembly to advance in
relation to the sprocket housing. Each momentary decrease of torque acting on the camshaft also generates a pressure pulse
in the advance chamber, but, with the advance chamber oil passage closed, no movement of oil between the advance and
retard chambers occurs and the rotor assembly cannot move in the retard direction.

chamber oil passage and connect the advance chamber oil passage to the inlet oil.
Each momentary decrease of the torque acting on the camshaft causes oil to transfer from the advance chamber, through the
spool valve and the retard check valve to the retard chamber, and so retard the camshaft timing. www.JagDocs.com

Operating Temperature Range -40 to 160 °C (-40 to 320 °F) Oil Level Check
For additional information, refer to Engine Oil Draining and Filling (303-01A, General Procedures).
For accuracy, oil level checks should be performed with the vehicle on level ground when the oil is hot. The vehicle needs to
stand for approximately 10 minutes, after the engine is switched off, to allow the oil to drain back into the sump pan and the
oil level to stabilize. The oil level system will not give a reading until the oil level has stabilized.
With the ignition on, the engine stopped and the transmission in P (park), repeatedly press the trip button on the end of the
LH multifunction switch until the oil level icon and applicable message are displayed in the fuel gage/trip computer area of the message center, as shown below:
Item Description A Oil level is between 50% and 100% of recommended level. No top-up required. B Oil level is between 12.5% and 50% percent of recommended level. Add 0.5 liter (0.53 US quart) of oil. C Oil level is between 0% and 12.5% of recommended level. Add 1 liter (1.06 US quarts) of oil. D Oil level is above maximum for safe operation. Reduce oil level to recommended level. E Oil level is below minimum for safe operation. Add 1.5 liters (1.59 US quarts) of oil, then recheck level. F Oil level is stabilizing. Wait 10 minutes and then recheck level. If this display is accompanied by the message ENGINE OIL LEVEL MONITOR SYSTEM FAULT, a fault with the oil level monitoring system is indicated. System Fault Warning
If there is a fault with the system, in addition to being displayed during an oil level check, the message ENGINE OIL LEVEL
MONITOR SYSTEM FAULT will be temporarily displayed when the ignition is first switched on.