Engine System - General Information: Other Jaguar S-type I рестайлинг

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 UV 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, pre-mixed 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 pre-mixed, 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.

General Remarks

Note. Removing fuses and disconnecting electrical components causes the engine control module (ECM) to log an error message. After the measurements have been carried out this error message should be cleared from memory by connecting to the Jaguar Approved Diagnostic System.

Note. 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 operating temperature.

Check The Compression Pressure

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 components in reverse order, observing the specified tightening torques.
8. Reset the ECM fault memory.

Interpretation of the Results

The indicated compression pressure are considered within specification if the lowest reading cylinder is within 75% of the highest reading.

If the measurement on one or more cylinders is much lower than the specified value, spray some engine oil into the combustion chamber and repeat the compression measurement.

If the reading greatly improves then the piston rings are damaged.

If the reading stays the same then the cause is either damaged valve seats or valve stem seals.

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.

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 components become conditioned. Vehicles used in heavy-duty operation may use more oil. The following are examples of heavy-duty operation

1. Trailer towing applications.
2. Severe loading applications.
3. Sustained high speed operation.

Engines need oil to lubricate the following internal components

1. Cylinder block cylinder walls.
2. Pistons and piston rings.
3. Intake and exhaust valve stems.
4. Intake and exhaust valve guides.
5. 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

1. Engine size.
2. Operator driving habits.
3. Ambient temperatures.
4. Quality and viscosity of 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 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) per liter oil consumption rate is about 2,400 km (1,500 miles) per liter.

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.

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.

Scheme 22

1. NORMAL READING: Needle between 51-74 kPa (15-22 in-Hg) and holding steady.
2. NORMAL READING DURING RAPID ACCELERATION : When the engine is rapidly accelerated (dotted needle), the needle will drop to a low (not to zero) reading . 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.
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 BENT VALVES: A regular, evenly-spaced, down scale flicking of the needle indicates one or more burned or damaged valves. Insufficient hydraulic valve tappet or hydraulic lash adjuster clearance will also cause this reaction.
7. POOR VALVE SEATING: A small but regular down scale flicking can mean one or more valves are not seating correctly.
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, 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.

Pinpoint tests

Note. Where reference is made to 'suitable equipment', this refers to standard workshop equipment. Refer to the operating instructions for your own equipment when performing any tests.

Camshaft Journal Clearance - General Procedures

1. Position on a length of plastigage on the bearing cap. Insert the camshaft, without lubrication, into the cylinder head. Position a plastigage strip, which should be equal to the width of the bearing cap, on the bearing journal.
2. Install the camshaft bearing caps. Follow the relevant tightening sequence.
3. Remove the camshaft bearing caps. Follow the relevant loosening sequence.
4. Using the special tool, read off the measurement. Compare the width of plastigage with the plastigage scale. The value that is read off is the bearing clearance. If the values are not to specification install a new camshaft.

Scheme 23

1. Determine the diameter of the camshaft journals. Using a micrometer measure the diameter at 90 degrees intervals to determine if the journals are out-of-round. Measure at two different points on the journal to determine if there is any tapering. If the measurements are out of the specified range, install a new camshaft.

Scheme 24

1. Using the special tool, measure the end play. Slide the camshaft in both directions. Read and note the maximum and minimum values on the dial indicator gauge. End play = maximum value minus minimum value. If the measurement is out of specification, install new components.

Camshaft - General Procedures (-Lobe Lift)

1. Measure the diameter (1) and diameter (2) with a vernier caliper. The difference in measurements is the lobe lift.

Camshaft - General Procedures (-Lobe Surface)

1. Inspect camshaft lobes for pitting or damage in the active area. Minor pitting is acceptable outside the active area.

Connecting Rod Cleaning - General Procedures

1. Mark and separate the parts and clean with solvent. Clean the oil passages.

Connecting Rod Large End Bore - General Procedures

1. Measure the bearing bore in two directions. The difference is the connecting rod bore out-of-round. Verify the out-of-round is within specification.
2. Measure the bearing bore diameter in two directions. Verify the bearing bore is within specification.

Crankshaft End Play - General Procedures

1. Using the Dial Indicator Gauge with Brackets, measure the end play. Measure the end play by lifting the crankshaft using a lever. If the value is out of the specification, install new thrust half rings to take up the end float and repeat the measurement.

Scheme 25

Crankshaft Main Bearing Journal Clearance - General Procedures

Scheme 26

Cylinder Bore Out-of-Round - General Procedures

1. Measure the cylinder bore with an internal micrometer. Carry out the measurements in different directions and at different heights to determine if there is any out-of-roundness or tapering. If the measurement is out of the specified range, hone out the cylinder block or install a new block.

Scheme 27

1. Measure the cylinder block/cylinder head distortion. Using the special tool, measure the mating face distortion. If the value is not to specification rework the mating face.

Piston Pin Diameter - General Procedures

1. Measure the piston pin diameter. Measure the diameter in two directions. If the values are not to specification, install a new piston and a new piston pin.

Piston Pin to Bore Diameter - General Procedures

1. Measure the diameter of the piston pin bore. Measure the diameter in two directions. If the values are not to specification, install both a new piston and a new piston pin.

Scheme 28

1. Using the Feeler Gauge, measure the piston ring gap. The values given in the specification refer to a gauge ring used during production.

Scheme 29

1. Using the Feeler Gauge, measure the piston ring clearance.

Valve Spring Free Length - General Procedures

1. Using a vernier gauge, measure the free length of each valve spring. Verify the length is within specification.

Scheme 30

1. Using a micrometer measure the diameter of the valve stems. If the measurements are not to specification, install a new valve.