12ENGINE
24
REPAIR Refit
8.Fit oil pump rotors in front cover.
9.Apply a bead of RTV sealant around retaining
plate.
10.Fit oil pump retaining plate to front cover,
securely tighten screws.
11.Fit front cover to cylinder block.
See Front
cover gasket
OIL PRESSURE RELIEF VALVE
Service repair no - 12.60.56
Remove
1.Remove engine oil sump.
See Engine oil
sump
2.Unscrew relief valve retaining plug from base of
front cover.
3.Withdraw valve spring and plunger and check for
wear.
Valve spring free length, 68.00 mm (2.68 in).
NOTE: If the valve plunger sleeve is badly
worn, pitted or scored, a new front cover
must be fitted.
See Front cover gasket
Always renew valve spring and plunger as a pair.
Refit
4.Insert valve plunger and spring into sleeve in
front cover and secure with retaining plug.
5.Fit engine oil sump.
See Engine oil sump
ENGINE
1
SPECIFICATIONS, TORQUE REV: 05/99 TORQUE VALUES
NOTE: Torque wrenches should be regularly checked for accuracy to ensure that all fixings are
tightened to the correct torque.
Nm
Engine block
Bearing cap 133...............................................................................................
Blanking plug, oil gallery, rear 37....................................................................
Oil squirt jet assembly 17................................................................................
Drain plug, cylinder block 25...........................................................................
Oil squirt jet, vacuum pump cam 7.................................................................
Connecting rod to cap 59................................................................................
Oil pick up assembly to bearing cap 9...........................................................
Oil pick up assembly to front cover 25............................................................
Camshaft thrust plate 9..................................................................................
Oil drain pipe to block (internal) 25.................................................................
Oil drain pipe to block (external) 25................................................................
Sump to cylinder block and front cover 25......................................................
Drain plug, oil sump 35...................................................................................
Tappet guide 14..............................................................................................
Breather side cover assembly 25....................................................................
Baffle plate to breather side cover 4..............................................................
Vacuum pump 25............................................................................................
Fuel lift pump 25.............................................................................................
Flywheel housing 45.......................................................................................
Flywheel housing clutch cover stud 10...........................................................
Plug, flywheel housing 12...............................................................................
Rear oil seal assembly 25...............................................................................
Oil filter adaptor 45..........................................................................................
Waxstat adaptor to oil filter adaptor 9............................................................
Oil pressure switch 17.....................................................................................
Oil filter, spin on 13.........................................................................................
Oil cooler unions to filter adaptor 45...............................................................
Oil level tube 25..............................................................................................
Engine mounting foot to cylinder block 85......................................................
Engine mounting foot to flywheel housing 45.................................................
Engine mounting foot rubber to mounting foot (bolt and nut) 85.....................
Flywheel to crankshaft 146..............................................................................
Clutch cover plate to flywheel 34....................................................................
Flex drive plate to crankshaft (auto) 146..........................................................
Flex drive plate to ring gear (auto) 25.............................................................
Flex drive plate to torque converter (auto) 45.................................................
FUEL SYSTEM
1
REPAIR FUEL INJECTION PUMP
Service repair no - 19.30.07
Remove
1.Disconnect battery.
2.Disconnect and remove high pressure fuel
injection pipes, pump to injectors.
3.Viewing valve mechanism through oil filler cap
aperture, turn crankshaft clockwise until No. 1
cylinder is just before TDC.
4.Remove blanking plug from flywheel housing
and fit timing toolLRT-12-044, locating centre
pin on flywheel.
NOTE: A chassis undertray may be fitted
on some vehicle derivatives to conform to
legal requirements. When under chassis
adjustments or remove and refit procedures are
required, it may be necessary to remove the
undertray and/or integral access panels
See
CHASSIS AND BODY, Repair, Front undertray
or
See CHASSIS AND BODY, Repair, Rear undertray
5.Carefully rotate crankshaft clockwise until centre
pin engages with timing slot in flywheel.
6.Remove injection pump access plate, complete
with gasket, from front cover plate.
7.Fit pin fromLRT-12-045to injection pump gear.
8.Restrain pulley nut to prevent straining timing
belt and remove drive gear to pump hub fixing
bolts and retaining plate.
9.Remove pin from pump gear.
10.Fit gear retaining toolLRT-12-045with an 8 mm
washer, 1,5 - 2 mm thick, under each bolt head
in addition to the existing washer.
11.Remove throttle cable and hand throttle cable, if
fitted.
12.Disconnect lead from fuel cut-off solenoid, and
EGR throttle position sensor multi-plug, if fitted.
FUEL SYSTEM
3
REPAIR FUEL INJECTORS
Service repair no - 19.60.10
Remove
NOTE: When a fuel injector is considered
to be the cause of irregular running and
loss of power it will be necessary to fit a
donor set of injectors to determine which injector
is at fault. DO NOT attempt to dismantle or carry
out spray tests on the fuel injectors. This work
can only carried out by authorised Bosch dealers.
1.Remove oil filler cap and release sound
insulation cover from top of engine.
2.Disconnect high pressure fuel supply pipes from
injectors and injection pump. Remove in pairs.
3.Disconnect spill return hose(s) from injectors.
4.Plug pipes and injector connections to prevent
the ingress of dirt and foriegn matter.5.Remove retaining nut and release each injector
clamp plate from cylinder head.
6.Remove injector and discard copper washer.
Refit
7.Ensure injectors and seating in cylinder head are
clean.
8.Lightly grease a new copper sealing washer and
position on each injector.
9.Fit injectors in cylinder head with spill return
outlets facing outward.
10.Secure injector with clamp plate and nut. Tighten
nut to
25 Nm (18 lbf/ft).
NOTE: The clamp plates are slightly
curved and should be fitted with the
convex side uppermost.
11.Fit the spill return pipe with a single copper
washer under the head of the banjo bolt and 2
copper washers fitted between the injector and
the banjo. Tighten banjo bolt to
10 Nm (7 lbf/ft).
12.Fit high pressure pipes to injectors and injection
pump. Tighten union nuts to
28 Nm (21 lbf/ft).
13.Fit sound insulation cover and oil filler cap.
COOLING SYSTEM
3
DESCRIPTION AND OPERATION COOLANT CIRCULATION
Operation
When the engine is started from cold the thermostat
(2) prevents coolant circulation through the radiator by
closing off the top hose (6). During the engine warm
up period the water pump (5) circulates coolant to the
cylinders in the crankcase and through separate ports
to the cylinder head. At the rear of the cylinder head a
proportion of the flow is diverted through a heater feed
pipe (16) to the matrix of the heater unit (15). The
coolant is then carried, via a heater return rail (14) and
hoses (7), back to the water pump. The remaining
coolant flows through a by-pass hose (9) at the
thermostat housing and back to the water pump to
complete the first cycle.
When the normal engine running temperature is
reached, the thermostat opens, closing off the by-pass
hose (9). Coolant is then circulated via the top hose
(6) and through the radiator, where it is cooled and
drawn from the radiator bottom hose (3) by the water
pump (5). The coolant circulation through the
crankcase and cylinder head remains the same.
Two bleed pipes (10) and (11) help control the system
pressure by purging excess air and coolant to the
expansion tank via the 'Y'piece ejector (12).VISCOUS FAN
Description
The viscous drive unit for the engine cooling fan,
provides a means of controlling the speed of the fan
relative to the running temperature of the engine. The
viscous unit is a type of fluid coupling, which drives
the fan blades by means of 'silicone fluid'.
1.Input (drive) member
2.Output (driven) member
3.Sensing mechanism (bi-metal coil)
The fan drive has to be engaged only periodically,
between 5% and 10%, during normal operating
conditions, because the engine is cooled by ram air
for most of the time.
30MANIFOLD AND EXHAUST SYSTEM
2
REPAIR Refit
11.Fit new gasket over manifold studs.
12.Loosely fit induction manifold lower nuts to
studs.
13.Fit exhaust manifold and secure with central
upper and lower nuts.
14.Locate heater rail to its correct position and
secure with outer exhaust manifold nuts.
15.Tighten all exhaust manifold nuts to
45 Nm (33
lbf/ft).
16.Tighten exhaust front pipe to intermediate
silencer nuts to
50 Nm (37 lbf/ft).
17.Fit turbocharger outlet pipe.
18.Fit induction manifold
See Induction manifold
.EXHAUST MANIFOLD/TURBOCHARGER
ASSEMBLY
Service repair no - 30.15.10
Remove
1.Remove induction manifold
See Induction
manifold
.
2.Disconnect turbocharger inlet hose.
3.Disconnect boost pressure pipe at turbocharger.
4.Remove intercooler bottom hose.
5.Place suitable container under engine and
disconnect turbocharger oil feed and return
pipes at cylinder block.
6.Remove 3 nuts securing exhaust front pipe to
manifold flange.
7.Remove 7 nuts and lift exhaust manifold and
turbocharger assembly from cylinder head.
8.Discard manifold gasket.
Refit
9.Fit new manifold gasket.
10.Position exhaust manifold assembly onto
location studs and secure to cylinder head.
Tighten nuts to
45 Nm (33 lbf/ft).
11.Secure exhaust front pipe to manifold flange.
Tighten fixings to
50 Nm (37 lbf/ft).
12.Reconnect turbocharger oil feed and return
pipes at cylinder block.
13.Fit intercooler bottom hose.
14.Fit boost pressure pipe at turbocharger.
15.Fit turbocharger inlet hose.
16.Fit induction manifold
See Induction manifold
.
CLUTCH
1
FAULT DIAGNOSIS CLUTCH ASSEMBLY CONDITIONS
For the clutch to operate correctly it is important the
following conditions are satisfied:-
·The primary shaft (15) must be free in the
crankshaft spigot bush (17).
·The friction plate (2) must be able to slide easily on
the splines on the primary shaft (15), to a position
where it does not contact either the flywheel or the
pressure plate.
·The friction plate must not be distorted or the
linings contaminated with oil, which may cause it to
stick or continue to run in contact with the flywheel
or pressure plate.
A number of faults can develop in the operation of the
clutch for a variety of reasons and most faults are due
to normal wear at high mileage. Problems can also
occur if the unit has been renewed by an unskilled
operator.
Recognising and diagnosing a particular clutch fault is
therefore of paramount importance in ensuring that
the problem is rectified at the first attempt.
Problems which develop in the clutch are as follows:-
·Clutch spin/drag
·Clutch slip
·Clutch judder/fierceCLUTCH SPIN - DRAG
Symptoms
Clutch spin is that, with engine running and clutch
pedal depressed, the gears cannot be immediately
engaged without making a grinding noise. This
indicates the clutch is not making a clean break.
However, if the clutch pedal is held depressed for
several seconds the friction plate will eventually break
free from the engine and the gear will engage silently.
Clutch spin as it becomes more severe develops into
clutch drag, making the silent engagement of a gear
impossible, regardless of how long the pedal is held
depressed.
CLUTCH SLIP
Symptoms
Clutch slip is most evident climbing a hill or when the
vehicle is moving off from stationary with a heavy
load. As the clutch is released, slip occurs between
the engine and the transmission, allowing the engine
speed to increase without a corresponding increase in
vehicle speed.
Clutch slip can develop to the stage where no power
is transmitted through the clutch as the pedal is
released.
CLUTCH JUDDER - FIERCE
Symptoms
Clutch judder or fierce engagement, like slip, is most
likely to occur when the vehicle is moving off from
stationary. As the clutch pedal is released the vehicle
will move rapidly or in a series of jerks, which cannot
be controlled even by careful operation of the clutch
by the driver.
It should be noted that a vehicle may display all the
symptoms or any combination of the symptoms
described, depending on the driving conditions vehicle
load and operating temperatures.
33CLUTCH
2
OVERHAUL
18.Place coil spring over valve stem.
19.Insert retainer into spring.
20.Compress spring and engage valve stem in
keyhole slot in retainer.
21.Fit seal, large diameter last, to piston.
22.Insert piston into spring retainer and engage
locking prong.
23.Smear piston with suitable rubber grease and
insert assembly, valve end first, into cylinder.
24.Fit push-rod, retaining washer and circlip.
25.Fit clutch master cylinder to vehicle
See Repair,
Master cylinder
.SLAVE CYLINDER - OVERHAUL
Service repair no - 33.35.07
Dismantle
1.Remove slave cylinder
See Repair, Slave
cylinder
.
2.Withdraw dust cover.
3.Expel piston assembly, applying low pressure air
to fluid inlet.
4.Withdraw spring.
5.Remove seal from piston.
6.Remove bleed valve.
Inspection
7.Clean all components with new hydraulic fluid
fluid and allow to dry.
8.Examine cylinder bore and piston, ensure that
they are smooth to touch with no corrosion,
score marks or ridges. If there is any doubt, fit
new components.
9.Renew seal and dust cover from slave cylinder
overhaul kit.