1999 LAND ROVER DISCOVERY tow

ENGINE - V8
OVERHAUL 12-2-65
11.Check the following valve dimensions. Renew
valves as necessary.
lValve head diameter 'A': Inlet = 39.75 to
40.00 mm (1.56 to 1.57 in).
lValve head diameter 'A': Exhaust = 34.23 to
34.48 mm (1.35 to 1.36 in).
lValve stem diameter 'B': Inlet = 8.664 to
8.679 mm (0.341 to 0.342 in).
lValve stem diameter 'B': Exhaust – 4.0 litre
engines up to engine nos. 55D 05677A; 56D
50787A and 97D 05504A = 8.651 to 8.666
mm (0.340 to 0.341 in).
lValve stem diameter 'B': Exhaust – 4.0 litre
engines from engine nos. 55D 05678A; 56D
50788A and 97D 05505A and all 4.6 litre
engines = 8.641 to 8.656 mm (0.340 to
0.341 in)
12.Check installed height of valve.
lValve installed height, end of valve to base
of spring seat, 'C' = 44.163 to 45.288 mm
(1.741 to 1.802 in).
13.Check condition of valve springs. Valve
springs must be replaced as a complete
set.
lValve spring free length = 48.30 mm (1.90
in).
lValve spring fitted length = 40.40 mm (1.59
in).
l Spring load - valve closed = 339 ± 10 N (76
± 2.25 lbf).
lSpring load - valve open = 736 ± 10 N (166
± 2.25 lbf).
14.Check valve stem to guide clearance using the
following procedures:
15.Insert each valve into its respective guide.
16.Extend valve head approximately 13 mm (0.6
in) out of valve seat and position a DTI gauge
to rear of valve head.
17.Move valve towards front of cylinder head and
zero DTI gauge ensuring that stylus of gauge
remains in contact with valve head.
18.Move valve towards rear of cylinder head and
record gauge reading to give valve stem to
guide clearance.
l Valve stem to guide clearance 'D': Inlet =
0.025 to 0.066 mm (0.001 to 0.002 in).
l Valve stem to guide clearance 'D': Exhaust
– 4.0 litre engines up to engine nos. 55D
05677A; 56D 50787A; 97D 05504A = 0.038
to 0.078 mm (0.0015 to 0.003 in).
lValve stem to guide clearance 'D': Exhaust
– 4.0 litre engines from engine nos. 55D
05678A; 56D 50788A; 97D 05505A and all
4.6 litre engines = 0.048 to 0.088 mm
(0.0019 to 0.0035 in).
19.Renew valve guides as necessary. 20.Using valve guide remover tool LRT-12-037
press valve guide into combustion face side of
cylinder head.
21.Lubricate new valve guide with engine oil and
with tapered portion of guide leading, insert
guide from valve spring side of head.
Note: Service valve guides are 0.025 mm
(0.001 in) oversize on outside diameter to
ensure an interference fit.
22.Fully fit guide using tool LRT-12-039A and
distance piece tool LRT-12-208
lValve guide installed height 'A' = 15.00 mm
(0.590 in).
23.Ream valve guide to 8.70 mm (0.342 in).
Note: Service valve guides are supplied with an
internal diameter of 8.1 mm 0.025 mm (0.319 in).
24.Position cylinder head stands and mount
cylinder head on stands.
25.Check valve seat insert for pitting, burning,
cracks and wear. Replace as necessary.
Service valve seat inserts are available 0.025
mm (0.001 in) oversize on outside diameter to
ensure interference fit.

ENGINE - V8
OVERHAUL 12-2-69
9.Check overall dimensions of gudgeon pin.
Gudgeon pins are only supplied as an
assembly with replacement pistons.
lGudgeon pin length = 60.00 to 60.50 mm
(2.362 to 2.382 in).
lGudgeon pin diameter = 23.995 to 24.00
mm (0.9446 to 0.9448 in)
10.Measure cylinder bore wear and ovality in two
axis 40 to 50 mm (1.6 to 2 in) from top of bore.
The temperature of piston and cylinder
block must be the same to ensure accurate
measurement. Do not attempt to de-glaze
cylinder bores.
lGrade 'A' pistons: Cylinder bore = 94.00 to
94.015 mm (3.7007 to 3.7013 in).
lGrade 'B' pistons: Cylinder bore = 94.016 to
94.030 mm (3.7014 to 3.7019 in).
lMaximum ovality = 0.013 mm (0.0005 in).
11.Check alignment of connecting rods. Reassembly
1.Pistons have a 5 mm (0.2 in) offset gudgeon pin
which can be identified by an arrow mark on
the piston crown. This arrow must always point
towards the front of the engine.
2.Assemble pistons to connecting rods with
arrow on piston pointing towards domed
shaped boss on connecting rod for RH bank of
cylinders and arrow pointing away from domed
shaped boss for LH bank of cylinders.
3.Clamp hexagon body of tool LRT-12-013 in
vice.
4.Screw large nut back until flush with end of
centre screw.
5.Locate remover/replacer adapter LRT-12-126/
2 with its long spigot inside bore of hexagon
body.
6.Fit parallel sleeve, part of tool LRT-12-013,
ensuring that grooved end is towards open end
of tool LRT-12-013. Position sleeve up to
shoulder of centre screw.
7.Lubricate gudgeon pin and bores of connecting
rod and piston with graphite oil.
8.Locate connecting rod and piston to centre
screw with connecting rod entered on parallel
sleeve, part of LRT-12-013 up to the machined
groove on the sleeve.

ENGINE - V8
12-2-70 OVERHAUL
9.Fit gudgeon pin on to centre screw and into
piston bore up to connecting rod.
10.Fit remover/replacer bush LRT-12-126/1 with
flanged end towards gudgeon pin.
11.Screw the stop nut on to centre screw and
position piston against groove of tool LRT-12-
126/2.
CAUTION: Ensure that prongs of tool LRT-
12–126/2 remain in contact with piston and
do not contact gudgeon pin.
12.Lock the stop nut securely with the lockscrew.
13.Lubricate centre screw threads and thrust race
with graphite oil, screw large nut up to tool
LRT-12-013.
14.Set torque wrench to 16 Nm (12 lbf.ft) and using
socket on large nut, pull gudgeon pin in until
flange of remover/replacer bushLRT-12-126/1
is 0.40 mm (0.016 in), dimension 'A' from
face of piston. If torque is exceeded during this
procedure, fit of gudgeon pin to connecting rod
is not acceptable and components must be
replaced.
CAUTION: The centre screw and thrust race
must be kept well lubricated throughout the
operation.
15.Dismantle tool, remove piston and check no
damage has occurred during pressing and that
piston moves freely on gudgeon pin.
16.Remove compression rings, oil control rails
and expander from new piston.
17.Invert piston and with arrow pointing towards
rear of cylinder block, insert piston into cylinder
liner.
18.Position piston with bottom of skirt 30 mm (1.12
in) from top cylinder liner. 19.Using feeler gauges, measure and record
clearance between piston and left hand side of
cylinder- viewed from the front of cylinder
block.
lPiston to bore clearance = 0.020 to 0.045
mm (0.001 to 0.002 in).
20.Insert piston rings into cylinder bore, use the
piston to hold the rings square to bore and
check the ring gap.
l1st compression ring = 0.30 to 0.50 mm
(0.012 to 0.02 in).
l2nd compression ring = 0.40 to 0.65 mm
(0.016 to 0.026 in).
lOil control ring rails = 0.38 to 1.40 mm
(0.015 to 0.055 in).
21.Remove piston rings from bore.
22.Fit oil control ring rails and expander, ensuring
ends butt and do not overlap.
23.Fit 2nd compression ring marked 'TOP' with
marking uppermost in 2nd groove.
24.Fit 1st compression ring in first groove either
way round.
25.Check piston ring to groove clearance.
l1st compression ring = 0.05 to 0.10 mm
(0.002 to 0.004 in).
l2nd compression ring = 0.05 to 0.10 mm
(0.002 to 0.004 in).
26.Position oil control expander ring joint and ring
rail gaps all at one side, between gudgeon pin
and away from LH side of piston - viewed from
front of piston. Position the gaps in ring rails
approximately 25 mm (1.0 in) each side of
expander ring joint.
27.Position compression rings with gaps on
opposite side of piston between gudgeon pin
and RH side of piston - viewed from front of
piston.
28.Thoroughly clean cylinder bores.
29.Lubricate piston rings and gudgeon pin with
clean engine oil.
30.Lubricate cylinder bore with clean engine oil.

ENGINE - V8
OVERHAUL 12-2-71
31.Using LRT-12-204, compress piston rings.
32.Insert connecting rod and piston into its
respective cylinder bore, ensuring domed
shaped boss on connecting rod faces towards
front of engine on RH bank of cylinders and
towards rear on LH bank of cylinders.
33.Clean connecting rod journal and bearing cap.
34.Lubricate connecting rod journal and
connecting rod bearings. 35.Fit connecting rod bearings and connecting rod
bearing caps ensuring they are in their correct
fitted order.
NOTE: The rib on the edge of the bearing cap
must face towards the front of the engine on the
RH bank of cylinders and towards the rear on
the LH bank.
36.Fit bolts and tighten to 20 Nm (15 lbf.ft) then
turn a further 80°.
37.Fit oil pick-up strainer.

+ ENGINE - V8, OVERHAUL, Strainer
- oil pick-up.
38.Fit cylinder head gasket.

+ ENGINE - V8, OVERHAUL, Gasket -
cylinder head.

ENGINE - V8
12-2-72 OVERHAUL
Bearings - connecting rods
$% 12.17.16.01
Disassembly
1.Remove oil pick up strainer.

+ ENGINE - V8, OVERHAUL, Strainer
- oil pick-up.
2.Suitably mark cylinder reference number on
each connecting rod bearing cap.
3.Remove 2 bolts securing each connecting rod
bearing cap, remove caps and recover
connecting rod bearings.
CAUTION: Keep bearing caps, bearings and
bolts in their fitted order.
4.Push each connecting rod up cylinder bore
until connecting rods are clear of crankshaft
journals.
CAUTION: Ensure that connecting rods do
not contact cylinder bores.
5.Remove bearing shells from each connecting
rod. Inspect
1.Clean crankshaft journals and bearing
locations in connecting rods.
2.Inspect connecting rod bearings for wear and
renew if necessary. Connecting rod bearings
are available in two oversizes.
lConnecting rod bearing 1st oversize = 0.254
mm (0.01 in).
lConnecting rod bearing 2nd oversize =
0.508 mm (0.02 in).
3.Check crankshaft big-end journals for wear and
scoring. Measure for ovality; taking 3
measurements at 120° intervals at each end
and at centre of journals.
lStandard journal = 55.500 to 55.513 mm
(2.20 to 2.22 in).
l1st undersize journal - 0.254 mm (0.01 in) =
55.246 to 55.259 mm (2.17 to 2.18 in).
l2nd undersize journal - 0.508 mm (0.02 in)
= 54.992 to 55.005 mm (2.16 to 2.165 in).
lJournal - max. ovality = 0.040 mm (0.002 in)
Reassembly
1.Clean connecting rod caps.
2.Lubricate connecting rod journals and bearing
shells with clean engine oil.
3.Fit bearing shells to connecting rods and caps.
4.Rotate crankshaft until connecting rod journals
are correctly positioned.
5.Taking care not to displace bearing shells, pull
connecting rods on to crankshaft journals.
6.Check that bearing shells are correctly located
in connecting rod bearing caps.
7.Fit connecting rod bearing caps, ensuring that
they are in their correct fitted order.
NOTE: The rib on the edge of the bearing cap
must face towards the front of engine on the RH
bank of cylinders and towards the rear on the
LH bank.
8.Lightly oil threads of connecting rod bolts. Fit
connecting rod bolts and tighten to 20 Nm (15
lbf.ft) then turn a further 80°.

EMISSION CONTROL - V8
DESCRIPTION AND OPERATION 17-2-19
EVAP (charcoal) Canister
1EVAP canister
2Port to breather tube3Port – vent line from fuel tank
4Port – purge line
The EVAP canister is mounted on a bracket fitted beneath the vehicle on the RH side of the chassis. The EVAP
canister ports face towards the front of the vehicle. The EVAP canister has inscriptions next to each port for
identification of the 'purge', 'tank' and 'air' connections.
The purge line from the EVAP canister is connected to the back of the inlet manifold plenum, after the throttle body
via a purge valve. The pipe between the EVAP canister and the purge valve is routed over the transmission and into
the LH side of the engine bay. The pipe clips to the purge port on the EVAP canister by means of a straight quick-fit
connector and the connection is covered by a rubber seal which is held in position on the port stub pipe.
The vent line from the fuel tank to the EVAP canister connects to the vent port on the canister by means of an elbowed
quick-fit connector. The line passes along the chassis behind the EVAP canister and terminates in a straight female
quick-fit connector to the fuel vent line at the fuel filler.
The plastic pipe to the atmosphere vent line connects to the port on the EVAP canister by means of a short rubber
hose and metal band clips. The atmosphere end of the plastic pipe terminates in a quick fit connector to the pipe
leading to the CVS unit on NAS vehicles with vacuum type, EVAP system leak detection and two snorkel tubes
situated behind the engine at the bulkhead on ROW vehicles. The bore of the plastic breather pipe is larger on NAS
vehicles than on ROW vehicles.

EMISSION CONTROL - V8
DESCRIPTION AND OPERATION 17-2-33
Vacuum Reservoir
1Vacuum port to SAI vacuum solenoid valve
2Vacuum port to intake manifold
(one-way valve end)3Vacuum reservoir
A vacuum reservoir is included in the vacuum supply line between the intake manifold and the SAI vacuum solenoid
valve. The vacuum reservoir contains a one-way valve, to stop depression leaking back towards the intake manifold
side. The reservoir holds a constant vacuum so that the SAI control valves open instantaneously as soon as the SAI
solenoid valve is energised.
The vacuum reservoir is a plastic canister construction located on a bracket at the LH side of the engine compartment
on vehicles up to 2003 model year and on the RH side of the engine compartment, near the bulkhead, on vehicles
from 2003 model year. It is important to ensure the reservoir is fitted in the correct orientation, and the correct vacuum
hoses are attached to their corresponding ports. The one-way valve end of the vacuum reservoir (cap end, to inlet
manifold) is fitted towards the rear of the vehicle.
A small bore nylon hose is used to connect the one-way valve end of the vacuum reservoir to a port on the RH side
of the inlet manifold. A further hose connects between the other port on the vacuum reservoir and a port on the front
of the SAI vacuum solenoid valve.
M17 0212
1
2
3

ENGINE MANAGEMENT SYSTEM - V8
18-2-14 DESCRIPTION AND OPERATION
Crankshaft speed and Position (CKP) sensor (C0168)
The CKP sensor is located towards the rear of the engine below cylinder number 7, with its tip adjacent to the outer
circumference of the flywheel. The CKP sensor is the most important sensor on the vehicle and without its signal the
engine will not run. The signal produced by the CKP sensor allows the ECM to determine crankshaft angle and speed
of rotation. The ECM uses this information to calculate ignition timing and fuel injection timing.
The CKP sensor works as a variable reluctance sensor. It uses an electromagnet and a reluctor ring to generate a
signal. As the reluctor ring passes the tip of the CKP sensor the magnetic field produced by the sensor is cut and then
re-instated. The ECM measures the signal as an ac voltage.
The output voltage varies in proportion to engine speed. The reluctor ring has a set tooth pattern, 60 teeth are spaced
at 6° intervals and are 3° wide, two teeth are removed to provide a reference mark at 60° BTDC for number 1 cylinder.
There is no back up strategy or limp home facility if this sensor fails, the engine does not run.
Input/Output
Because of the nature of its operation the CKP sensor does not require any electrical input source. The CKP sensor
is a 3 pin variable reluctance sensor generating its own electrical output. The 2 output sources from the sensor are
earthed via pin 46 of connector C0636 of the ECM and sensor output is via pin 32 of connector C0636 of the ECM.
This output is in the form of an ac voltage waveform. The 3rd pin is used by the ECM as an earth screen, this screen
protects the integrity of the CKP sensor signal to ensure that outside electrical interference is eliminated, it is
controlled via pin 45 of connector C0636 of the ECM. The ac voltage generated from the CKP sensor is relative to
engine speed.