1999 LAND ROVER DISCOVERY ECU

ENGINE - V8
12-2-60 OVERHAUL
3.Remove and discard rocker cover gaskets.
4.Progressively remove 4 bolts securing rocker
shaft assembly to cylinder head, release
rocker shaft from push rods and remove rocker
shaft.
5.Ensure push rods remain located in tappets
when rocker shaft is removed. Retain all
components in their removed sequence for
re-assembly.
6.Remove and discard split pin from one end of
rocker shaft.
7.Collect plain and wave washers.
8.Remove the rocker arms, rocker pillars and
springs.
9.Remove and discard remaining split pin and
collect plain and wave washers. Inspect
1.Clean all components.
2.Inspect rocker shaft and rocker arms for wear
and scoring. Replace as required.
3.Replace weak or broken springs.
4.Lubricate moving parts with clean engine oil.
Reassembly
1.Reassemble rocker shafts, ensuring that
components are returned to their original
positions, secure plain washers with new split
pins.
2.Ensure shaft identification groove is positioned
at one o'clock, with push rod locations of rocker
arms to the right. Oil feed restriction will
result if rocker shafts are incorrectly
assembled.
3.Ensure that rocker shaft bolt holes are clean
and dry.
4.Position rocker shaft assembly to cylinder
head ensuring push rods are engaged in
rocker arms.
5.Fit rocker shaft bolts and progressively tighten
to 40 Nm (30 lbf.ft).
6.Clean mating faces of rocker cover and cylinder
head, ensure that bolt holes are clean and dry.
7.Fit new rocker cover gasket, dry, position
rocker cover, ensuring that gasket is correctly
located.
8.Fit new, 'patched' multi-hex bolts ensuring that
2 short bolts are on side of rocker cover nearest
centre of engine.
9.Tighten bolts by diagonal selection to:
lStage 1 - 3 Nm (2.5 lbf.ft)
lStage 2 - 8 Nm (6 lbf.ft)
10.Ensure that gasket is correctly positioned
around periphery of rocker cover.
11.Secure ht leads to rocker cover.

ENGINE - V8
OVERHAUL 12-2-61
Gasket - cylinder head
$% 12.29.02.01
Disassembly
1.Remove inlet manifold gasket.

+ ENGINE - V8, OVERHAUL, Gasket -
inlet manifold.
2. RH cylinder head: Remove auxiliary drive belt
tensioner.
3. RH cylinder head: Remove bolts securing
alternator mounting bracket and remove
bracket.
4.Noting their fitted order, disconnect ht leads
from spark plugs.
5.Progressively remove 4 bolts securing the
rocker shaft and remove rocker shaft.
6.Remove push rods and store in their fitted
order. 7. Models with SAI: Using a 9 mm hexagonal
drive bit, remove 2 air injection adapters from
cylinder head; discard adapters.
To release the adapter thread locking agent
and prevent damage to the cylinder head,
remove the adapters by alternately loosening
then tightening slightly. Repeat this procedure
until adapters are removed.
CAUTION: Do not use air tools to remove
adapters.
8.Working in the sequence shown remove 10
bolts securing the cylinder head to block.
Discard the bolts.
9.Remove cylinder head.

ENGINE - V8
12-2-66 OVERHAUL
26.Remove worn valve seat.
CAUTION: Take care not to damage the
counterbore in the cylinder head when
removing valve seats.
27.Heat cylinder head evenly to approximately
120° C (250°F).
WARNING: Handle the hot cylinder head
with care.
28.Using a suitable mandrel, press new insert fully
into counterbore.
29.Allow cylinder head to air cool.
CAUTION: Renew worn valve guides and/or
valve seats before lapping the valves.
30.Recut valve seat in head and lap in valves
using fine paste.
31.Coat valve with a small quantity of engineer's
blue, insert valve and press into position
several times without rotating. Seating position
should be in centre of valve face. 32.Check valve installed height if valve seats have
been refaced or renewed.
lValve installed height, end of valve to base
of spring seat, 'A' = 44.16 to 45.29 mm (1.74
to 1.80 in).
33.Reface valves as necessary. If a valve has to
be ground to a knife-edge to obtain a true seat,
renew valve.
34.Cut valve seats using suitable cutters:
lValve seat angle 'A' = 45°.
lValve seat insert diameter 'B' Inlet = 36.83
mm (1.45 in).
lValve seat insert diameter 'B' Exhaust =
31.50 mm (1.24 in).
lSeating width 'C' - Inlet = 0.89 to 1.4 mm
(0.035 to 0.055 in).
lSeating width 'C' - Exhaust = 1.32 to 1.83
mm (0.052 to 0.072 in).
lAngle 'D' = 70° .
lAngle 'E' = 46° to 46° 25'.
lAngle 'F' = 20° .

ENGINE - V8
OVERHAUL 12-2-67
35. Check that cutter blades are adjusted so that
middle of blade contacts area of material to be
cut. Use light pressure and only remove the
minimum of material necessary.
36.Clean valve seat and valve.
Reassembly
1.Clean spring caps, collets and valve springs.
2.Lubricate new valve stem oil seal with clean
engine oil and fit seal.
3.Lubricate valve with clean engine oil and fit
valve.
4.Fit spring and cap, compress spring using tool
LRT-12-034 and fit collets.
5.Release valve spring and remove tool LRT-12-
034.
6.Fit cylinder head gasket.

+ ENGINE - V8, OVERHAUL, Gasket -
cylinder head.
Piston assemblies
$% 12.17.02.01
Disassembly
1.Remove cylinder head.

+ ENGINE - V8, OVERHAUL, Gasket -
cylinder head.
2.Remove oil pick-up strainer.

+ ENGINE - V8, OVERHAUL, Strainer
- oil pick-up.
3.Suitably identify each connecting rod and
piston assembly to its respective cylinder bore.
4.Remove 2 bolts securing each connecting rod
bearing cap.
5.Remove connecting rod bearing cap and
collect connecting rod bearings.
6.Remove ridge of carbon from top of cylinder
bores.
7.Carefully push each piston assembly from the
top of the cylinder.
CAUTION: Ensure that connecting rods do
not contact cylinder bores.
8.Refit bearing cap onto connecting rod, lightly
tighten dowel bolts.
9.Suitably identify each piston to its respective
connecting rod.

ENGINE - V8
12-2-68 OVERHAUL
10.Position body of tool LRT-12-013 in vice.
11.Screw large nut back until flush with end of
centre screw.
12.Push centre screw forward until nut contacts
thrust race.
13.Position remover/replacer LRT-12-126/2 in
LRT-12-013 with its long spigot inside bore of
hexagon body.
14.Locate piston and connecting rod assembly on
centre screw and up to remover/replacer
adapter tool LRT-12-126/2.
CAUTION: Ensure that prongs of remover/
replacer adapter LRT-12-162/2 remain in
contact with piston and do not contact
gudgeon pin.
15.Fit remover/replacer bush LRT-12-126/1 on
centre screw with flanged end facing away from
gudgeon pin.
CAUTION: Ensure that remover/replacer
bush LRT-12-126/1 is correctly located in
gudgeon pin bore of piston.
16.Screw stop nut onto centre screw.
17.Lock the stop nut securely with the lock screw.
18.Push connecting rod to locate end of gudgeon
pin in remover/replacer adapter LRT-12-126/2.
19.Ensure remover/replacer bush LRT-12-126/1
is located in gudgeon pin bore of piston.
20.Screw large nut up to tool LRT-12-013.
21.Hold lock screw and turn large nut until
gudgeon pin is withdrawn from piston.
CAUTION: Ensure that prongs of tool LRT-
12–126/2 remain in contact with piston and
do not contact the gudgeon pin.
22.Dismantle tool LRT-12-013 and remove piston,
connecting rod and gudgeon pin. Inspect
1.Clean carbon from piston. Inspect piston for
distortion, cracks and burning.
2.Remove piston rings from piston.
3.Measure and record piston diameter at 90° to
gudgeon pin axis and 10 mm (0.4 in) from
bottom of the skirt. The piston must be 0.015 to
0.045 mm (0.001 to 0.002 in) smaller than the
cylinder bore.
4.Check gudgeon pin bore in piston for signs of
wear and overheating.
5.Pistons fitted on production are graded 'A' or
'B', the grade letter is stamped on the piston
crown.
lPiston diameter: Grade 'A' = 93.970 to
93.985 mm (3.6996 to 3.7002 in).
lPiston diameter: Grade 'B' = 93.986 to 94.00
mm (3.7002 to 3.7007 in).
6.Worn cylinders fitted with grade 'A' pistons may
be honed to accept the grade 'B' piston
provided that specified cylinder bore and
ovality limits are maintained. Grade 'B'
pistons are supplied as service
replacements. Do not attempt to de-glaze
cylinder bores.
CAUTION: Ensure replacement pistons are
correct for the compression ratio of the
engine. The compression ratio will be found
on the cylinder block adjacent to the engine
serial number.
7.Check gudgeon pins for signs of wear and
overheating.
8.Check clearance of gudgeon pin in piston.
l Gudgeon pin to piston clearance = 0.006 to
0.015 mm (0.0002 to 0.0006 in).

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
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°.

ENGINE - V8
OVERHAUL 12-2-73
9.Check clearance between connecting rods on
each crankshaft journal.
l Connecting rod clearance = 0.15 to 0.36
mm (0.006 to 0.014 in).
10.Fit oil pick up strainer.

+ ENGINE - V8, OVERHAUL, Strainer
- oil pick-up.
Crankshaft and main bearings
$% 12.21.33.01
Disassembly
1.Remove crankshaft rear oil seal.

+ ENGINE - V8, OVERHAUL, Seal -
crankshaft - rear - automatic models.
2.Remove timing gear cover gasket.

+ ENGINE - V8, OVERHAUL, Gasket -
timing gear cover.
3.Remove bolt securing camshaft gear.
4.Remove timing chain and gears.
5.Remove connecting rod bearings.

+ ENGINE - V8, OVERHAUL, Bearings
- connecting rods.