1999 LAND ROVER DISCOVERY check engine

ENGINE - V8
12-2-62 OVERHAUL
10.Remove cylinder head gasket.
CAUTION: Support both ends of cylinder
head on blocks of wood.
Inspect
1.Clean mating faces of cylinder block and head
using suitable gasket removal spray and a
plastic scraper, ensure that bolt holes in block
are clean and dry.
CAUTION: Do not use a metal scraper or
machined surfaces may be damaged.
2.Check head and block faces for warping and
pitting.
lMaximum cylinder head warp = 0.05 mm
(0.002 in).
Note: Cylinder head can be refaced to 0.50
mm (0.02 in) maximum below head height –
See cylinder head overhaul.
3. Models with SAI: Using a 5/8 in x 20 TPI (
threads per inch) UNF tap having a class 2A
thread, remove deposits from secondary air
injection adapter tappings in cylinder head.
CAUTION: Ensure that tap used has 20 TPI.Reassembly
1.Ensure that cylinder head bolt holes are clean
and dry.
2.Fit cylinder head gasket with the word TOP
uppermost.
CAUTION: Gaskets must be fitted dry.
3.Carefully fit cylinder head and locate on
dowels.
4.Lightly lubricate new cylinder head bolt threads
with clean engine oil.
5.Noting that bolts 1, 3 and 5 are longer than the
remainder, fit bolts and tighten in the sequence
shown to 20 Nm (15 lbf.ft) then turn through 90
°, then a further 90 °. CAUTION: Do not
tighten bolts 180° in one operation.
6. Models with SAI: Fit new air injection adapters
and using a 9 mm hexagonal drive bit, tighten
to 33 Nm (24 lbf.ft).
CAUTION: Do not use an air tool to tighten
adapters.
7.Clean the push rods, Lubricate ends of push
rods with clean engine oil, and fit in their
removed order.
8.Clean bases of rocker pillars and mating faces
on cylinder head.
9.Clean contact surfaces on rockers, valves and
push rods.
10.Lubricate contact surfaces and rocker shaft
with clean engine oil.
11.Fit rocker shaft assembly and engage push
rods.
12.Fit rocker shaft bolts and progressively tighten
to 40 Nm (30 lbf.ft).
13.Connect ht leads to spark plugs in their correct
fitted order.
14. RH cylinder head: Position alternator
mounting bracket, fit bolts and tighten to 40 Nm
(30 lbf.ft).
15. RH cylinder head: Fit auxiliary drive belt
tensioner.
16.Fit inlet manifold gasket.

+ ENGINE - V8, OVERHAUL, Gasket -
inlet manifold.

ENGINE - V8
OVERHAUL 12-2-63
Cylinder head - overhaul
$% 12.29.19.01
Disassembly
1.Remove cylinder head gasket.

+ ENGINE - V8, OVERHAUL, Gasket -
cylinder head.
2.Loosen screw on tool LRT-12-034.
3.Fit tool LRT-12-034 to valve and tighten screw
to compress valve spring sufficiently to release
collets from valve spring cap.
4.Remove 2 collets and release valve spring
compressor.
5.Remove valve spring cap and valve spring.
6.Remove valve from cylinder head.
7.Remove and discard valve stem oil seal.
8.Repeat above operations for remaining valves.
9.Keep valves, springs, caps and collets in their
fitted order. Inspect
1.Clean mating faces of cylinder block and head
using suitable gasket removal spray and a
plastic scraper, ensure that bolt holes in block
are clean and dry.
CAUTION: Do not use a metal scraper or
machined surfaces may be damaged.
2.Clean cylinder head, valve springs, valves and
inlet valve guide bores. Ensure all loose
particles of carbon are removed on completion.
3. Models with SAI: Using a 5/8 in x 20 TPI (
threads per inch) UNF tap having a class 2A
thread, remove deposits from secondary air
injection adapter tappings in cylinder head.
CAUTION: Ensure that tap used has 20 TPI.
4.Check head and block faces for warping and
pitting. Maximum warp = 0.05 mm (0.002 in).
5.Check cylinder head height at each end of
head. Renew a head which is outside limits.
a22.94 mm (0.903 in) - New
b62.56 mm (2.463 in) - New

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
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
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.