1999 LAND ROVER DISCOVERY oil pressure

ENGINE - V8
DESCRIPTION AND OPERATION 12-2-9
Oil is drawn from the sump through a strainer and into the oil pump via the oil pick-up pipe. Pressurised oil from the
pump passes through the oil cooler (if fitted) mounted in front of the radiator and returns to the full flow oil filter
element. Oil from the filter passes into the main oil gallery and through internal drillings to the crankshaft where it is
directed to each main bearing and to the big-end bearings via numbers 1, 3 and 5 main bearings. An internal drilling
in the cylinder block directs oil to the camshaft where it passes through further internal drillings to the hydraulic
tappets, camshaft bearing journals and rocker shafts. Lubrication to the pistons, small ends and cylinder bores is by
oil grooves machined in the connecting rods and by splash.
Oil pressure switch
The oil pressure warning light switch registers low oil pressure in the main oil gallery on the outflow side of the filter.
Whilst the engine is running and oil pressure is correct, the switch is open. When the ignition is switched on or if oil
pressure drops below the pressure setting of the switch, the switch closes and the low oil pressure warning lamp
located in the instrument pack will illuminate.
Hydraulic tappets
1Clip
2Pushrod seat
3Inner sleeve
4Upper chamber5Non-return ball valve
6Spring
7Outer sleeve
8Lower chamber
The hydraulic tappet provides maintenance free, quiet operation of the valves. This is achieved by utilizing engine oil
pressure to eliminate the clearance between the rocker arms and valve stems. When the valve is closed, engine oil
pressure present in the upper chamber, passes through the non-return ball valve and into the lower chamber. When
the cam begins to lift the outer sleeve, the resistance of the valve spring, felt through the push rod and seat, causes
the tappet inner sleeve to move downwards inside the outer sleeve. This downwards movement closes the non-return
ball valve and increases the pressure in the lower chamber sufficiently to ensure that the valve is fully opened by the
push rod. As the tappet moves off the peak of the cam, the non-return ball valve opens thereby allowing the pressure
in both chambers to equalize. This ensures that the valve will be fully closed when the tappet is on the back of the
cam.
Crankcase ventilation
A positive crankcase ventilation system is used to vent crankcase gases to the air induction system. Gases are drawn
from the left hand rocker cover to a tapping in the throttle body. An oil separator is incorporated in the hose connection
stub pipe in the right hand rocker cover, gases from this connection are drawn to a tapping in the inlet manifold.

+ EMISSION CONTROL - V8, DESCRIPTION AND OPERATION, Crankcase Emission Control System.

ENGINE - V8
ADJUSTMENTS 12-2-11
ADJUST ME NTS
Engine oil pressure check
$% 12.90.09.01
Check
1.Remove oil pressure switch.

+ ENGINE - V8, REPAIRS, Switch - oil
pressure.
2.Connect pressure check kit LRT-12-052C
adaptor and gauge to oil pressure switch
position on timing gear cover.
3.Check and if necessary top up engine oil.
4.Run engine at idle speed and check that oil
pressure is within limits given.

+ GENERAL DATA, Engine - V8.
5.Switch off ignition.
6.Remove pressure check kit LRT-12-052C.
7.Clean oil spillage.
8.Fit oil pressure switch.

+ ENGINE - V8, REPAIRS, Switch - oil
pressure.
Adjust
1.If engine oil pressure is below figures given,
check condition of oil pump and/or main and
big end bearings.

ENGINE - V8
REPAIRS 12-2-27
11.Remove bolt securing oil cooling pipes to PAS
pump housing and remove saddle clamp.
12.Release PAS pump high and low pressure
pipes and position aside.
CAUTION: Always fit plugs to open
connections to prevent contamination.
13.Release clips securing hose to coolant pump
and coolant rail, release hose and position
aside.
14.Release 2 harness clips from coolant rail.
15.Remove bolt securing coolant rail and position
rail aside. 16.Remove bolt securing engine earth lead and
position earth lead aside.
17.Remove nut securing engine harness positive
lead to battery, release lead and position
aside.
18.Release clips and remove fuse box cover.
19.Remove bolt securing starter lead to fuse box,
release lead and position aside.
20.Disconnect 2 engine harness multiplugs from
fuse box.

ENGINE - V8
12-2-30 REPAIRS
Refit
1.Clean mating faces of engine and gearbox,
dowel and dowel holes.
2.Lubricate splines and bearing surface on first
motion shaft with grease.
3.With assistance position engine in engine bay,
align to gearbox and locate on dowels.
4.Position support brackets, fit bell housing bolts
and tighten to 50 Nm (37 lbf.ft).
5.Position engine mountings, fit nuts and tighten
to 85 Nm (63 lbf.ft).
6.Lower lifting equipment and remove from
engine.
7. Models with automatic gearbox: Align torque
converter to drive plate, fit bolts and tighten to
50 Nm (37 lbf.ft). Fit access plug.
8.Fit exhaust front pipe.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Front pipe.
9.Position oil cooling pipe saddle clamps and
tighten bolts.
10.Position engine harness into foot well.
11.Connect 5 multiplugs to ECM.
12.Fit toe board and secure with trim fixings.
13.Connect engine harness earth to body and
secure with nut.
14.Connect engine harness to main harness
multiplug.
15.Connect multiplug to EVAP purge valve.
16.Connect engine harness multiplugs to fuse
box.
17.Connect starter lead to fuse box and secure
with nut.
18.Connect engine harness positive lead to
battery and tighten nut.
19.Fit fuse box cover.
20.Position engine earth lead and secure with
bolt.
21.Position coolant rail and secure with bolt.
22.Connect harness clips to coolant rail.
23.Connect hose to coolant rail and coolant pump
and secure with clips.
24.Connect PAS pump high and low pressure
pipes and secure with clips.
25.Position oil cooling pipe saddle clamp to PAS
pump housing and secure with bolt.
26.Clean A/C compressor and housing mating
faces, dowels and dowel holes.
27.Position A/C compressor, fit bolts and tighten
to 22 Nm (16 lbf.ft).
28.Connect multiplug to A/C compressor.
29.Clean ACE pump and housing mating faces,
dowels and dowel holes.
30.Position ACE pump, fit bolts and tighten to 22
Nm (16 lbf.ft). 31.Clean all pulley 'V's, fit auxiliary drive belt,
using a 15mm spanner, release belt tensioner
secure belt and re-tension drive belt .
32.Ensure auxiliary drive belt is correctly located
on all pulleys.
33.Fit radiator.

+ COOLING SYSTEM - V8, REPAIRS,
Radiator.
34.Fit top hose and secure with clips.
35.Connect fuel pipe to fuel rail.
36.Position ignition coils and connect ht leads.
37.Fit upper inlet manifold.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Gasket - inlet
manifold - upper - Without Secondary Air
Injection.
38.Fit new oil filter and refill engine with oil.

+ ENGINE - V8, REPAIRS, Filter - oil.

+ MAINTENANCE, PROCEDURES,
Engine oil - V8 engine.
39.Top up gearbox oil.

+ MAINTENANCE, PROCEDURES,
Automatic gearbox.

ENGINE - V8
12-2-36 REPAIRS
Pump - oil
$% 12.60.26
Remove
1.Remove timing gear cover gasket.

+ ENGINE - V8, REPAIRS, Gasket -
timing gear cover.
2.Remove bolt securing CMP sensor, remove
clamp and sensor.
3.Remove 6 bolts securing coolant pump,
remove pump and discard gasket.
4.Remove oil pressure switch and discard
sealing washer.
5.Remove 4 bolts securing oil filter head, remove
filter head and discard 2 'O' rings.
6.Remove filter head adaptor. Refit
1.Ensure filter head adaptor is clean.
2.Fit filter head adaptor and tighten bolts to 13
Nm (9 lbf.ft).
3.Clean filter head and mating face.
4.Fit new 'O' rings to filter head and filter head
adaptor.
5.Fit filter head and tighten bolts to 8 Nm (6 lbf.ft).
6.Ensure oil pressure switch and mating face is
clean.
7.Fit new sealing washer and tighten switch to 15
Nm (11 lbf.ft).
8.Clean coolant pump and mating face.
9.Use a new gasket and fit coolant pump.
Tighten bolts securing coolant pump to 25 Nm
(19 lbf.ft).
10.Ensure CMP sensor is clean and fit sensor to
cover.
11.Fit clamp to CMP sensor and tighten bolt to 8
Nm (6 lbf.ft).
12.Fit timing gear cover gasket.

+ ENGINE - V8, REPAIRS, Gasket -
timing gear cover.

ENGINE - V8
REPAIRS 12-2-39
Switch - oil pressure
$% 12.60.50
Remove
1.Release fixings and remove battery cover.
2.Disconnect battery earth lead.
3.Raise front of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
4.Remove fixings and remove underbelly panel.
5.Disconnect multiplug from oil pressure switch.
6.Position container below switch to catch oil
spillage.
7.Remove oil pressure switch and discard
sealing washer.
Refit
1.Clean oil pressure switch threads.
2.Fit new sealing washer to switch.
3.Fit oil pressure switch and tighten to 15 Nm (11
lbf.ft) .
4.Connect multiplug to oil pressure switch.
5.Fit underbelly panel and secure with fixings.
6.Remove stand(s) and lower vehicle.
7.Connect battery earth lead.
8.Fit battery cover and retain with fixings.
9.Top up engine oil.
Cooler - engine oil
$% 12.60.68
Remove
1.Release fixings and remove battery cover.
2.Release fixings and remove cooling fan cowl.
3.Remove front grille.

+ EXTERIOR FITTINGS, REPAIRS,
Grille - front - up to 03MY.
4.Remove 6 scrivets and remove LH and RH air
deflectors from front panel.
5.Remove nut and move LH horn aside.

ENGINE - V8
REPAIRS 12-2-41
Gasket - timing gear cover
$% 12.65.04
Remove
1.Remove oil pick-up strainer.

+ ENGINE - V8, REPAIRS, Strainer -
oil pick-up.
2.Remove timing gear cover oil seal.

+ ENGINE - V8, REPAIRS, Seal - cover
- timing gears.
3.Remove engine oil filter.

+ ENGINE - V8, REPAIRS, Filter - oil.
4.Remove and discard 3 bolts securing coolant
pump pulley and remove pulley.
5.Remove 3 bolts securing PAS pump pulley and
remove pulley.
6.Drain cooling system.

+ COOLING SYSTEM - V8,
ADJUSTMENTS, Drain and refill.7.Release clip and disconnect coolant hose from
coolant pump.
8.Disconnect multiplug from oil pressure switch.
9.Disconnect multiplug from CMP sensor.
10. If fitted: Loosen union and disconnect oil
cooler pipe from timing gear cover. Remove
and discard 'O' ring.
CAUTION: Always fit plugs to open
connections to prevent contamination.
11.Remove 9 bolts securing timing gear cover and
remove cover. Remove and discard gasket.

ENGINE - V8
12-2-42 REPAIRS
Refit
1.Clean mating faces of timing gear cover and
cylinder block. Clean dowels and dowel holes.
Ensure bolt holes are clean and dry, remove all
traces of sealant from bolt threads.
2.Fit new gasket, dry, to dowels in cylinder block.
3.Locate tool LRT-12-090 on timing cover and oil
pump drive gear.
4.Position timing cover to cylinder block and at
the same time, rotate tool LRT-12-090 until
drive gear keyway is aligned with Woodruff key.
5.Remove tool LRT-12-090.
6.Apply sealant, Part Number STC 50552 to
threads of timing cover bolts, fit bolts and
working in the sequence illustrated, tighten to
22 Nm (17 lbf.ft) . Ensure CMP sensor multiplug
bracket is secured by bolt.
7. If fitted: Fit new 'O' ring to oil cooler pipe,
connect pipe to timing gear cover and tighten
union to 15 Nm (11 lbf.ft).
8.Connect multiplug to oil pressure switch.
9.Connect multiplug to CMP sensor. 10.Connect coolant hose to coolant pump and
secure with clip.
11.Ensure mating faces of PAS pump pulley and
drive flange are clean, fit pulley and tighten
bolts to 22 Nm (16 lbf.ft).
12.Remove all traces of thread locking material
from coolant pump pulley drive flange bolt
holes using an M8 tap.
13.Ensure mating faces of coolant pump pulley
and drive flange are clean, fit pulley and tighten
new Patchlok bolts to 22 Nm (16 lbf.ft).
14.Ensure mating faces of oil filter and adaptor are
clean, smear clean engine oil onto seal and fit
filter.
15.Fit timing gear cover oil seal.

+ ENGINE - V8, REPAIRS, Seal - cover
- timing gears.
16.Fit oil pick-up strainer.

+ ENGINE - V8, REPAIRS, Strainer -
oil pick-up.
17.Refill cooling system.

+ COOLING SYSTEM - V8,
ADJUSTMENTS, Drain and refill.