Engine & identification
Vehicle identification
| No. of cylinders Type | 8/OHV |
|---|---|
| Capacity (Fiscal) cc | 3950 (3914) |
| Compression ratio :1 | 9,35 |
| Suitable for unleaded petrol | Yes |
| Minimum octane rating RON | 95 |
| Ignition system Type | TSZ-i |
| Ignition system Description | Trans-i |
| Trigger location | Distributor |
| Fuel system Make | Lucas |
| Fuel system Type | 14 CUX |
| Fuel system Description | MFI-i |
| Air metering Type | Mass |
| Combined ignition and fuel ECM | No |
| Diagnostic socket | Yes |
Ignition system
| Ignition coil Make | Bosch |
|---|---|
| Ignition coil Type | 0 221 122 392 |
| Ignition coil supply voltage + with ballast V | 11,0 |
| Primary resistance Ohm | 0,67-0,82 |
| Distributor (ECM) Make | Lucas |
| Distributor (ECM) No. | 42583A |
| Contact breaker gap/trigger air gap mm | 0,20-0,35 |
Firing order
The firing order for the Land Rover Discovery 3.9 (1994–1998) is 1-8-4-3-6-5-7-2.
| Firing order | 1-8-4-3-6-5-7-2 |
|---|
Valve clearances
Valve clearances on the Land Rover Discovery 3.9 (1994–1998) are hydraulic — they self-adjust, so no manual clearance figure applies.
| Valve clearance - INLET mm | Hydraulic |
|---|---|
| Valve clearance - EXHAUST mm | Hydraulic |
Engine oil & fluids
Engine oil
The Land Rover Discovery 3.9 (1994–1998) takes 6.6 litres of engine oil with the filter.
A listed engine oil option is SAE 5W-30 for cold climates, with API/ACEA classification SJ/A2.
A listed engine oil option is SAE 10W-40 for moderate climates, with API/ACEA classification SJ/A2.
A listed engine oil option is SAE 15W-40 as an alternative for moderate climates, with API/ACEA classification SJ/A2.
A listed engine oil option is SAE 20W-50 for hot climates, with API/ACEA classification SJ/A2.
Manual gearbox
The manual gearbox has a listed capacity of 2.7 litres. The specified oil is ATF-G.
Transfer box
The transfer box has a listed capacity of 2.3 litres. The specified oil is SAE 90W.
Coolant
The listed total cooling-system capacity is 11.4 litres.
Grades, filling conditions and capacities
| Engine oil options | |
|---|---|
| Ambient temperature range | Cold climate |
| Engine oil grade SAE | 5W-30 |
| Engine oil classification API/ACEA | SJ/A2 |
| Ambient temperature range | Moderate climate |
| Engine oil grade SAE | 10W-40 |
| Engine oil classification API/ACEA | SJ/A2 |
| Ambient temperature range | Moderate climate alternative |
| Engine oil grade SAE | 15W-40 |
| Engine oil classification API/ACEA | SJ/A2 |
| Ambient temperature range | Hot climate |
| Engine oil grade SAE | 20W-50 |
| Engine oil classification API/ACEA | SJ/A2 |
| Engine with filter(s) litres | 6.6 |
| Other lubricants and capacities | |
| Manual transmission oil grade SAE | ATF-G |
| Manual transmission litres | 2.7 |
| Automatic transmission fluid Type | Dexron IID |
| Automatic transmission (dry fill) litres | 9.1 |
| Differential front/AT litres | 1.7 |
| Differential oil grade - rear SAE | 90W |
| Differential rear litres | 1.7 |
| Transfer box oil grade SAE | 90W |
| Transfer box litres | 2.3 |
| Cooling system - total capacity litres | 11.4 |
| Brake fluid Type | DOT 4 |
| Power steering fluid Type | Dexron II |
| Power steering fluid litres | 3.4 |
Brakes & wear limits
Brake disc thickness
Brake discs on the Land Rover Discovery 3.9 (1994–1998) are replaced at a minimum thickness of 12 mm (solid) front and 11,7 mm rear.
| Minimum disc thickness for replacement - solid Front | 12 mm |
|---|---|
| Minimum disc thickness for replacement Rear | 11,7 mm |
Brake disc and drum dimensions
| Minimum pad thickness Front | 2 mm |
|---|---|
| Minimum pad thickness Rear | 2 mm |
| Parking brake travel No. of notches | 3-4 |
Bar lengths use a square-root scale so small and large values stay readable.
Service & electrical
Ignition timing
Basic ignition timing for the Land Rover Discovery 3.9 (1994–1998) is 5°±1° BTDC at 800 rpm.
| Ignition timing | Without vacuum |
|---|---|
| Ignition timing - basic BTDC °Engine/rpm | 5±1/800 |
Battery
The Land Rover Discovery 3.9 (1994–1998) uses a 12 V, 60 Ah battery (reserve capacity 90 minutes).
| Battery V/RC(Ah) | 12/90 (60) |
|---|
Spark plugs
The Land Rover Discovery 3.9 (1994–1998) uses Champion RN11YC spark plugs with a 0,6 mm electrode gap.
| Spark plugs Original equipment | Champion |
|---|---|
| Spark plug Type | RN11YC |
| Electrode gap mm | 0,6 |
| Spark plugs Make | Autolite |
| Spark plug Type | APP64 |
| Electrode gap mm | 0,8 |
| Spark plugs Make | Beru |
| Spark plug Type | 14R-8DU |
| Electrode gap mm | 0,8 |
| Spark plugs Make | Champion |
| Spark plug Type | RN11YC |
| Electrode gap mm | 0,6 |
| Spark plugs Make | NGK |
| Spark plug Type | BPR6E-VG |
| Electrode gap mm | 0,9 |
Tuning and emissions
| Ignition advance | Without vacuum and basic timing |
|---|---|
| Ignition advance checks °Engine/rpm | 4-8/1600 |
| Ignition advance checks °Engine/rpm | 13-17/2800 |
| Ignition advance checks °Engine/rpm | 11-17/4400 |
| Idle speed rpm | 700±30 Not adjustable |
| Idle speed - alternative rpm | AT=600±30 Not adjustable |
| Oil temperature °C | 70 |
| CO level at idle speed - tailpipe Vol. % CO | 0,5 Max Not adjustable |
| HC level at idle speed ppm | 100 |
| CO2 level at idle speed Vol. % CO2 | 14,5-16 |
| O2 level at idle speed Vol. % O2 | 0,1-0,5 |
| Increased idle speed for CO test rpm | 2500-2800 |
| CO content at increased idle speed Vol. % | 0,3 |
| Lambda at increased idle λ | 0,98-1,02 |
Starting and charging
| Starter motor Make | Bosch |
|---|---|
| Starter motor Type | 0 001 362 092 |
| Maximum cranking amps A | 162-198 |
| Alternator Make | Marelli |
| Alternator Type | A133-100A |
| Alternator output A/V/rpm | 100/14/6000 |
| Voltage regulator Type | 15TR |
| Regulated voltage V | 13,6-14,4 |
Service checks and adjustments
| Compression pressure bar | 11,5-12,2 |
|---|---|
| Oil pressure bar/rpm | 2,1-2,8/2400 |
| Radiator cap bar | 1,00 |
| Thermostat opens °C | 82 |
Fuel system
| System pressure bar | 2,9-3,2 |
|---|---|
| Regulated pressure with vacuum bar | 2,4-2,6 |
| Engine coolant temperature (ECT) sensor Ohm/°C | 300-400/80 |
| Injector Ohm | 16,0-17,0 |
| Idle air control (IAC) valve/idle speed control (ISC) actuator Ohm | 40,0-60,0 |
| Lambda sensor (Oxygen) heater Ohm | 2,5-6,0 |
Tightening torques
Cylinder head bolt torque
The cylinder head bolts on the Land Rover Discovery 3.9 (1994–1998) are tightened in 3 stages: 20 Nm, then 90°, then a final 90°.
| Cylinder head | |
|---|---|
| Renew bolts | No |
| Tighten | 20 Nm |
| Tighten | 90° |
| Tighten | 90° |
| Cylinder head instructions | — | |
|---|---|---|
| Other engine tightening torques | ||
| Oil pump to cylinder block | 15 Nm | |
| Sump bolts | 18 Nm | |
| Sump drain bolt | 40 Nm | |
| Flywheel/driveplate | 80 Nm | |
| Clutch pressure plate | 28 Nm | |
| Crankshaft pulley/damper centre bolt | 280 Nm | |
| Camshaft sprocket/gear | 65 Nm | |
| Camshaft/rocker cover | 10 Nm | |
| Inlet manifold to cylinder head | 25 Nm | |
| Exhaust manifold to cylinder head | 45 Nm | |
| Spark plugs | 21 Nm | |
| Lambda sensor (Oxygen) | 55 Nm | |
| Knock sensor (KS) | 15 Nm | |
| Chassis tightening torques | ||
| Steering track rod end | 40 Nm | |
| Brake caliper/carrier to hub Front | 82 Nm | |
| Brake caliper/carrier to hub Rear | 82 Nm | |
| Road wheels | 130 Nm | |
Bar lengths use a square-root scale so small and large values stay readable.
Air conditioning
| No. of AC service connectors | 2 |
|---|---|
| Air conditioning restrictor type | Expansion valve |
| Compressor clutch/magnetic coupling | Yes |
| Compressor variable displacement solenoid | No |
| Air conditioning refrigerant Type | R12 |
| Refrigerant type | |
| Air conditioning refrigerant quantity grams | — |
| Refrigerant quantity | |
| Air conditioning oil Type | Suniso 4GS |
| Oil type | |
| Air conditioning oil quantity cm³ | 135±15 |
Frequently asked questions
What is the firing order of the Land Rover Discovery 3.9?
The firing order for the Land Rover Discovery 3.9 (1994–1998) is 1-8-4-3-6-5-7-2.
What spark plugs does the Land Rover Discovery 3.9 use?
The Land Rover Discovery 3.9 (1994–1998) uses Champion RN11YC spark plugs with a 0,6 mm electrode gap.
How much oil does the Land Rover Discovery 3.9 take?
The Land Rover Discovery 3.9 (1994–1998) takes 6.6 litres of engine oil with the filter. A listed engine oil option is SAE 5W-30 for cold climates, with API/ACEA classification SJ/A2. A listed engine oil option is SAE 10W-40 for moderate climates, with API/ACEA classification SJ/A2. A listed engine oil option is SAE 15W-40 as an alternative for moderate climates, with API/ACEA classification SJ/A2. A listed engine oil option is SAE 20W-50 for hot climates, with API/ACEA classification SJ/A2.
What are the valve clearances for the Land Rover Discovery 3.9?
Valve clearances on the Land Rover Discovery 3.9 (1994–1998) are hydraulic — they self-adjust, so no manual clearance figure applies.
What is the cylinder head torque for the Land Rover Discovery 3.9?
The cylinder head bolts on the Land Rover Discovery 3.9 (1994–1998) are tightened in 3 stages: 20 Nm, then 90°, then a final 90°.
What is the ignition timing for the Land Rover Discovery 3.9?
Basic ignition timing for the Land Rover Discovery 3.9 (1994–1998) is 5°±1° BTDC at 800 rpm.