Land Rover Discovery 2 4.0 V8 faults and fixes

Won't start (petrol)

Diagnose

1. Check for spark: pull a plug lead, hold it 6 mm from earth (insulated pliers) and crank. A fat blue spark is good.
2. No spark: remove the cap, crank, and watch the points open and close. Check the gap and that the low-tension lead isn't shorting to the base plate.
3. Weak or orange spark: suspect the condenser, then the coil.
4. Good spark: remove the air cleaner, open the throttle and look for fuel squirting from the accelerator pump. Disconnect the pipe at the carb and crank to check the pump delivers.
5. Smell of fuel and wet plugs means flooding: hold the throttle wide open (no choke) and crank to clear it.

Fix

1. Dry the cap and leads; fit a new cap and rotor if cracked or tracked.
2. Clean and re-gap the points or fit new points and a new condenser; reset the timing.
3. Clean the fuel pump gauze and bowl, or fit a new pump.
4. Free or replace the float needle if flooding.
5. Charge or replace the battery and clean the earth straps.

Overheating

Diagnose

1. Check coolant level cold and look for leaks with the engine at pressure.
2. With the engine hot, feel the radiator: cold patches mean blocked tubes.
3. Feel the top and bottom hoses as it warms up: the top hose should get hot suddenly when the thermostat opens.
4. Hot engine, stopped: the viscous fan should be hard to turn by hand (use a rolled newspaper, never fingers near a moving fan).
5. Look for constant bubbles in the expansion tank or a sweet exhaust smell (head gasket). A sniffer test (block tester) confirms.

Fix

1. Replace leaking hoses and clips; replace the water pump if it weeps from the drain hole or the bearing has play.
2. Flush or re-core/replace the radiator.
3. Fit a new thermostat and gasket.
4. Adjust or replace the fan belt.
5. Replace the viscous coupling.
6. Head gasket: remove the head, check it for flatness, fit a new gasket (Tdi: match the hole-count marking) and new bolts where required.

Engine oil leaks

Diagnose

1. Degrease the engine, drive 10 miles and look for where the oil starts. Oil runs down and back, so look high and forward.
2. A drip from the bell housing drain hole points to the rear crank seal (or gearbox input seal; gearbox oil smells different).
3. Check the breather and its hoses are clear: a blocked breather pushes oil out of every seal.

Fix

1. Replace the rocker cover gasket, half-moon seals and breather O-ring (Tdi).
2. Fit a new sump plug washer; reseal the sump if needed.
3. Front seal: remove the crank pulley and fit a new seal (Tdi: done with the timing belt).
4. Rear seal: gearbox out. Check the crank for a groove worn by the old seal.

Swivel ball leaking or pitted (coil-sprung)

Diagnose

1. Clean the ball and inspect the chrome for pitting.
2. Check for play at the swivel with the wheel off the ground.
3. Drive slowly on full lock: clicking means the CV joint.

Fix

1. Remove the brake caliper (hang it up, don't strain the hose), hub, stub axle and halfshaft/CV.
2. Remove the swivel pins and swivel housing.
3. Replace the ball if pitted. Fit a new seal kit and swivel pin bearings and set the preload.
4. Refill with one-shot grease (or EP90 on early axles) and refit everything with new hub seals and lock tabs.

Hub seal leak / oil on brakes

Diagnose

1. Check the diff and swivel levels aren't overfilled and the axle breather is clear.
2. Check for bearing play.
3. Once apart, feel the stub axle seal surface for a groove.

Fix

1. Remove the hub. Replace both hub seals and the bearings if worn.
2. Adjust the hub bearing nut and lock with a new tab washer.
3. Replace contaminated brake shoes or pads; you can't clean oil out of them.
4. Coil-sprung: some owners prefer the double-lip RTC3511 seal; check it sits deep enough not to rub and fit it the right way round.

Brakes pull, judder or squeal (disc brakes)

Diagnose

1. Check pad thickness and whether both pads on a wheel wear evenly.
2. Spin each wheel after braking: a dragging wheel has a sticking caliper or hose.
3. Measure disc thickness and look for a lip.

Fix

1. Fit new pads (axle set) and discs if below minimum or warped.
2. Free or rebuild sticking calipers; replace if the bore is pitted.
3. Replace old hoses and bleed with fresh DOT4.

Handbrake won't hold

Diagnose

1. Adjust it first at the back-plate adjuster on the rear of the transfer box.
2. If it still won't hold, remove the drum and look for oil on the shoes.
3. Check the expander moves freely.

Fix

1. Replace the transfer box rear output seal if leaking.
2. Fit new handbrake shoes and clean the drum.
3. Free or replace the expander and its boot.

Death wobble (violent steering shake)

Diagnose

1. With a helper rocking the steering wheel, watch every joint from the box to the wheels for lost motion.
2. Check the steering damper: it should resist evenly both ways.
3. Lever the radius arm and panhard rod bushes for movement.
4. Check swivel preload with the track rod disconnected.
5. Check wheel balance and tyre condition.

Fix

1. Replace worn ball joints (often as a kit).
2. Fit a new steering damper.
3. Replace worn radius arm and panhard rod bushes.
4. Set swivel preload.
5. Tighten the steering box bolts and check the chassis around them for cracks.

Clutch slipping or won't disengage

Diagnose

1. Check the clutch fluid level and look for fluid at the slave cylinder.
2. Pump the pedal: if it firms up, there's air in the system.
3. Slipping in a high gear under load means a worn or oily plate.

Fix

1. Replace the slave or master cylinder and bleed.
2. Gearbox out: fit a clutch kit; fix the rear crank seal at the same time if oily.
3. Series: check the cross-shaft and its pins and bushes while it's apart.

Clunk on taking up drive

Diagnose

1. Twist each propshaft against its flange: any free movement at a UJ means it's worn.
2. Remove a hub cap and drive member and check spline wear.
3. Check mounts.

Fix

1. Replace UJs (or the propshaft) and grease them.
2. Replace worn drive flanges and halfshafts as needed (Series: note 10 or 24 spline).
3. Tighten propshaft bolts.

Battery not charging

Diagnose

1. Measure battery voltage at rest (about 12.6 V) and at 2,000 rpm (about 13.8–14.4 V).
2. Check belt tension.
3. Check the earth straps from battery to chassis and engine to chassis.

Fix

1. Tension or replace the belt.
2. Dynamo: replace brushes or the dynamo, and the control box if its contacts are burnt.
3. Replace or recondition the alternator.
4. Clean and tighten all earth connections.

Rotten rear crossmember or outriggers

Diagnose

1. Tap all over with a hammer: sound steel rings, rotten steel thuds.
2. Pay particular attention to the rear crossmember, spring hangers (Series), outriggers and the rear body mounts.

Fix

1. Replacement crossmembers and outriggers are made for every model; they are cut out and welded in.
2. Remove the rear tub or body tub mounts for access as needed.
3. Paint and inject cavity wax afterwards.
4. Extensive rot: a galvanised replacement chassis may cost less than repairs.

Differential whine or clonk

Diagnose

1. Check the oil level and condition. Milky oil means water.
2. Check pinion flange play: up-and-down movement means bearing wear.

Fix

1. Refill with fresh oil and clear the breather.
2. Replace pinion bearings and seal, or fit a reconditioned differential.
3. Replace a broken halfshaft.

Misfire, flat spot or poor economy (petrol)

Diagnose

1. Check points gap and timing.
2. With the engine idling, spray carb cleaner around the throttle spindle and manifold: a change in idle means an air leak.
3. Check the dashpot damper oil on Stromberg/SU carbs.

Fix

1. Service the ignition.
2. Rebush the throttle spindle or fit a replacement carburettor.
3. Top up the damper.
4. Clean jets with a carb service kit.
5. Replace manifold gaskets.

Engine knock

Diagnose

1. Check oil level and pressure with a gauge.
2. Pull each injector lead or plug lead in turn (petrol) or crack each injector pipe (diesel): if the knock changes, it's in that cylinder.
3. A light tapping at half engine speed is usually valve gear: check clearances.

Fix

1. Valve gear: adjust or replace rockers and followers.
2. Bearings: drop the sump and inspect. Bearings and crank regrind, or a reconditioned engine.
3. Don't keep driving a bearing knock; it ends in a broken crank or rod.

V8 tapping, cam and timing chain wear

Diagnose

1. Use a stethoscope to locate the tapping on one bank.
2. With the distributor cap off, rock the crank and watch the rotor: lots of lag means a stretched chain.

Fix

1. Fit a new camshaft and followers as a set, with fresh oil and a proper run-in.
2. Fit a new timing chain and gears.
3. Change oil more often afterwards.

V8 coolant loss: slipped liner, cracked liner or porous block (Discovery 2 4.0)

Diagnose

1. Do a combustion-gas (block) test on the expansion tank: a positive result means exhaust gas in the coolant.
2. Pressure-test the cooling system cold and see where it goes.
3. Remove the plugs: a clean, steam-washed plug or a misfire on one cylinder points to coolant in that cylinder.
4. With the heads off, check each liner's height against the block deck and look for vertical cracks.

Fix

1. A head gasket alone rarely lasts if a liner has moved. The proper fix is a block with top-hat liners or a specialist-rebuilt engine.
2. Short term: keep the coolant strong and the level checked, and avoid heavy loads.
3. Cooling system: new radiator, thermostat and hoses so the rebuilt engine stays cool.

ABS, traction control and hill descent lights on together (Discovery 2)

Diagnose

1. Read the ABS fault codes with a scanner that covers the Discovery 2 ABS (Wabco). It names the sensor or circuit.
2. Check the brake lights work: a failed brake light switch triggers the lights.
3. Remove the named sensor, clean it and its bore, and check its resistance and wiring for chafing.
4. Check battery voltage while cranking and charging.

Fix

1. Clean and refit, or replace, the faulty wheel speed sensor (fit with a smear of grease and push fully home).
2. Repair chafed wiring and corroded plugs.
3. Replace the brake light switch.
4. Modulator faults: a specialist repair or exchange unit, then bleed the brakes as the workshop manual describes.

ACE warning, body roll, or rear sagging (Discovery 2 ACE / SLS)

Diagnose

1. Check the ACE reservoir level and follow the pipes under the vehicle for wet, rusty sections and failed clips.
2. Check each ACE actuator on the anti-roll bars for leaks.
3. SLS: park overnight; spray the rear air springs with soapy water to find leaks.
4. Read ACE and SLS fault codes with a suitable scanner.

Fix

1. Replace corroded ACE pipes with new pipes (or a full pipe set) and bleed the system with the specified fluid as the workshop manual describes.
2. Replace a leaking actuator or valve block.
3. Replace perished SLS air springs in pairs; repair or replace the compressor.
4. Some owners convert to standard anti-roll bars or rear coil springs; check insurance and the effect on handling first.

V8 fuel injection: poor starting, hunting idle or misfire (14CUX / GEMS / Bosch)

Diagnose

1. Read the fault codes: 14CUX with a suitable reader, the Discovery 2's GEMS or Bosch system with an OBD-capable or Land Rover tool.
2. With the engine idling, spray carb cleaner around the plenum gasket and hoses: a change in idle means an air leak.
3. Check the coolant temperature sensor resistance against the chart in your manual (cold and hot).
4. Check fuel pressure with a gauge at the fuel rail.
5. Check the plugs and leads; swap coil packs to see if a misfire moves.

Fix

1. Clean the throttle body and idle motor; replace a faulty idle motor.
2. Replace the faulty sensor (airflow meter or coolant sensor).
3. Renew leaking hoses and gaskets.
4. Replace the fuel filter; test the pump and regulator.
5. Fit new plugs, leads, and cap and rotor or coil packs as needed.

Water leaks into the cabin (Discovery 1 & 2, Range Rover Classic)

Diagnose

1. Pour water into each sunroof corner and the scuttle: it should run out under the vehicle.
2. Have a helper hose the roof, screen and doors section by section while you look inside with a torch.
3. A sweet smell and greasy mist on the inside of the screen point to the heater matrix, not rain.

Fix

1. Clear drains with strimmer line or compressed air.
2. Reseal or replace the leaking seal or window.
3. Replace the heater matrix.
4. Dry the carpets and check connectors that got wet.