4.2 V8 Supercharged: Jaguar AJ34S

The performance petrol of the Jaguar era: a 4.2-litre supercharged V8 making about 294 kW and 560 Nm. It turns the L322 into a seriously fast luxury barge, 0-100 km/h in around 7.5 seconds, while keeping the refinement intact. The price is greater thirst and more complexity than the naturally aspirated 4.4.

Jaguar AJ34S 4.2 supercharged V8 engine in a Range Rover L322

Jaguar AJ34S 4.2 Supercharged V8, 2006-2009 · engine photo

ENGINE QUICK FACTS

Engine code	Jaguar AJ34S
Type	4.2 V8 supercharged
Power	294 kW @ 5,750
Torque	560 Nm @ 4,000
0-60	7.5 s
Years	2006-2009
Gearbox	ZF 6HP26
Verdict	Fast, very thirsty

AT A GLANCE Reliability: ●●●○○ good if maintained · Performance: ●●●●○ fast · Running cost: high (thirsty, complex)

Strengths	Weaknesses
+ Strong, effortless performance	– Heaviest fuel use of the era
+ Same refined AJ-V8 base	– Supercharger + intercooler add maintenance
+ Electronic rear diff fitted	– Higher loads on gearbox/cooling

Specifications

Engine code	AJ34S (Land Rover-adapted)
Configuration	90° V8, supercharged?Supercharger: a belt-driven air pump (here an Eaton Roots-type) that forces extra air into the engine for more power, with instant response and no turbo lag.
Displacement	4,196 cc
Forced induction	Eaton Roots-type supercharger + intercooler?Intercooler: cools the compressed (and therefore hot) air from the supercharger before it enters the engine, raising density and power and lowering knock risk.
Power	approx. 294 kW @ 6,100 rpm
Torque	approx. 560 Nm @ 3,500 rpm
0-100 km/h	approx. 7.5 seconds
Gearbox	ZF 6HP26 6-speed automatic
Years in L322	2006-2009

Performance & economy

Manufacturer / period figures; real-world economy is typically lower. Petrols were often LPG-converted to cut fuel costs.

0-100 km/h	7.5 sec
Top speed	209 km/h
Economy	~16.1 l/100km (combined)
CO₂ emissions	~376 g/km
Kerb weight	~2,550 kg
Displacement	4,196 cc
Power (alt.)	294 kW @ 5,750
Torque	560 Nm @ 4,000

Power vs the L322 range

This engine	294 kW
Range span	130 kW (Td6) to 375 kW (5.0 S/C)

Design & technology

Based on the Jaguar AJ-V8, the supercharged unit adds an Eaton supercharger nestled in the vee with an intercooling system. Land Rover's version is adapted from Jaguar's with its own sump and calibration. Supercharged and TDV8 cars also gained an electronic rear differential and the "Positive Torque" throttle blip for faster downshifts.

Performance

This is the L322 that surprises sports saloons away from lights: instant supercharger response, 560 Nm of shove and a top speed limited to around 209 km/h. It transforms the car's character from stately to rapid while staying smooth and quiet at a cruise.

Reliability

The base engine is the robust AJ-V8, so the bottom end is sound. The added supercharger, intercooler pump and the extra heat and load are what need attention. A well-maintained example is dependable, a neglected one gets expensive.

Common faults to check

Issue	Symptom & notes
Supercharger noise/wear	Whine or rattle; nose-cone bearings and coupler can wear.
Intercooler pump	Auxiliary water pump fails; check charge-air cooling.
Cooling under load	Works hard in a heavy car; keep system in top condition.
Gearbox load	ZF6 sees more torque; service fluid, watch for slip.
Fuel cost	Not a fault but real: expect heavy consumption.

Maintenance notes

Service the supercharger oil/coupler as specified; listen for bearing whine.
Check the intercooler circuit and its pump, a common weak spot.
Keep cooling and gearbox fluid fresh given the extra load.
Use good fuel and keep up oil changes as with any AJ-V8.

Verdict

VERDICT A fast, refined, charismatic L322 built on the dependable AJ-V8. Great if you want pace and can absorb the fuel bills and the extra supercharger/intercooler upkeep. For pure longevity the naturally aspirated 4.4 is simpler; for outright speed the later 5.0 S/C is the heir.

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