4.2 V8 Supercharged — Jaguar AJ34S
Last updated: 18 June 2012
The performance petrol of the Jaguar era: a 4.2-litre supercharged V8 making about
396 hp and 550 Nm. It turns the L322 into a genuinely fast luxury barge —
0-60 mph in around 7.5 seconds — while keeping the refinement intact. The price is greater
thirst and more complexity than the naturally aspirated 4.4.
[ ▲ ] Photo: 4.2 supercharged V8 engine bay add image here
ENGINE QUICK FACTS
| Engine code | Jaguar AJ34S |
| Type | 4.2 V8 supercharged |
| Power | 396 hp @ 5,750 |
| Torque | 550 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. 396 hp (291 kW) @ 6,100 rpm |
| Torque | approx. 550 Nm (410 lb-ft) @ 3,500 rpm |
| 0-60 mph | 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.
| 0-60 / 0-62 mph | 7.5 sec (0-62) |
| Top speed | 130 mph (209 km/h) |
| Economy | ~17.6 mpg (combined) |
| CO₂ emissions | ~376 g/km |
| Kerb weight | ~2,550 kg |
| Displacement | 4,196 cc |
| Power (alt.) | 400 hp @ 5,750 |
| Torque | 550 Nm / 413 lb-ft @ 4,000 |
Power vs the L322 range
| This engine |
396 hp |
| Range span | 177 hp (Td6) ——— 510 hp (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,
550 Nm of shove and a top speed limited to around 130 mph. 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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