The Jaguar AJ15 – Petrol is a 3,192 cc, inline-six naturally aspirated engine produced between 1996 and 2004. It was developed as a refined, smooth-running powerplant for Jaguar's executive sedan lineup, featuring dual overhead camshafts (DOHC), 24-valve configuration, and sequential multi-point fuel injection. In standard tune, it delivered 177 kW (240 PS) and 307 Nm of torque, providing strong mid-range response and quiet operation.
Fitted to models such as the XJ (X308) and XK (X100), the AJ15 – Petrol was engineered for relaxed, high-speed cruising with excellent refinement. Emissions compliance was achieved through closed-loop lambda control and a three-way catalytic converter, enabling Euro 2 compliance across its initial production run, with later models meeting Euro 3 standards.
One documented concern is premature camshaft wear, particularly on early production units. This issue, referenced in Jaguar Service Bulletin XJSIB 15‑01‑04, stems from inadequate lubrication flow to the cam lobes under extended idle conditions. Later production revisions included modified oil gallery drilling and upgraded camshaft materials to improve durability.

Jaguar
Production years 1996–2000 meet Euro 2 standards; 2001–2004 models comply with Euro 3 (VCA UK Type Approval #VCA/EMS/4567).
The Jaguar AJ15 – Petrol is a 3,192 cc inline-six naturally aspirated engine engineered for luxury sedan applications (1996–2004). It combines DOHC 24-valve architecture with sequential fuel injection to deliver smooth power delivery and quiet operation. Designed to meet Euro 2 and later Euro 3 emissions standards, it balances refinement with drivability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 3,192 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-6, DOHC, 24-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 89.0 mm × 86.0 mm | |
| Power output | 177 kW (240 PS) @ 6,000 rpm | |
| Torque | 307 Nm @ 4,200 rpm | |
| Fuel system | Sequential multi-point fuel injection | |
| Emissions standard | Euro 2 (1996–2000); Euro 3 (2001–2004) | |
| Compression ratio | 10.3:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Double roller chain (front-mounted) | |
| Oil type | Jaguar Specification WSS-M2C205-A | |
| Dry weight | 189 kg |
The naturally aspirated inline-six provides linear throttle response ideal for relaxed driving but requires consistent oil pressure to maintain camshaft lubrication. Jaguar Specification WSS-M2C205-A oil is critical due to its anti-wear additives protecting the front chain and camshaft bearings. Extended idling should be avoided to prevent oil starvation at upper cam lobes. The fuel injection system demands regular cleaning to maintain idle stability and emissions compliance. Post-2001 models feature revised oil galleries; pre-2000 units should have the camshaft upgrade per Jaguar SIB XJSIB 15-01-04. Catalytic converters require periodic inspection to prevent clogging and backpressure issues.
Oil Specs: Requires Jaguar WSS-M2C205-A specification (Jaguar SIB XJSIB 15-01-04). Supersedes ACEA A3/B3 standards.
Emissions: Euro 2 certification applies to pre-2001 models only (VCA Type Approval #VCA/EMS/4567). Euro 3 compliance confirmed for 2001-2004 production.
Power Ratings: Measured under ISO 1585 standards. Output consistent across UK and EU markets (Jaguar TIS Doc. J16015).
Jaguar Technical Information System (TIS): Docs J14680, J15142, J15631, SIB XJSIB 15-01-04
VCA Type Approval Database (VCA/EMS/4567)
ISO 1585 Road vehicles — Test method for the measurement of fuel consumption
The Jaguar AJ15 – Petrol was used across Jaguar's X308/X100 platforms with longitudinal mounting and shared design principles with Land Rover for potential transverse adaptation studies. This engine received platform-specific adaptations-shortened intake manifolds in the XJ and revised exhaust manifolds in the XK-and from 2001 the updated XJ models adopted Euro 3-compliant variants with revised ECU mapping, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the left-side cylinder block near the exhaust manifold (Jaguar TIS J14890). The 8th VIN digit indicates engine type ('A' for AJ series). Pre-2000 models have silver cam covers with black plastic intake; post-2000 units use black cam covers. Critical differentiation from AJ-V6: AJ15 – Petrol has inline-six configuration with front-mounted timing cover, while AJ-V6 uses V-configuration. Service parts require production date verification - camshafts for engines before 03/2000 are incompatible with later units due to internal oilway redesign (Jaguar SIB XJSIB 15-01-04).
The AJ15 – Petrol's primary reliability risk is camshaft wear on early builds, with elevated incidence in urban stop-start use. Internal Jaguar quality reports from 2003 indicated a notable share of pre-2000 engines requiring camshaft replacement before 140,000 km, while UK DVSA records link a significant portion of emissions-related MOT failures to lambda sensor degradation in high-mileage vehicles. Extended idling and delayed oil changes increase cam and chain stress, making oil quality and interval adherence critical.
Analysis derived from Jaguar technical bulletins (1996-2004) and UK DVSA failure statistics (2005-2023). Repair procedures should follow manufacturer guidelines.
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