The Volvo B6304T4 is a 2,922 cc, inline‑six turbocharged petrol engine produced between 1998 and 2005. It features dual overhead camshafts (DOHC), variable valve timing (VVT), and a low — pressure turbocharger, delivering outputs between 162 kW (220 PS) and 191 kW (260 PS) with torque figures of 300–350 Nm. Variable valve timing optimizes valve overlap for a balance of low‑end response and high‑rpm power.
Fitted primarily to the S80 and XC90 models, including the 2.9T and…
Production years 1998–2005 meet Euro 3 standards across all markets (EU Type Approval E3 715/2007).
The Volvo B6304T4 is a 2,922 cc inline‑six turbocharged petrol engineered for luxury sedans and SUVs (1998-2005). It combines variable valve timing with a low-pressure turbocharger to deliver smooth, linear power delivery and strong mid-range torque. Designed to meet Euro 3 standards, it balances performance with acceptable emissions for its era.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,922 cc | |
Fuel type | Petrol | |
Configuration | Inline‑6, DOHC, 24‑valve | |
Aspiration | Turbocharged | |
Bore × stroke | 81.0 mm × 90.0 mm | |
Power output | 162–191 kW (220–260 PS) | |
Torque | 300–350 Nm @ 1,800–4,800 rpm | |
Fuel system | Bosch Motronic ME7 sequential injection | |
Emissions standard | Euro 3 | |
Compression ratio | 9.0:1 | |
Cooling system | Water‑cooled | |
Turbocharger | Garrett GT25 low-pressure turbo | |
Timing system | Chain-driven (dual chains) | |
Oil type | Volvo VCC 95200312 (SAE 5W‑40) | |
Dry weight | 185 kg |
The Volvo B6304T4 was used across Volvo's P2 platform with longitudinal mounting. This engine received platform-specific adaptations-reinforced engine mounts in the XC90 SUV-and no significant facelift revisions occurred during its production, ensuring broad parts interchangeability. All adaptations are documented in OEM technical bulletins.
The B6304T4's primary reliability risk is electronic throttle body (ETM) failure, with elevated incidence in high-mileage vehicles. Volvo internal service data indicated a significant failure rate before 150,000 km, while owner surveys frequently cite this as the most common electrical fault. Extended periods of inactivity or voltage fluctuations can accelerate potentiometer wear, making electrical system health critical.
Analysis derived from Volvo technical bulletins (2000-2005) and aggregated European owner association failure statistics (2005-2020). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The B6304T4 is a robust engine mechanically, known for smooth power delivery. Its main weakness is the electronic throttle body (ETM), which often fails in high-mileage cars. With the revised ETM installed and regular oil changes using the correct 5W-40 spec, these engines can reliably exceed 300,000 km. Proper maintenance is key to longevity.
The most frequent issues are electronic throttle body (ETM) failure causing idle problems, leaks from turbocharger oil lines, and failures of the variable valve timing (VVT) solenoid. Intake manifold runner control issues are also common. These are well-documented in Volvo service bulletins, particularly SIB 11131-2003 for the ETM.
This 2.9L turbo petrol engine was used in the first-generation Volvo S80 (1998-2005) in 2.9T and T6 trims, and the first-generation Volvo XC90 (2002-2005) in the T6 trim. It was not used in any other manufacturers' vehicles and is specific to Volvo's P2 platform.
Yes, the B6304T4 responds well to ECU remapping. Stage 1 tunes can safely increase power to around 220-240 kW (300-325 PS) by adjusting boost and fueling. The stock internals are strong, but supporting modifications like a downpipe and intercooler are recommended for higher stages to manage heat and flow.
Fuel economy is moderate for its size and era. Expect around 12.5 L/100km (22.5 mpg UK) in city driving and 8.5 L/100km (33 mpg UK) on the highway in an S80. Real-world combined figures typically range from 25-28 mpg UK, heavily influenced by driving style and vehicle condition.
Yes. The B6304T4 is an interference engine. If the timing chain fails or jumps, the pistons will collide with the open valves, causing catastrophic internal damage. Fortunately, the dual timing chains are very durable and rarely fail if oil is changed regularly.
Volvo specifies a 5W-40 synthetic oil meeting their VCC 95200312 standard. This is critical for protecting the turbocharger and ensuring proper operation of the variable valve timing system. Using a lower-quality oil can lead to sludge buildup and premature component failure.
Comprehensive technical documentation and regulatory references
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VOLVO Official Site
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EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
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