The Volvo B 6304 GS is a 2,922 cc, V6 petrol engine produced between 1990 and 1998. It features a cast‑iron block, aluminum heads, single overhead camshafts (SOHC) per bank, and multi-point fuel injection. This unit delivered 130 kW (177 PS) and 260 Nm of torque, engineered for smooth, refined power in Volvo’s flagship executive models.
Fitted primarily to the 960 sedan and wagon, the B 6304 GS was designed for drivers seeking effortless cruising, strong mid-range torque, and luxurious comfort. Emissions compliance was achieved through catalytic converters and basic engine management, meeting Euro 2 standards across all markets.
One documented concern is premature failure of the distributor cap and rotor due to heat exposure, potentially leading to misfires. This issue, highlighted in Volvo Technical Service Bulletin 6‑93‑008, is often linked to the engine’s tight packaging and proximity to the exhaust manifold. In 1998, Volvo phased out the B6304 in favor of the modular inline-six engines.
Production years 1990–1998 meet Euro 2 emissions standards (Swedish Transport Agency Type Approval #STV/B6304/1990).
The Volvo B 6304 GS is a 2,922 cc V6 petrol engine engineered for executive sedans and wagons (1990-1998). It combines a 60-degree V6 architecture with SOHC and multi-point fuel injection to deliver smooth, linear power. Designed to meet Euro 2 emissions standards, it prioritizes refinement and torque for relaxed highway cruising.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,922 cc | |
| Fuel type | Petrol | |
| Configuration | V6, SOHC, 12-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 81.0 mm × 94.0 mm | |
| Power output | 130 kW (177 PS) @ 5,200 rpm | |
| Torque | 260 Nm @ 4,000 rpm | |
| Fuel system | Multi-point fuel injection (Bosch LH-Jetronic 3.2) | |
| Emissions standard | Euro 2 | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Belt-driven single overhead camshaft per bank | |
| Oil type | SAE 10W-40 (API SG/CC) | |
| Dry weight | 175 kg |
The 60-degree V6 design provides exceptionally smooth operation ideal for luxury sedans but requires strict 60,000 km timing belt replacement intervals for both banks to prevent failure. The Bosch LH-Jetronic system is mechanically robust but sensitive to voltage spikes and poor grounding. The distributor is prone to heat damage from the exhaust manifold per Volvo TSB 6-93-008; ensuring the heat shield is intact is critical. Regular valve clearance checks (every 30,000 km) are necessary.
Oil Specs: Requires API SG/CC specification oil (SAE 10W-40) for optimal bearing and valve train protection (Volvo TSB 6-93-008).
Emissions: Euro 2 certification applies to all models in this production period (Swedish Transport Agency #STV/B6304/1990).
Power Ratings: Measured under SAE net standards. Output is consistent across 960 applications (Volvo Tech Spec 1990).
Volvo Workshop Manual (1990)
Volvo Technical Specification Sheet (1990)
Volvo Technical Service Bulletin 6-93-008
Swedish Transport Agency Type Approval #STV/B6304/1990
The Volvo B 6304 GS was used exclusively across Volvo's 900 Series platform with longitudinal mounting. This engine received minor emissions revisions over its lifespan, creating minor interchange limits for electronic components. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on a flat pad on the front of the left cylinder bank, near the timing cover (Volvo Workshop Manual 1990). The code will read "B6304GS". Visual identification: Cast iron block, two aluminum cylinder heads with cam covers, two timing belt covers on the front, and a prominent distributor mounted at the rear of the left cylinder head. Critical differentiation from B6254: B6304 has a larger displacement (3.0L vs 2.5L). Ancillary parts are specific to the 960; consult EPC for exact fitment.
The B 6304 GS's primary reliability risk is heat damage to the distributor cap and rotor, as documented in Volvo TSB 6-93-008. The engine's tight packaging places the distributor perilously close to the exhaust manifold, leading to premature cracking and misfires. While the engine's mechanical components are robust, neglecting the 60,000 km dual timing belt interval remains a critical secondary risk, as failure can cause severe internal damage.
Analysis derived from Volvo technical bulletins (1990-1998) and historical workshop manual data. Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VOLVO B-6304-GS.
Comprehensive technical documentation and regulatory references
Independent Technical Reference
EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with VOLVO or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.
Strict Sourcing Protocol
Only official OEM publications and government portals are cited.
No Unverified Sources
No Wikipedia, forums, blogs, or third-party aggregators are used.
Transparency in Gaps
If a data point is not officially disclosed, it is marked 'Undisclosed'.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
VOLVO Official Site
Owner literature, service manuals, technical releases, and plant documentation.
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
Type-approval guidance and documentation.
Data Compilation
All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.
Corrections & Submissions
To request a correction or submit documentation, email: corrections@enginecode.uk
Fair Dealing Use
All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
GDPR Compliance
EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.
Data Requests
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
No Paid Endorsements
This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.
Funding Model
Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.
All specifications and compatibility data verified against officialVOLVO documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed“ .
All external links open in new tabs. Please verify current availability of resources.
