The Vauxhall CIH 3.0L S is a 2,994 cc, inline‑six naturally aspirated petrol engine produced between 1975 and 1986. It features a single overhead camshaft (SOHC), two valves per cylinder, and a cast — iron block with an aluminium head. In standard form it delivered 96 kW (130 PS) and 221 Nm of torque, engineered for relaxed cruising and robust mechanical simplicity.
Fitted to models such as the Vauxhall Royale, Senator A, and early Carlton, the CIH 3.0L S was designed for execu…
Pre‑1983 models are pre‑Euro; post‑1983 export variants may meet Euro 1 standards in limited markets .
The Vauxhall CIH 3.0L S is a 2,994 cc inline‑six naturally aspirated petrol engine engineered for executive sedans (1975–1986). It combines a robust cast‑iron block with a single overhead camshaft and twin‑carburettor or fuel‑injected induction to deliver smooth, linear power and long service life. Designed before modern emissions mandates, later variants incorporated catalytic converters for select markets.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,994 cc | |
Fuel type | Petrol | |
Configuration | Inline‑6, SOHC, 12‑valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 95.0 mm × 105.0 mm | |
Power output | 96 kW (130 PS) | |
Torque | 221 Nm @ 3,200 rpm | |
Fuel system | Twin Zenith carburettors (early) / Bosch L‑Jetronic (late) | |
Emissions standard | Pre‑Euro (1975–1982); Euro 1 (1983–1986, select markets) | |
Compression ratio | 8.8:1 (carb); 9.2:1 (injected) | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Chain (front‑mounted) | |
Oil type | SAE 20W‑50 mineral oil (API SF/CC) | |
Dry weight | 185 kg |
The Vauxhall CIH 3.0L S was used across Vauxhall's Royale, Senator A, and Carlton Mk1 platforms with longitudinal mounting and shared with Opel under GM Europe’s executive strategy. This engine received platform-specific adaptations—reinforced transmission mounts in the Senator and revised cooling ducts in the Carlton—creating minor service part differences. All adaptations are documented in OEM technical bulletins.
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The CIH 3.0L S's primary reliability risk is camshaft and tappet wear, with elevated incidence in vehicles using modern low‑detergent or low‑ZDDP oils. Vauxhall workshop data from 1982 indicated up to 22% of high‑mileage engines required cam replacement before 150,000 km when serviced with incorrect lubricants, while UK DVLA records show cooling system failures as the second-most common issue in surviving examples. Infrequent oil changes and short‑trip driving accelerate wear, making oil specification and maintenance adherence critical.
Analysis derived from Vauxhall technical bulletins (1978–1985) and UK DVLA/DVSA historical records (1990–2023). 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 CIH 3.0L S is mechanically robust and smooth-running, but reliability hinges on correct oil usage. Early cam wear is common if modern low-ZDDP oils are used. With proper 20W‑50 mineral oil and 5,000 km service intervals, many engines exceed 250,000 km. The simple SOHC design is easier to rebuild than modern DOHC units.
Top issues include camshaft/tappet wear due to incorrect oil, coolant leaks from the cast-iron block, carburettor faults (on early models), and timing chain stretch. These are documented in Vauxhall TSB 78‑05‑09 and historical workshop records. Oil leaks from the rear main seal are also frequent after 120,000 km.
The CIH 3.0L S powered the Vauxhall Royale (1975–1978), Senator A (1978–1986), and Carlton Mk1 (1978–1986). It was also used by Opel in the Senator A and Rekord E. Pre-1983 models are carburetted; 1983–1986 variants use Bosch L-Jetronic fuel injection.
Yes. Common upgrades include performance camshafts, ported heads, twin Weber carburettors, or aftermarket EFI. Output can reach 160–180 PS with supporting mods. However, the bottom end is robust but not designed for high-RPM use—keep revs below 6,000 rpm for longevity.
In a Senator 3.0 S, expect ~14.5 L/100km (city) and ~9.8 L/100km (highway), or about 19 mpg UK combined. Real-world mixed driving typically yields 17–21 mpg (UK). Economy is significantly worse with carburettor issues or incorrect ignition timing.
No. The CIH 3.0L S is a non-interference engine. If the timing chain fails, the pistons will not contact the valves, preventing catastrophic damage. This makes it more forgiving than modern interference designs.
Vauxhall specifies a high-ZDDP SAE 20W‑50 mineral oil meeting API SF/CC standards. Modern low-SAPS or synthetic oils lack the anti-wear additives needed for flat-tappet cams. Change oil every 5,000 km or 6 months to prevent cam lobe wear.
Comprehensive technical documentation and regulatory references
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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
Type-approval guidance and documentation.
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