🏷️ Basic Information

Make:

Maserati

Model:

Biturbo

Model Variants Covered:

Coupe, S, Si, Spider, i, 420, 222, 2.24V, 422, SE, Spider, 425, 222E, Spyder i, 228, 228i, 430, Karif

Production Years:

1987-1992

Platform Code:

AM331 / AM332 / AM337 (varies by variant)

👋 Introduction

Brand Perception:

Maserati Biturbo represented Maserati's effort to produce a more accessible and mass-market sports car, blending Italian flair with performance. Positioned against German and Italian rivals in the premium sports coupe and sedan segment.

Competitors:

BMW 3 Series (E30), Mercedes-Benz 190E, Alfa Romeo GTV/75, Porsche 944.

Distinctive Attributes:

Twin-turbocharged V6 engines, luxurious interiors, distinctive styling, rear-wheel drive, sporting chassis dynamics.

Value Proposition:

Essential resource for owners and independent workshops to maintain and repair these complex and rewarding Italian sports cars, addressing the inherent need for specialized knowledge.

📋 Manual Details

Manual Type:

Workshop Factory Service Repair Manual

Language:

English

Format:

PDF

Page Count Estimate:

Extensive (typically 1000+ pages for such comprehensive manuals)

📖 Manual Coverage

Engine Mechanical:

Detailed diagnosis, overhaul, and repair of 2.0L, 2.5L, and 2.8L V6 twin-turbocharged engines (including carbureted and fuel-injected variants). Covers cylinder heads, block assembly, crankshaft, connecting rods, pistons, camshafts, timing systems (including timing belt replacement), lubrication system, cooling system.

Fuel System:

Carburetor (Weber) and fuel injection (Bosch LE2-Jetronic, L-Jetronic, Motronic) systems. Includes fuel pump, injectors, fuel pressure regulator, fuel lines, and emissions control systems.

Ignition System:

Ignition coil, distributor, spark plugs, ignition timing, electronic ignition control units.

Transmission:

Manual and automatic transmission overhaul, repair, and adjustment. Covers clutch operation, gearbox internals, differential, and torque converter (for automatics).

Drivetrain:

Driveshafts, universal joints, rear axle assembly, lubrication, and repair.

Brakes:

Front and rear disc brakes, hydraulic system, ABS (if equipped), brake pad replacement, caliper overhaul, bleeding procedures, parking brake.

Suspension:

Front and rear independent suspension, shock absorbers, springs, bushings, control arms, alignment specifications.

Steering:

Power steering system, steering rack, tie rods, steering column, lubrication, and repair.

Electrical System:

Complete wiring diagrams, battery, alternator, starter motor, lighting system, instrument cluster, dashboard controls, power windows, central locking, fuse box layout, diagnostic connectors.

Body And Chassis:

Body panel repair, door mechanisms, hood, trunk, interior trim, glass replacement, structural components.

Climate Control:

Air conditioning system (refrigerant, compressor, condenser, evaporator), heating system, ventilation.

Maintenance:

Scheduled maintenance intervals, oil changes, filter replacements, spark plug replacement, timing belt replacement, fluid checks and replacements (coolant, brake fluid, power steering fluid, transmission fluid).

Troubleshooting:

Systematic diagnostic procedures for common faults, fault codes (where applicable), symptom-based troubleshooting guides.

Repair And Overhaul:

Step-by-step instructions for component disassembly, repair, reassembly, and adjustment for all major systems.

Specifications And Data:

Torque specifications, clearances, tolerances, fluid capacities, electrical resistance values, diagnostic parameter ranges.

Depth:

Comprehensive: Covers everything from basic fluid checks and filter changes to complete engine and transmission rebuilds, including detailed electrical system diagnostics and bodywork repairs. Designed for professional technicians but accessible to advanced DIY enthusiasts.

📊 Manual Specifications

Digital Format:

PDF

Searchability:

Likely text-searchable PDF, allowing for quick navigation to specific topics.

Printability:

Printable pages for on-the-job use.

Quality:

N/A (Digital PDF - quality depends on original source scans)

Binding:

N/A (Digital PDF)

Paper:

N/A (Digital PDF)

⚙️ Engine Specifications

Configuration:

V6, 60-degree bank angle, twin-turbocharged

Displacements:

1996 cc (2.0L), 2493 cc (2.5L), 2790 cc (2.8L)

Engine Codes:

AM272, AM456, AM457, AM472 (examples, specific codes vary by sub-model)

Horsepower Range:

Approximately 180 hp to 250 hp depending on engine size and tune (e.g., 2.0L to 2.8L, 2.24V variant).

Torque Range:

Approximately 250 Nm to 370 Nm depending on engine size and tune.

Carbureted Models:

Weber twin-choke carburetors (e.g., 2.0L models).

Fuel Injected Models:

Bosch K-Jetronic, KE-Jetronic, LE2-Jetronic, Motronic systems.

Turbocharging:

Twin IHI turbochargers (typical) with intercoolers.

Coolant Type:

Ethylene Glycol based coolant (refer to manual for specific Maserati recommended types, typically a 50/50 mix).

🔧 Transmission

Manual Transmission:

5-speed manual (Getrag 260/5, ZF 5HP18 for some models/years).

Automatic Transmission:

3-speed or 4-speed automatic (e.g., ZF 3HP22).

Transmission Fluid Spec:

Refer to manual for specific ATF types (e.g., Dexron III for automatics, GL-4 for manuals).

📐 Dimensions

Body Styles:

2-door Coupe, 2-door Spider (convertible).

Length Approx:

4300-4600 mm (varies by model and variant)

Wheelbase Approx:

2550-2640 mm (varies by model and variant)

Curb Weight Approx:

1300-1550 kg (varies by model and variant)

🛡️ Safety Features

Crash Test Data:

Limited comprehensive modern crash test data available for this era of Maserati. Safety was more focused on passive systems of the time.

Braking:

Ventilated front discs, solid rear discs. ABS (Anti-lock Braking System) available on later or higher-spec models.

Restraints:

Seat belts (typically 3-point front, lap rear). Early models may not have airbags. Later models might feature driver airbag.

💡 Technology Features

Audio System:

Factory fitted Clarion or Blaupunkt radios/cassette players, often with basic amplifier systems. Speaker configuration varied by model.

ABS System:

Bosch ABS (2nd generation or earlier) on equipped models.

Power Features:

Power windows, power steering, central locking, electric mirrors were common features across the range.

Climate Control Type:

Manual climate control with A/C, or optional automatic climate control (less common).

🔧 Maintenance

Oil Change Interval:

Typically every 5,000 - 10,000 km or 6-12 months, depending on usage and oil type. Refer to manual for precise recommendation.

Timing Belt Interval:

Crucial maintenance item. Consult manual; often around 50,000 - 80,000 km or 5 years, whichever comes first, due to potential catastrophic failure.

Engine Oil Spec:

Refer to manual: typically a high-quality synthetic or semi-synthetic oil, e.g., SAE 10W-40 or 15W-50, meeting API SH/SJ or equivalent.

Coolant Capacity:

Approx. 8-10 liters (varies by model). Refer to manual for exact capacity.

Brake Fluid Spec:

DOT 3 or DOT 4 (refer to manual for specific recommendation).

Electrical Gremlins:

Known for electrical issues due to wiring complexity and material degradation over time. Faulty relays, sensors, and ECU problems can occur.

Turbocharger Reliability:

Turbochargers and intercoolers can require servicing or replacement due to wear, oil contamination, or heat stress, especially if not maintained properly.

Carburetor Tuning:

Carbureted models require meticulous tuning for optimal performance and emissions.

Rust And Corrosion:

As with many cars of this era, body rust can be a concern, particularly around wheel arches, sills, and the undercarriage. Proper inspection and preventative measures are key.

Timing Belt Part Number:

Refer to manual for exact OE or equivalent P/N (e.g., Gates, Continental). Specific to engine variant.

Oil Filter Part Number:

Refer to manual for exact OE or equivalent P/N (e.g., Fram PH8180, Mahle OC5 for 2.0L variants, specific P/N for other engines).

📚 Vehicle History

Maserati Legacy:

Maserati, founded in 1914, has a rich history in motorsport and luxury grand touring cars, renowned for performance, engineering, and distinctive Italian design.

Biturbo Development:

The Biturbo project was initiated to diversify Maserati's lineup, moving away from exclusive, limited-production models. It aimed to be a more accessible luxury sports car, featuring advanced (for the time) twin-turbo technology.

Platform Strategy:

Developed on a common platform (AM331), with various body styles (Coupe, Spyder) and engine displacements, allowing for cost-effective production and market segmentation.

Manufacturing Location:

Modena, Italy

Production Period:

1981-1994 (though this manual covers the later 1987-1992 iteration).

🏆 Awards & Recognition

Automotive Journalism:

While not a recipient of specific major awards like 'Car of the Year,' the Biturbo models were generally praised for their performance, styling, and value proposition in their segment, though reliability concerns were often noted by contemporary reviews.

Contemporary Reviews:

Reviews often highlighted the potent acceleration from the twin-turbo V6 engines and the engaging driving experience, balanced against occasional build quality and electrical system critiques.