Market Position:
The Ford Sierra RS Cosworth represented a pinnacle of performance for its era, bridging the gap between potent homologation specials and accessible sports saloons. It was positioned as a driver-focused, high-performance vehicle with rally-bred engineering.
Competitive Analysis:
Competed against other performance saloons of the late 80s and early 90s, such as the BMW M3 (E30), Mercedes-Benz 190E 2.3-16 Cosworth, and various Porsche models. Its aggressive styling and turbocharged engine offered a compelling performance package.
Key Features:
Turbocharged Cosworth YB engine, rear-wheel drive, advanced aerodynamic body kit, sophisticated suspension tuning, and a performance-oriented interior.
Coverage Areas:
All models, engines, trim levels, and transmission types covered for the specified production years.
Page Count:
Extensive, covering all repair procedures A-Z.
Manual Type:
Complete Workshop Service Repair Manual
Format:
Downloadable Digital Format (PDF compatible)
Digital Features:
Searchable text, bookmarking capabilities, ability to zoom in on diagrams, printable pages, and compatibility with various devices (PC, Mac, tablets, smartphones) via Adobe Reader.
Systems Covered:
Engine mechanical, engine management, fuel system, cooling system, lubrication system, exhaust system, ignition system, intake system, transmission (manual and automatic), drivetrain, suspension (front and rear), steering, braking system (including ABS), electrical system (wiring diagrams, components, troubleshooting), body and chassis, interior trim, climate control, diagnostics, and specifications.
Bodywork And Chassis:
Covers body panel alignment, corrosion prevention and repair, chassis structural components, jacking points, and all aspects of the vehicle's exterior and interior trim, including the aerodynamic components specific to the RS Cosworth.
Procedures Included:
Routine maintenance, scheduled servicing, comprehensive troubleshooting, detailed repair procedures, component removal and installation, rebuild procedures, diagnostic tests, wiring diagram interpretation, specifications, adjustments, and technical tips.
Diagnostic Procedures:
Includes guidance on interpreting engine fault codes (if applicable to the era's OBD systems), troubleshooting electrical circuits using multimeters, and systematic diagnostic approaches for various system failures. The manual would cover specific procedures for the Ford EEC-IV engine management system.
Electrical System Repair:
Detailed wiring diagrams for all vehicle systems, component testing, fuse and relay identification, fault finding for lighting, ignition, starting, charging, instrumentation, and accessories.
Technical Depth:
In-depth, suitable for both home mechanics and professional technicians, providing step-by-step instructions with illustrations for all repair and service tasks.
File Format:
PDF (Portable Document Format), compatible with all major operating systems and devices.
Print Quality:
High quality, with clear, legible text and detailed, sharp illustrations and diagrams.
Binding Type:
N/A (Digital Download - Printable)
Paper Type:
N/A (Digital Download - Printable)
Engine Type:
Ford Cosworth YB DOHC Turbocharged Inline-4
Horsepower:
204 PS (150 kW; 201 hp) for early models, increasing slightly in later iterations.
Torque:
275 Nm (203 lb-ft) for early models, with later models seeing increases.
Fuel System:
Electronic Fuel Injection (EFI) with a Garrett T3 turbocharger and intercooler.
Turbocharger Details:
Garrett T3 Turbocharger with wastegate control and an air-to-air intercooler. Specifications for turbocharger inspection and rebuild are likely included.
Engine Codes:
YB (various sub-codes depending on specific production phase and market)
Engine Displacement:
2.0 Litres (1993 cc)
Wheelbase:
Approx. 2600 mm (102.4 inches)
Length:
Approx. 4435 mm (174.6 inches)
Width:
Approx. 1705 mm (67.1 inches)
Height:
Approx. 1390 mm (54.7 inches)
Curb Weight:
Approx. 1260 kg (2778 lbs)
Safety Ratings:
Euro NCAP ratings were not standard for vehicles of this era; however, the Sierra range underwent various safety updates throughout its production.
Active Features:
Anti-lock Braking System (ABS) was a common and significant safety feature, especially on performance models like the RS Cosworth.
Passive Features:
Seat belts (front and often rear), collapsible steering column, reinforced passenger cell, and energy-absorbing crumple zones. Early models may lack airbags as standard.
Infotainment System:
Basic by modern standards. Typically featured an AM/FM radio with cassette player, often with amplifier and upgraded speaker systems. Digital displays were limited.
Driver Assistance Features:
Limited. ABS was the primary active driver aid. Features like traction control were not standard on early models, though some later iterations or aftermarket additions might exist. Cruise control was an option on some trims.
Connectivity Options:
None by modern standards. No Bluetooth, USB, or integrated navigation.
Oil Change Interval:
Typically every 5,000 - 7,500 miles (8,000 - 12,000 km) or 6-12 months, depending on driving conditions and oil type used. Refer to manual for specific recommendations.
Spark Plug Replacement:
Dependent on spark plug type (e.g., copper, platinum, iridium), usually between 15,000 - 30,000 miles (24,000 - 48,000 km).
Timing Belt Replacement:
Crucial interval, typically 36,000 miles (58,000 km) or 3 years. Failure to replace can result in catastrophic engine damage due to the interference nature of the YB engine.
Engine Oil Specification:
API SG/SH or ACEA A2/A3, viscosity grades such as 5W-30, 5W-40, or 10W-40 depending on ambient temperature. Consult manual for precise recommendations.
Coolant Specification:
Ford Super Plus Premium Coolant or equivalent (Ethylene Glycol based, typically 50/50 mix with distilled water). Specific Ford part numbers would be detailed in the manual.
Transmission Fluid Type:
Manual transmission: SAE 75W-90 or 75W-80 GL-4 or GL-5 gear oil. Automatic transmission (if applicable to other Sierra models): Mercon V or equivalent.
Brake Fluid Specification:
DOT 3 or DOT 4 brake fluid.
Power Steering Fluid:
Ford specification power steering fluid or equivalent, likely Dexron II/III compatible for early models.
Common Issues:
Head gasket failure on early YB engines, turbocharger wear, ignition system issues (coil packs, distributorless ignition), suspension bush wear, rust on sills and wheel arches, and electrical gremlins due to age. Timing belt replacement is critical.
Common Issues Details:
The Cosworth YB engine, while robust, is sensitive to maintenance. Overheating can lead to head gasket issues. Turbocharger seals can degrade with age and heat. Performance modifications without commensurate upgrades can lead to premature component failure. The manual would provide diagnostics for these common ailments.
Brand Heritage:
Ford's history in motorsport is extensive, and the Cosworth name is synonymous with high-performance engines and engineering prowess, particularly in rallying and touring car racing.
Model Evolution:
The Sierra RS Cosworth was developed to homologate the Sierra for Group A touring car racing. It was initially released in 1986 as a 2WD model, followed by the Sierra RS500 Cosworth (a more potent, homologation special) and later, the Sierra Sapphire RS Cosworth 4x4 model introduced in 1990. The RS Cosworth variant was a significant departure from the standard Sierra, focusing purely on performance.
Production Years:
1985-1993 (Sierra range), with the RS Cosworth variants produced between 1986 and 1992.
Production Locations:
Ford-Werke GmbH in Germany (for initial Sierra production) and later in the UK at Ford's advanced manufacturing facilities for specific RS models. Some components were produced by Cosworth.
