2009 BMW M6 Convertible Service Schedule & Maintenance Guide

Key Takeaways

• The 2009 BMW M6 Convertible (E64) is powered by the legendary S85 5.0L naturally aspirated V10 engine, producing 500 hp at 7,750 rpm. This F1-derived engine demands meticulous and specific maintenance, including BMW-approved 10W-60 oil and regular spark plug changes.
• BMW Ultimate Service provides complimentary scheduled maintenance for 4 years or 50,000 miles from the original in-service date, covering factory-recommended service as determined by the Condition Based Service (CBS) system .
• The S85 V10 engine requires a high-quality synthetic oil meeting BMW Longlife-01 (LL-01) or LL-04 specifications, with 10W-60 being the preferred viscosity. Independent specialists recommend changing the oil every 5,000 miles for optimal protection .
• Spark plugs require replacement every 30,000–40,000 miles on this high-performance V10 engine . The engine uses ten individual spark plugs.
• Brake fluid requires replacement every 2 years, as it is a safety-critical, time-based service .
• Rod bearings are a known wear item on the S85 engine. Many independent specialists recommend proactive replacement between 60,000 and 80,000 miles to prevent catastrophic engine failure .

Understanding the 2009 BMW M6 Convertible (E64 Generation)

The 2009 BMW M6 Convertible is part of the E64 generation, powered by the legendary S85B50 5.0L naturally aspirated V10 engine. This engine is a milestone in BMW's history, derived from Formula 1 technology and producing 500 horsepower at 7,750 rpm and 383 lb-ft of torque at 6,100 rpm . Its high-revving, high-compression design demands meticulous maintenance.

The Condition Based Service (CBS) System

The 2009 M6 employs BMW's Condition Based Service (CBS) system. Sensors and special algorithms take into account the driving conditions of your vehicle—including engine temperature, driving style, trip length, and component wear—to determine maintenance requirements. The system adapts the amount of maintenance to your individual driving profile.

Service notifications appear on the Control Display when maintenance is due. This adaptive approach means your M6 may require service at different intervals than another vehicle of the same model, depending entirely on how it is driven.

Never ignore CBS alerts. Prompt attention to service notifications prevents minor issues from developing into costly repairs.

BMW Ultimate Service & Warranty Coverage

The 2009 BMW M6 Convertible included BMW Ultimate Service, which provided complimentary scheduled maintenance for 4 years or 50,000 miles from the vehicle's original in-service date . Coverage included engine oil and filter changes, brake fluid flushes, spark plug replacements, and vehicle checks.

Scheduled Maintenance Intervals

The following intervals represent factory-specified guidance for the 2009 BMW M6 Convertible . The CBS system remains the definitive authority for your specific vehicle's needs.

General BMW Maintenance Guidance

Based on available sources and the S85 engine's known requirements:

• Synthetic Oil and Filter Changes: Typically determined by the CBS system, but independent specialists strongly recommend 5,000-mile intervals for optimal engine protection.
• Spark Plugs: Recommended at 30,000–40,000 mile intervals.
• Brake Fluid: Required every 2 years.
• Cooling System: Flush and refill with BMW-approved coolant every 2 years.

Engine Oil Service: The Lifeline of the S85 V10

Factory Guidance

The S85 V10 engine requires high-quality synthetic engine oil meeting BMW's specific Longlife-01 (LL-01) or LL-04 specifications . The recommended viscosity is typically 10W-60, which is engineered to handle the high temperatures and tight tolerances of this high-revving engine .

Oil Capacity: Approximately 9.5 liters.

Conservative Owner Guidance

Motor oil is the single most important element in keeping your engine healthy . While the CBS system may suggest intervals, independent specialists strongly recommend more frequent oil changes for the S85 engine:

• Pelican Parts recommends changing synthetic motor oil every 5,000 miles
• Willand Service Centre recommends 5,000–7,500 miles, particularly for severe driving conditions
• For track use or aggressive driving, consider even shorter intervals

Signs that an oil change may be needed sooner include:

• Engine knocking sounds
• Oil smell inside the vehicle
• Frequent dusty road driving, heavy loads, or low-speed driving for long distances

Spark Plugs

Factory Guidance

The 2009 BMW M6's S85 V10 engine requires spark plug replacement every 30,000–40,000 miles . The engine uses ten spark plugs—one per cylinder.

Worn spark plugs can lead to misfires, rough idling, and reduced power. Given the individual throttle bodies of the S85, precise ignition timing is paramount.

Symptoms of Worn Spark Plugs

• "Engine Fault" codes that may seem intermittent
• Reduced performance
• Increased emissions
• Rough idle

Brake Fluid

Factory Guidance

Brake fluid replacement is a safety-critical, time-based service. BMW recommends replacing brake fluid every 2 years . The 2009 M6 Convertible requires high-performance DOT 4 specification brake fluid.

Importance

Brake fluid is hygroscopic—it absorbs moisture from the atmosphere over time. This moisture accumulation lowers the fluid's boiling point, which can lead to brake fade during spirited driving. A spongy brake pedal is a key symptom of contaminated fluid .

Differential & Transmission Fluid

Factory Guidance

Based on BMW service documentation for the E64 M6, the rear axle differential oil should be replaced with each third engine oil change . The transmission oil (SMG or manual) follows the same pattern—first replaced at the 1,200-mile break-in service, then with each third engine oil change .

These services are critical for the longevity of the drivetrain. The Active M Differential requires fresh fluid to maintain proper cooling and friction characteristics.

Cooling System

Factory Guidance

The S85 V10 generates significant heat, making a robust cooling system essential. BMW recommends:

• Coolant flush and refill every 2 years using BMW-approved coolant mixed with distilled water
• Regular inspection of the water pump, thermostat, and hoses

The electric water pump is a known weak point on the E60/E63/E64 M6. Early detection of a failing pump (e.g., erratic temperature readings, coolant leaks) is crucial .

Rod Bearings: The Critical S85 Consideration

Enthusiast Guidance

The S85 V10 engine has a well-documented vulnerability regarding its rod bearings. BMW's original bearings and oil clearances were insufficient for the high-revving design, requiring replacements every 60,000–80,000 miles .

Independent specialists and aftermarket suppliers offer replacement bearings designed with extra clearance to address this flaw. Many enthusiasts consider rod bearing replacement a mandatory preventive service on higher-mileage S85 engines.

Recommended Replacement Interval: Between 60,000 and 80,000 miles .

Symptoms of Failing Rod Bearings:

• Metallic knocking sounds from the engine, especially at cold start
• Metal particles in the oil filter
• Low oil pressure warnings

Long-Term Ownership Considerations

S85 Engine-Specific Maintenance

The S85 V10 is a masterpiece of engineering but has several well-documented maintenance requirements that owners must respect :

• VANOS System: The variable valve timing system may require periodic inspection and replacement of solenoids and seals at higher mileages.
• Throttle Actuators: The electronic throttle actuators are a common failure point on higher-mileage examples, often leading to "limp mode."
• Cooling System: Overhauling the water pump, thermostat, and hoses at regular intervals is essential to prevent overheating.
• SMG Transmission: If equipped, the SMG hydraulic system requires regular service; some owners consider converting to a manual gearbox for improved reliability.

High-Mileage Maintenance Planning

For owners accumulating significant mileage:

• 60,000-80,000 Miles: Rod bearing replacement (preventive)
• 100,000+ Miles: Full cooling system overhaul, VANOS service, throttle actuator inspection

Frequently Asked Questions

Does the 2009 BMW M6 Convertible have a fixed maintenance schedule?

The 2009 M6 uses BMW's Condition Based Service (CBS) system, which monitors actual driving conditions to determine service intervals. However, a traditional mileage-based schedule is also recommended for critical components .

What engine is in the 2009 BMW M6 Convertible?

The 2009 BMW M6 Convertible is powered by the S85B50 5.0L naturally aspirated V10 engine, producing 500 horsepower at 7,750 rpm .

What oil does the 2009 BMW M6 Convertible use?

The S85 V10 requires BMW-approved synthetic oil meeting LL-01 or LL-04 specifications, with 10W-60 being the recommended viscosity . Pelican Parts recommends changing the oil every 5,000 miles .

How often should spark plugs be replaced on the 2009 BMW M6?

BMW recommends spark plug replacement every 30,000–40,000 miles . The engine requires 10 spark plugs.

How often does brake fluid need replacing in the 2009 BMW M6?

BMW recommends brake fluid replacement every 2 years . This is a safety-critical, time-based service.

When should the differential fluid be changed?

The differential fluid should be replaced with each third engine oil change . The same schedule applies to the transmission oil.

When should rod bearings be replaced on the S85 engine?

Rod bearings are a known wear item on the S85 V10 engine. Independent specialists recommend proactive replacement between 60,000 and 80,000 miles as a preventive measure .

What was the warranty coverage for the 2009 BMW M6 Convertible?

The 2009 BMW M6 Convertible included a 4-year/50,000-mile new vehicle warranty and BMW Ultimate Service with 4 years/50,000 miles of complimentary scheduled maintenance .