2014 BMW 640i Convertible Maintenance Schedule & Service Intervals

Key Takeaways

• The 2014 BMW 640i Convertible (F12 chassis) is powered by the N55 3.0L turbocharged inline-six engine and features a retractable hardtop roof.
• BMW utilizes a Condition Based Service (CBS) system that calculates maintenance needs based on actual driving conditions rather than fixed intervals. Service data is stored in the vehicle's remote key fob .
• Major periodic service is generally recommended every 2 years or after 30,000 kilometers (approximately 18,600 miles) .
• Brake fluid requires replacement every 2 years regardless of mileage—this is a critical time-based safety requirement .
• A conservative synthetic oil change interval recommended by independent specialists is 5,000 miles for optimal engine longevity .
• The N55 engine uses Bosch spark plugs as original equipment .
• The serpentine drive belt, tensioner, and pulleys should be replaced approximately every 80,000 miles .

Understanding BMW's Condition Based Service (CBS) System

The 2014 BMW 640i Convertible utilizes BMW's Condition Based Service (CBS) system. Unlike traditional fixed-interval maintenance schedules, CBS uses sensors and algorithms that take into account the driving conditions of your vehicle to determine when maintenance is required . The system adapts the amount of maintenance to your specific driving profile, considering factors such as trip length, engine temperature, and driving style.

Service Data in the Remote Control: Information on required maintenance is continuously stored in the remote key fob. Your service center will read this data and suggest the appropriate service procedures for your vehicle.

For major periodic service, this should generally be done every 2 years or after 30,000 kilometers (approximately 18,600 miles) .

OEM Factory Maintenance Schedule

The following maintenance intervals represent the recommended schedule for the 2014 BMW 640i Convertible. Exact intervals are determined by the vehicle's CBS system based on driving conditions.

Engine Oil and Filter Change

The 2014 640i Convertible uses the N55 3.0L turbocharged inline-six engine. BMW's CBS system will indicate when an oil service is due, with typical intervals around 10,000 miles or 12 months depending on driving conditions.

Oil Specifications:

• BMW-approved synthetic oil meeting BMW Longlife specifications
• Oil meeting BMW LL-01 approval is suitable for this engine
• The specific viscosity should be selected based on climate and driving conditions as specified in your owner's manual

Conservative Owner Guidance:

Motor oil is the single most important element in keeping your engine healthy . Independent specialists recommend changing synthetic motor oil every 5,000 miles for optimal engine protection . Always replace the oil filter when changing your oil. More frequent changes are advisable if you regularly engage in aggressive driving, operate in dusty conditions, or make frequent short trips.

Brake Fluid Service

Brake fluid service is a critical safety item. BMW recommends changing the brake fluid every 2 years regardless of mileage .

Fluid Specification:

• BMW-approved brake fluid
• DOT4 specification is appropriate for this vehicle

Owner Guidance:

Brake fluid is a hydraulic fluid specially formulated to withstand the extreme pressures and temperatures of your braking system. Brake fluid should be changed every time you service your brakes . Check your owner's manual for your vehicle's particular brake fluid specifications . BMW generally recommends that brakes be inspected and serviced at least once every 12,000 miles or 12 months.

Serpentine Drive Belt Service

The N55 single-turbo engine uses a serpentine drive belt to operate the steering pump, AC compressor, and alternator.

Recommended Interval: The belt, along with the tensioner and pulleys, should be replaced approximately every 80,000 miles .

Service Kit: A complete drive belt service kit is recommended for this procedure, which includes all necessary OEM components for a factory-quality replacement. The kit for the 2014 BMW 640i Convertible includes :

• Main drive belt (1,478mm)
• Drive belt tensioner
• Tensioner mounting bolt
• Deflection pulley
• Deflection pulley

Spark Plug Service

The N55 engine uses high-performance spark plugs to ignite the fuel-air mixture in the combustion chamber.

OEM Part: The 2014 BMW 640i Convertible uses Bosch spark plugs as original equipment .

Owner Guidance:

Keeping your spark plugs fresh is a very important part of keeping your car in top shape . Check for abnormal pitting or charred plug ends when replacing. Any strange variations among plugs are a sure indicator that something is wrong with a particular cylinder .

Wheel Bearing Maintenance

Wheel bearing grease lubricates the bearings that support the weight and heat generated by the spinning of the wheels .

Conservative Guidance: It is a good idea to clean and repack wheel bearings once a year as preventive maintenance . High-temperature service grease is recommended for rolling bearings.

Ignition Coils

Although ignition coils are not typically considered a scheduled maintenance item, they may require replacement if they fail.

Owner Guidance: Ignition coils should be replaced as a full set when any individual coil fails . A faulty ignition coil can mean an engine that has a hard time starting or one that is mistimed when it needs the spark in the combustion chamber, which can reduce engine performance and cause undue wear and tear .

BMW Maintenance Program Coverage

For the 2014 model year, BMW offered standard maintenance program coverage from the original in-service date. For vehicles beyond this coverage, owners should plan for out-of-pocket maintenance.

Long-Term Ownership Outlook

With proper and diligent maintenance, the 2014 BMW 640i Convertible can achieve high mileage. The N55 engine is a reliable powerplant when properly maintained. Staying on track with routine service appointments helps maintain performance, safety, and resale value.

The convertible top mechanism, while not requiring specific service intervals, should be inspected periodically for proper operation and seal condition. Regular oil level monitoring through the iDrive system is important for turbocharged engines like the N55.