2013 maintenance schedule
2013 BMW 335is Convertible Service Schedule & Maintenance Guide
The 2013 BMW 335is Convertible is equipped with the Condition Based Service (CBS) system.
Last updated
September 22, 2026
Reviewed for service schedule clarity.
Key Takeaways
- CBS System: The 2013 BMW 335is Convertible (E93) uses the Condition Based Service (CBS) system, which uses sensors and algorithms to determine maintenance needs based on actual driving conditions rather than a fixed schedule . For major periodic service, BMW generally recommends service every 2 years or after 30,000 kilometers (approximately 18,600 miles) .
- Engine & Performance: The 335is is powered by the N54 twin-turbo 3.0-liter inline-six engine, featuring an overboost function that increases torque to 370 lb-ft on demand. The vehicle is equipped with BMW's M Sport package, upgraded cooling, and an M Sport exhaust system.
- Oil Change: Pelican Parts recommends changing synthetic motor oil every 5,000 miles . The engine's oil capacity is approximately 7 quarts with filter .
- Oil Specification: The N54 engine requires synthetic oil meeting BMW Longlife-01 approval. Genuine BMW TwinPower Turbo 0W30 is recommended by BMW, with options including 5W-30 and 5W-40 . Always refer to your owner's manual for the correct viscosity for your climate.
- Spark Plugs: BMW specifies spark plug replacement at 45,000 miles for the 335is—a shorter interval than standard 335i models (60,000 miles) . For tuned or modified vehicles, COBB Tuning recommends replacing spark plugs and coil packs every 30,000 miles .
- Brake Fluid: BMW recommends changing the brake fluid every 2 years regardless of mileage .
- Carbon Cleaning: The N54's direct-injection design can lead to carbon buildup on intake valves; cleaning (walnut blasting) may be needed as early as 25,000 miles depending on driving conditions .
Understanding BMW's Condition Based Service (CBS) System
The 2013 BMW 335is Convertible is equipped with the Condition Based Service (CBS) system. This system uses sensors and special algorithms that take into account the driving conditions of your vehicle to recognize maintenance requirements and adapt them to your specific driving profile .
How CBS Works:
- Sensors and algorithms monitor your driving style, trip length, and operating conditions to determine when service is needed
- Service requirements can be displayed on the Control Display
- Information on required maintenance is continuously stored in your remote control key
- For major periodic service, BMW recommends this be done every 2 years or after 30,000 kilometers (approximately 18,600 miles)
Storage Periods: Storage periods during which the vehicle battery was disconnected are not taken into account by the CBS system . If this occurs, have a service center update time-dependent maintenance procedures such as checking brake fluid .
Engine Oil Service
BMW Factory Schedule
The CBS system determines the precise oil change interval based on your driving conditions.
Oil Specifications
The N54 engine requires synthetic motor oil. Pelican Parts recommends changing synthetic motor oil every 5,000 miles and always replacing the filter when changing the oil .
Approved oils must meet BMW Longlife-01 approval . Recommended options include:
- Genuine BMW TwinPower Turbo 0W30
- 5W-30 Fully Synthetic Long Life
- 5W-40 Fully Synthetic Long Life
Oil Capacity: Approximately 7 quarts (6.6 liters) with filter . A 7-liter oil change package is common for Inspection I service on the N54/N55 engine .
Oil Filter: Use OEM or OEM-equivalent (Mahle, Mann, or BMW) filters. The Mahle oil filter kit includes the filter, two cap o-rings, and a drain plug crush seal . An oil filter housing cap tool is recommended for filter access .
Owner Guidance
Motor oil is the single most important element in keeping your engine healthy and helping it to enjoy a long life . For the 335is's high-performance N54 engine, independent specialists recommend a conservative oil change interval of 5,000 miles . For vehicles driven aggressively, COBB Tuning recommends being aggressive with all factory recommended maintenance intervals .
Spark Plug & Ignition System Service
BMW Factory Schedule
Critical difference for the 335is: BMW specifies spark plug replacement at 45,000 miles for the 335is, Z4 sDrive35i, and Z4 sDrive35is—versus 60,000 miles for the standard 335i .
Owner Guidance
For tuned or modified vehicles, COBB Tuning recommends replacing spark plugs and ignition coil packs every 30,000 miles in order to sustain peak performance with an aftermarket calibration .
Misfire Diagnosis: If the vehicle is exhibiting random or constant misfiring, check the following:
- Fuel pump and injectors (early production cars)
- Condition of the spark plugs
- Carbon buildup on the backs of intake valves
Brake Fluid Service
BMW Factory Schedule
BMW recommends changing the brake fluid every 2 years regardless of mileage . A BMW manual also indicates that brake fluid should be changed every two years .
Specification
The 2013 BMW 335is Convertible requires DOT4 specification brake fluid.
N54 Engine Carbon Build-Up (Walnut Blasting)
The N54 engine is direct-injected, which can cause carbon deposits to accumulate on intake valves. This can lead to performance degradation, rough running, and misfires .
Key Points:
- Carbon cleaning may be needed as early as 25,000 miles
- All cases differ in terms of severity of buildup
- Physical inspection requiring removal of the intake manifold is needed to assess buildup
- Recommended cleaning method is walnut blasting
- Dealerships may charge upwards of $1,000 for this service
Transmission Service
BMW Factory Schedule
For automatic transmissions, BMW designates the fluid as "lifetime fill" for normal operation, with no specified replacement interval. However, the 335is may feature BMW's optional M-DCT (Dual Clutch Transmission) on some models, which has different service requirements .
Owner Guidance
Automatic transmission fluid and filter changes at recommended intervals remove harmful abrasives and corrosive chemicals that can damage expensive drivetrain components . For DCT-equipped vehicles, more frequent fluid service may be recommended.
45,000-Mile Major Service
The 45,000-mile service for the 2013 BMW 335is is a critical maintenance milestone. Based on OEM documentation, this service includes :
| Service Item | Action | Notes |
|---|---|---|
| Spark Plugs | Replace | 45,000-mile interval for 335is |
| Brake Fluid | Flush/Replace | If not done at 2-year interval |
| Engine Oil & Filter | Replace | As indicated by CBS |
| Air Filter | Inspect/Replace | As indicated by CBS |
| Vehicle Check | Perform | Comprehensive inspection |
100,000-Mile Service
At 100,000 miles, BMW recommends :
| Service Item | Action |
|---|---|
| Automatic Transmission Fluid | Change |
| Oxygen Sensor | Replace |
General Service Recommendations Summary
The CBS system is the ultimate authority for your specific vehicle. The following table summarizes key service intervals based on OEM documentation and specialist guidance:
| Service Item | OEM/General Guidance | Conservative Guidance |
|---|---|---|
| Major Periodic Service | Every 2 years or 30,000 km | Follow manufacturer schedule |
| Engine Oil & Filter | CBS-driven | Every 5,000 miles |
| Brake Fluid | Every 2 years | Follow manufacturer schedule |
| Spark Plugs (335is) | 45,000 miles | Every 30,000 miles (modified vehicles) |
| Engine Air Filter | Every 36,000 miles | Inspect regularly |
| Automatic Transmission Fluid | 100,000 miles | Consider earlier service |
| Oxygen Sensor | 120,000 miles | Follow manufacturer schedule |
| Carbon Cleaning | As needed | Inspect at 25,000+ miles |
Frequently Asked Questions
1. How often should I change the oil in my 2013 BMW 335is Convertible?
Pelican Parts recommends changing synthetic motor oil every 5,000 miles and always replacing the filter when changing the oil . For tuned vehicles, COBB Tuning recommends being aggressive with all factory recommended maintenance intervals .
2. What oil does the 2013 BMW 335is Convertible require?
The N54 engine requires synthetic oil meeting BMW Longlife-01 approval . Genuine BMW TwinPower Turbo 0W30 is recommended, with 5W-30 and 5W-40 also available options . Refer to your owner's manual for the correct viscosity for your climate.
3. When should the spark plugs be replaced?
Critical: BMW specifies spark plug replacement at 45,000 miles for the 335is—a shorter interval than the 60,000-mile interval for the standard 335i . For modified vehicles, COBB Tuning recommends replacement every 30,000 miles .
4. When should the brake fluid be replaced?
BMW recommends changing the brake fluid every 2 years regardless of mileage . The vehicle requires DOT4 brake fluid.
5. What is the Condition Based Service (CBS) system?
The CBS system uses sensors and algorithms to monitor driving conditions and determine service needs. For major periodic service, BMW recommends this be done every 2 years or after 30,000 kilometers . Service information is stored on your remote control key .
6. Does the 2013 BMW 335is Convertible use a timing belt or timing chain?
The N54 engine uses a timing chain designed for the life of the engine. Regular oil changes are critical for chain longevity.
7. What is carbon build-up, and does it affect my 335is?
The N54 engine is direct-injected, which can cause carbon deposits on intake valves. This may require cleaning (walnut blasting) as early as 25,000 miles, depending on driving conditions . Dealerships charge upwards of $1,000 for this service .
8. What is the oil capacity of the N54 engine?
The N54 engine has an oil capacity of approximately 7 quarts (6.6 liters) with filter . A 7-liter oil change package is common for the N54/N55 engine .
9. What is the 100,000-mile service for the 335is?
The 100,000-mile service includes changing the automatic transmission fluid and replacing the oxygen sensor .
10. Is the 2013 BMW 335is Convertible expensive to maintain?
Maintenance costs are above average for non-luxury vehicles but typical for premium high-performance German cars. The 335is has specific maintenance considerations including more frequent spark plug replacement and potential carbon cleaning. Regular preventative maintenance is key to extending the life of the vehicle.
*Always consult your vehicle's owner's manual and CBS system for the most accurate maintenance requirements for your specific 2013 BMW 335is Convertible. Maintenance needs may vary by production date and driving conditions.*