B4x Servicing & Maintenance Information
Please take this advice as general in nature and choose what best works for you and your situation.
B4x Performance Recommended Service Intervals
| Service Item | Interval |
|---|---|
| Engine Oil | 10,000 KM or 5,000 KM if using Ethanol Fuels regularly |
| Transmission (Auto) Oil | 80,000 KM |
| Transmission (Manual) Oil | 50,000 KM |
| Transmission Oil Aisin AWF8F45 (B48E) | 30,000 KM |
| Differential Fluid | 50,000 KM |
| Transfer Case Fluid | 50,000 KM |
| Spark Plugs | OEM Gap 50,000 KM (Do Not Gap Plugs) |
| Coil Packs | 80,000 KM |
| Injectors | 80,000 KM |
| Coolant | 85,000 KM |
| Brake Fluid | 50,000 KM |
| Brake Pads | 50,000 KM or When Indicator Lamp Is Active |
| Intake Filter | 50,000 KM |
| Cabin Filter | 30,000 KM |
| Accessories Belt | 100,000 KM |
| Fuel Filter (If Present) | 50,000 KM |
Preventative Maintenance / Common Failure Points
Charge Pipes
Stock units are known to crack and leak under boost with age/heat-cycles.
Turbo Inlet
Stock units are known to crack.
Catch Cans
Oil Catch Can helps eliminate carbon/sludge build up within the cylinder head/intake valves and clean the intake/charge air system from oil and contaminates.
Pistons
Cast pistons can be fragile in nature. It's important to ensure the tune does not run too lean as this causes the piston rings to fail or pistons to crack.
HPFP
These pumps can fail at delivering correct amounts of fuel when tuned incorrectly or running exotic fuels such as ethanol that exceed the flow capacity of the pump. When the pump begins to fail, AFRs go lean causing piston/engine damage.
Understanding BMW LL Oil Ratings
BMW LL (Long Life) oil ratings are specifications set by BMW for engine oils to ensure optimal performance and longevity. BMW B4x engines are compatible with all LL ratings.
Using non-LL based oils can pose significant risks since these oils have not been validated for use in BMW engines and should be avoided. Always use oils that carry at minimum a BMW LL certification.
Recommended Engine Oils
Understanding Oil Weight Classifications
Multi-grade oils are rated with two numbers separated by a W (e.g. 5W-30). The W stands for Winter and refers to the oil's viscosity at cold temperatures.
- •First number (e.g. 0W, 5W, 10W) — The oil's cold temperature viscosity grade. Lower numbers mean the oil is thinner and flows more easily when cold. A 0W oil has lower viscosity at cold temperatures than a 10W, meaning it circulates faster through the engine on a cold morning.
- •Second number (e.g. 30, 40, 60) — The oil's viscosity at operating temperature (100°C). Higher numbers mean a thicker oil film at temperature, providing greater protection under load and at higher temperatures.
Example: A 5W-30 has the cold viscosity of a 5-weight oil, allowing it to flow and circulate quickly when cold, while maintaining the thickness of a 30-weight oil at 100°C. A 0W-30 would have even lower cold viscosity but the same oil film thickness at operating temperature.
Note: The oil weights below will not always be 100% what you may need if you have had an engine rebuild. In this case, refer to your engine builder on what oil weight you should run based on your main and rod bearing clearances.
For Extreme Racing Applications
| Weight | Brand | Compliance |
|---|---|---|
| 10W-60 | Shell Helix Ultra Racing | A3/B4, BMW M Approved |
| 10W-60 | Castrol EDGE Supercar | A3/B4, BMW M Approved |
| 5W-40 | Motul 300V Power | A3/B4, Ester Core |
| 5W-40 | Red Line Racing Oil | A3/B4 |
| 5W-30 | Penrite Racing 5 | A3/B4, LL-98 |
| 5W-30 | Liqui Moly Special Tec B FE | A3/B4, LL-01FE |
For Most Climates
| Weight | Brand | Compliance |
|---|---|---|
| 5W-30 | Castrol EDGE | A3/B4, LL-01 |
| 5W-30 | LIQUI MOLY Special Tec | A3/B4, LL-01 |
| 5W-30 | Pennzoil Platinum Euro | A3/B4, LL-01 |
| 5W-30 | MOTUL 8100 X-CESS | A3/B4, LL-01 |
| 5W-30 | RAVENOL RSP | A3/B4, LL-01 |
| 5W-30 | Shell Helix Ultra | A3/B4, LL-01 |
| 5W-30 | Penrite Racing 5 | A3/B4, LL-98 |
For Very Cold Climates
| Weight | Brand | Compliance |
|---|---|---|
| 0W-30 | Castrol Edge | A3/B4, LL-01 |
| 0W-30 | Penrite HPR 0 | A3/B4, LL-01 |
For B4x/B4xTU with GPF/OPF
| Weight | Brand | Compliance |
|---|---|---|
| 5W-30 | Motul Specific | A3/B4, LL-01FE |
| 5W-30 | Liqui Moly Special Tec B FE | A3/B4, LL-01FE |