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SI M11 02 13
Engine

August 2016
Technical Service

ENGINE OIL CONSUMPTION

This Service Information bulletin supersedes SI M11 02 13 dated November 2014.
MODEL

All
INFORMATION

All engines consume a certain amount of engine oil. This is necessary in order to properly lubricate
the cylinder walls, pistons, piston rings, valves and if equipped, the turbocharger(s).
In addition, engines with less than 10,000 miles will generally consume additional engine oil
because the internal engine components are not fully seated (break-in). Therefore engine oil
consumption analysis should be performed after this break in period.
Once a new or remanufactured engine has accumulated 10,000 miles, oil consumption can be
considered if there is a drastic change in the engine oil consumption rate (e.g., the engine oil
consumption rate triples) under similar driving conditions.
Engines equipped with a turbocharger(s) will consume more engine oil than normally aspirated
engines (non-turbocharged). The additional oil that is consumed in a turbocharged engine is mainly
due to the turbocharger lubrication requirements. Some of the engine oil normally migrates past the
turbocharger turbine bearing seals and will enter the intake tract of the engine. All turbocharged
engines also require a complex crankcase ventilation system. The crankcase ventilation system
needs to maintain a small vacuum on the crankcase and not allow the crankcase to be pressurized.
Pressurizing the engine crankcase can lead to external engine oil leaks and increased engine oil
consumption via the piston rings and valve seals. When the load and the boost level of a
turbocharged engine is varied, the path of the crankcase pressure is changed. During the crankcase
ventilation path transition, a small amount of engine oil will pass through the crankcase ventilation
system and is additionally consumed. Oil residue found in these crankcase ventilation hoses is a
normal condition for a properly operating turbocharged engine. The additional engine oil
consumption of a turbocharged engine, as compared to a normally aspirated engine, is normal and
not a defect.
OIL CONSUMPTION SPECIFICATION

Engine type:

Oil Consumption Specification:

All MINI B36, B38, B46 and B48 engines

1 liter per 1,500 miles

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All MINI W10, W11, N12, N14, N16 and
N18 engines

1 liter per 750 miles

DIAGNOSTIC HINTS

When an oil consumption complaint is received, it may be possible to correct it without performing
extensive engine repairs. Check the following frequent causes of excessive oil consumption prior to
undertaking any engine consumption analysis or repairs.
Proper Maintenance
Has the vehicle received proper maintenance? Certain external conditions (mainly city driving style
and/or high engine loads; poor fuel quality; and extreme ambient temperatures), combined with
excessively long oil service intervals may accelerate engine oil degradation, which may cause
premature wear of the engine components. Continuous city driving and very high ambient
temperatures are the most influential factors causing premature oil aging and consequential engine
mechanical deterioration.
External Leakage
The engine should be leak-free before starting any engine oil consumption analysis.
Overfilling
If the oil level is too high, oil in the crankcase will be thrown against the cylinder walls and
consumed. Check the dipstick markings or electronic measurement (as equipped) to be sure of
accuracy. The oil level must not be higher than the upper mark.
Engine Oil Viscosity/Quality
The use of oil with the wrong viscosity rating for the operating conditions can cause high oil
consumption. Check the Owner's Manual or SI M11 01 15 to determine the proper viscosity for the
conditions.
Engine Speed and Load
If vehicle operating conditions are severe, oil consumption will be higher than normal. Extreme
load, continuous high engine speed or long idling times in traffic will result in increased oil
consumption.
Crankcase Ventilation
The crankcase ventilation systems use various different crankcase ventilation valves, depending on
the engine type. Although the valves all look different, they function similarly, using a spring and
diaphragm assembly to control the crankcase pressure. A properly functioning pressure control
valve is designed to maintain a slight vacuum (under-pressure) in the crankcase, which assures
reliable crankcase venting during all engine operating conditions. One of the results of a
malfunctioning crankcase ventilation system can be increased engine oil consumption. Refer to SI

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M11 07 08 for measuring specifications and procedures.
Turbocharged Engines
Engines that are fitted with a turbocharger(s) will consume more engine oil than naturally aspirated
engines (non-turbocharged engines). In this case, a turbocharged engine could require topping up of
engine oil more frequently. For vehicles with turbocharged engines, refer to the attachment to help
identify a turbocharger with acceptable oil leakage.
M110213_Acceptable_Turbocharger_Oil_Leakage_8_5_2016
MEASURING OIL CONSUMPTION

These measurements should only be considered after all of the points above have been reviewed.
When a customer complaint of engine oil consumption is received, the engine oil must be drained,
measured and the engine oil refilled.
The vehicle must be driven 1,000 miles or until the next low engine oil message appears
(whichever comes first). The oil must be drained again and measured to identify consumption level.
Always refer to ISTA/D or SI M11 01 15 for the recommended oil type and the amount required,
using the VIN number of the vehicle.
Use the attached oil consumption checklist to document the vehicle information, current engine
condition and oil consumption results. Work through the checklist to set up the oil consumption
test. If part 1 exceeds the allowable oil consumption for that engine variant then proceed to part 2 to
complete the diagnosis.
MINI_Oil_Consumption_Checklist_8_5_2016
WARRANTY INFORMATION

Not Applicable.
ATTACHMENTS

View PDF attachment M110213_Acceptable_Turbocharger_Oil_Leakage_8_5_2016.
View PDF attachment M110213 MINI_Oil_Consumption_Checklist_8_5_16.
[ Copyright ©2016 BMW of North America, Inc. ]

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