Aftermarket "Engine Performance Tuning" Kits (12 10 08)

AFTERMARKET "ENGINE PERFORMANCE TUNING" KITS

TECHNICAL SERVICE BULLETIN

SERVICE INFORMATION

This Service Information bulletin replaces SI B12 10 08 dated May 2017 

What's New: 

• Diesel engine equipped vehicles added 

New information provided by this revision is preceded by this symbol .

SITUATION

Various aftermarket "Engine Performance Tuning" kits for BMW turbocharged engines are being aggressively advertised to BMW owners.

Depending on the manufacturer, these modifications may consist of a "turbo-tuner control module" (piggyback box) plugged directly into the TMAP sensor/DME/DDE connector, waste-gates vacuum plumbing alterations, or the DME/DDE "performance" software programming.

In general, each aftermarket tuner claims a significant increase in engine power and torque of up to 40% over the stock engine specifications.

These alleged performance gains are achieved by an increase of the turbochargers boost in a wide range of engine speeds, in some cases exceeding the maximum designed turbo pressure by up to 50%.

INFORMATION

None of the aftermarket "Engine Performance Tuning" kits has been evaluated, tested, approved or endorsed by the BMW Development or Service Departments. 

Any alterations to the originally designed and installed turbochargers control system or to the DME software may increase a vehicle's emission levels and may compromise its OBD II compliance.

Moreover, to the best of BMW NA knowledge, none of the aftermarket "Engine Performance Tuning" kits have been certified (homologated) by the appropriate federal and state authorities (EPA/CARB) to meet street-legal emission requirements. BMW vehicles equipped with such "performance enhancement devices" without these certifications are not in compliance with EPA/CARB emission anti-tampering laws.

Excessive turbocharger boost increases engine temperatures resulting in pressures and forces which may damage engine internal components and or may cause premature turbochargers failure.

Due to increased engine output and the altered emissions characteristics, severe damage may be inflicted on emission control components, such as oxygen sensors and catalytic converters.

Excessive engine loads, above the designed levels, may also compromise long term reliability and longevity of other drivetrain components, such as: clutch transmission, automatic transmission torque converter and clutch packs, transfer case, differentials, etc.

WARRANTY INFORMATION

Modification of BMW Vehicles 

Modification of BMW vehicles and/or the installation/attachment of any non-BMW approved performance accessories or components to the vehicle which alters the original engineering and/or operating specifications and/or which results in damage to the original and other vehicle components voids the warranty coverage on the affected original Drivetrain and Emission Control components.

In general terms, the BMW limited warranty for Drivetrain and Emission Control-related "components" is void due to a modification where that modification, alteration or installation of a non-BMW approved aftermarket parts is responsible for the failure.

Please make sure to inform those BMW customers who are considering the purchase and installation of an aftermarket "Engine Performance Tuning" kit on their BMW vehicle of the above warranty, technical and financial-related implications.

Non-Genuine BMW Parts 

While the BMW owner/operator may elect to use non-genuine BMW parts for maintenance or repair services, BMW NA is not obligated to pay for repairs of the non-genuine BMW parts or for repairs of any damage resulting from the use of non-genuine parts.