The issue is down to the high-pressure fuel pump which all (only American-sold models as far as we know) BMWs equipped with the 3.0-litre twin-turbo straight six engine are fitted with. This fuel pump is said to be prone to failing. Once the pump does fail the car is said to go into 'Limp Mode' to prevent internal engine damage.
A lawsuit filed by Kershaw, Cutter and Ratinoff, LLC of California, claims that if the pump fails under certain circumstances, it might present a degree of danger. The law firm also claims BMW purposely withheld information on the potential failure problems from consumers and from the National Highway Traffic Safety Administration.
BMW has since announced it will extend emissions warranty to ten years on all potentially affected BMW N54-fitted models. The model years range from 2007 to 2010. No reports of the problem have surfaced in Australia as far as we know.
The lawsuit could push BMW into announcing a recall on the models though. We'll keep you posted.
Autoblog have contacted BMW US on the matter. The company couldn't comment on the lawsuit but provided the following statement:
"BMW has discovered that certain 2007-2010 model year vehicles may experience partial failure of the High-Pressure Fuel Pump (HPFP) which is part of the direct fuel injection system on certain 1 Series, 3 Series, 5 Series, X6, and Z4 models. Specifically, vehicles powered by the twin-turbocharged 3.0-liter inline-6 engine (internally dubbed "N54") are affected. Symptoms include long engine starting times and sometimes the illumination of the Service Engine Soon lamp in the instrument cluster, possibly accompanied by reduced engine performance (Fail Safe operation).
"As a result, BMW will extend the emissions warranty coverage period to 10 years or 120,000 miles, whichever comes first, on affected vehicles in all 50 States. If the HPFP fails during the extended warranty coverage period, BMW will replace it with a newer-production version.
"Customers who experience long starting times or notice the Service Engine Soon lamp should contact an Authorized BMW Center to schedule a service appointment. Customers with further questions should contact BMW Customer Relations."