"Is the 6 Serisi 635d reliable, and what should you check?"
When buying a used BMW 6 Series 635d 2009 (E63 / E64 / facelift), the most frequently mentioned issue is: Carbon buildup / Clogged EGR. Also, oil leaks and worn gaskets are commonly reported.
Engine: M57
M57D30 · turbo petrol · 635d · Used in this car from 2007-2010
Known engine issues
Swirl flapsThe first generation of this diesel was equipped with steel intake swirl flaps that could break off and fall into the cylinders, usually fatal for the engine. After modernization, plastic flaps appeared and they are relatively safe.
Fuel systemThe Bosch Common Rail system with electromagnetic injectors is very reliable and has a huge service life; it is important not to skimp on fuel quality and maintenance. At high mileage, leaks at the rail pressure regulator and failure of the high-pressure pump (sometimes just replacing its filter) occur periodically.
TurbochargerThe turbocharger itself is quite durable and rarely causes trouble; boost problems are usually related to cracks in vacuum hoses or a stuck pressure regulator. Note that the turbo can also leak oil if the crankcase ventilation is faulty.
+2 more issues on the engine detail page
Known issues and risks
Listed from most frequently reported, each with its source.
Carbon buildup / Clogged EGR
Often reported
The M57 twin-turbo 3.0 engine (286 HP), especially with city driving or after remapping, is prone to heavy carbon deposits in the EGR, intake ports, and manifold; this can cause idle fluctuations, cold start issues, and power loss.
Engine Internal
Oil leaks and worn gaskets
Often reported
As M57 engines in E60/E63 vehicles age, oil leaks from sealing points (valve covers, manifold gaskets, hoses, and various connections) are frequently reported. Gasket deterioration can lead to abnormal oil consumption and maintenance interventions.
Engine Internal
Faulty intake flaps/swirl flaps
Often reported
The intake flaps in the M57 engine can become dirty or break with increasing mileage; in severe cases, broken parts can fall into the cylinders, posing a risk of major engine damage.
Engine Internal
Turbo wear or failure
Often reported
In BMW M57 diesel engines, especially high-mileage or poorly maintained vehicles, the turbocharger or its actuators can wear out, causing power loss, delayed response, and unusual noises.
Turbo
BMW 6 Serisi 635d technical specs
BMW 6 Serisi 635d (2009): boot 450 L; fuel use 6,9 l/100 km (urban 9,2 l/100 km · extra-urban 5,6 l/100 km); 0–100 in 6.3 s.
Boot capacity
450 L
Fuel consumption
6,9 l/100 km (urban 9,2 l/100 km · extra-urban 5,6 l/100 km)
What to look for when buying a BMW 6 Series 635d?+
When buying a 2009 635d, check service history, test drive, and look for engine/transmission warnings. Most commonly reported issues: Carbon buildup / Clogged EGR; Oil leaks and worn gaskets; Faulty intake flaps/swirl flaps.
What are the chronic problems of the BMW 6 Series 635d?+
Most commonly reported issues: Carbon buildup / Clogged EGR; Oil leaks and worn gaskets; Faulty intake flaps/swirl flaps.
Is the BMW 6 Series 635d reliable?+
Rather than a simple yes/no, it is necessary to evaluate proven pros and cons together. This page lists 4 verified findings.
How does Carbeak collect data?+
The cards on this page are derived from Difetti fault database records; compatibility of brand, fuel, engine, and generation between source and target vehicle is verified. Topics with insufficient evidence are not shown.