2010 BMW 6 Series Problems: 10 Known Issues

On the 2006-2010 BMW 6 Series S85B50, the S85 V10 in the 2006-2010 M6 shares the E60 M5's rod bearing issue: tight bearing clearances combined with the factory 10W-60 oil produce accelerated wear, and worn bearings can progress to a spun bearing and engine destruction. M5Board's picture thread and M6-specific threads show bearings pulled between roughly 60,000 and 100,000+ miles with copper showing through; cold-start knocking and metal in the oil are the late-stage signs. BMW's own position was that high-RPM use accelerates wear. This applies only to the S85 M6, not the N62 645Ci/650i.

On the 2004-2010 BMW 6 Series N62, the N62 4.4L/4.8L V8 engine in E63/E64 645Ci and 650i (2004-2010) develops hardened valve stem seals that allow oil to leak past the valve guides into the combustion chambers. This causes heavy blue smoke on cold startup (most noticeable after overnight sitting), excessive oil consumption (1+ quart per 1,000 miles), and fouled spark plugs. The valve stem seals harden and crack from heat cycling over time, typically becoming problematic around 80,000-120,000 miles. Traditional repair requires cylinder head removal ($8,000-12,000 at dealer), but the AGA Tools N62 valve stem seal tool kit (about $1,300 new) enables in-car repair without removing the heads, dramatically reducing labor costs. Elring seals 11340029751 ($78 for all 32 seals) are high quality and widely available through FCP Euro.

On the 2004-2010 BMW 6 Series, on the N62 V8 (N62B44 in the 2004-2005 645Ci, N62B48 in the 2006-2010 650i) the alternator mounts on a cast bracket that doubles as an oil passage cover; its rubber gasket hardens and leaks. Owners on Bimmerfest and BimmerForums UK report oil coating the alternator, sway bar bushings and the front subframe, with heavy leaks losing a noticeable amount of oil between changes. It is one of the most common N62 leak points along with the valve cover gaskets and the upper timing cover gaskets, and is distinct from the valve stem seal and coolant pipe issues already documented.

On the 2004-2010 BMW 6 Series, the SMG (Sequential Manual Gearbox) hydraulic system in E63 M6 (2006-2010, 7-speed SMG III) and SMG-equipped E63/E64 645Ci/650i (2004-2010, 6-speed SMG) suffers from hydraulic pump motor failure. A failed or failing pump MOTOR (carbon brush dust contamination) is one of the biggest causes of SMG pump failure, NOT necessarily the pump itself - but shops commonly misdiagnose and replace the entire pump assembly at $5,000-6,500 OEM cost. The pump motor brushes wear down over time, creating carbon dust that contaminates the motor internals. Motor-only replacement ($200-350) often resolves the fault and does NOT require hydraulic bleeding. Full pump replacement requires hydraulic system bleeding and is significantly more expensive.

On the 2004-2010 BMW 6 Series, nHTSA campaign 10V-446 (October 2010) covers 2004-2010 6 Series with the N62 V8 (645Ci, 650i; the S85-powered M6 is not included) along with 2004-2010 5 Series and 2002-2008 7 Series, about 198,000 vehicles. The check valve on the engine-driven brake vacuum pump can pass a small amount of lubricating oil into the vacuum line, which over time contaminates the brake booster and degrades or, in extreme cases, eliminates power brake assist. Bimmerfest threads report that on some cars the recall fix did not restore assist because the pump or booster were already oil-contaminated, and that the vacuum pump itself was not covered.

On the 2004-2010 BMW 6 Series, nHTSA campaign 12V-126 (March 2012) covers 2004-2010 6 Series and 5 Series. The insulated bulkhead connector that passes the positive battery cable through the trunk floor may have been incorrectly attached at the factory; the bolted joint can loosen, resistance rises and the connection overheats, with a fire risk even when the car is parked. BMW advised owners to park outside until repaired. On the E63/E64 the battery and this connector are in the trunk.

On the 2004-2010 BMW 6 Series, the E64 convertible has drains in the top storage well that route through rubber hoses over the trunk-side electronics. Leaves and debris collect at a T-fitting, the drains back up and water runs into the trunk, where the Logic7 amplifier, satellite receiver, fuse block and battery live. Bimmerfest and M5Board threads document soaked trunk carpet followed by loss of audio, 'central electronics failure' messages and other trunk-module faults on 645Ci/650i/M6 convertibles. Owners note BMW addressed the drain routing under a campaign but did not cover the amplifiers it had already damaged. This is separate from the hydraulic top mechanism failure already documented.

On the 2004-2018 BMW 6 Series, e64 (2004-2010) and F12 (2012-2018) convertible models experience hydraulic top mechanism failures due to pump motor corrosion, seal degradation, and hydraulic cylinder leaks. The convertible top may stop mid-cycle, operate slowly, or refuse to open/close entirely. The hydraulic pump motor is prone to corrosion from moisture intrusion, and the hydraulic cylinders develop seal leaks over time. OEM pump replacement is extremely expensive ($2,000-3,500 for E64 pump 54347154648, similar for F12 pump 54347299838). Top Hydraulics (tophydraulics.com) offers pump and cylinder rebuild services ($600-1,200 with 3-year warranty) that are universally recommended by the E64/F12 community as superior to new OEM parts. Their rebuilt pumps and cylinders often outlast new OEM units.

On the 2006-2010 BMW 6 Series S85B50, the S85 uses separate throttle actuation for each bank. Actuation faults can cause reduced power, but the fault code and live position data identify a diagnostic path rather than uniquely proving worn gears. Mechanical, motor, electronic, supply and connection faults must be distinguished.

On the 2004-2010 BMW 6 Series, e63/E64 cars optioned with Dynamic Drive use hydraulic active anti-roll bars fed by the power steering pump. Owners report 'Dynamic Drive failure' / 'Active Roll Stabilization malfunction' warnings, often intermittent, with codes 5D5B (pressure build-up front axle) or 5D5C (pressure sensor rear axle) stored in the ARS module. Root causes documented on Bimmerfest include low or degraded shared hydraulic fluid, leaking hydraulic lines or actuator seals, failing pressure sensors, a weak battery or over-voltage from a failing alternator regulator, and a lost calibration after battery disconnect. Because Active Steering shares the same hydraulic supply, the two warnings frequently appear together.