BMW 730d

As mileage increases the timing chain stretches and the chain tensioner loses its spring force. Broken plastic guide rails send fragments into the oil sump, which can damage the oil pump.

Symptoms: Rattling or clattering on cold start that improves once warm. Further wear can lead to engine damage.

The swirl flaps in the M57TUD30 intake manifold become heavy from carbon and EGR soot deposits and can break off. Metal fragments enter the combustion chamber and destroy valves and pistons.

Symptoms: Sudden hard engine knock, power loss, blue smoke, engine will not restart.

On the M57TUD30 (build dates July 2012–June 2015), coolant can escape from the EGR cooler and ignite with soot deposits. BMW recalled approximately 300,000 vehicles across Europe.

Symptoms: Engine warning light, power loss, in rare cases smoke from the engine bay or vehicle fire.

The M57TUD30 biturbo retains the familiar swirl flap problems of the M57. Even the reinforced versions after 2004 can develop leaks or stick.

Symptoms: Hesitation under acceleration, intake tract noise, power loss at part throttle, swirl flap actuator fault code

Diesel injectors wear at high mileage. Diagnosis via cylinder balance test and return flow measurement. Individual injector replacement possible at around €450 including installation.

Symptoms: Rough running especially at idle, hesitation, increased fuel consumption, white or black smoke.

The M57TUD30 biturbo shows oil loss through the turbocharger shaft seals at high mileage. Oil accumulates in the charge air hose and intercooler.

Symptoms: Oil film in the charge air hoses and at the intercooler outlet, blue smoke at full load, increased oil consumption without visible external leaks

The M57TUD30 DPF clogs particularly with frequent short-trip driving, as regeneration cycles cannot complete.

Symptoms: DPF engine warning light, increased soot output, power loss especially on motorway runs

The electronic steering column lock can seize and prevent the car from starting. BMW charged around 1,800 € for repair. One of the most expensive electrical problems of this generation.

The E65 is considered an electrical nightmare: comfort access, ISOFIX, various control units, and body electronics can fail. Even minor repairs easily cost over 1,000 €.

The rear air suspension on the E65 is a frequent and expensive weak point. Air bellows and compressor typically fail from 100,000 km. The car sags at the rear, especially after standing.

Blocked panoramic roof drains let water through the C-pillar into the boot. Up to 7 control units are located there.

Hydraulic power steering pump fails. Faulty vane pump or leaking pressure hoses as causes.

A weak battery causes apparent multiple faults: Dynamic Drive, DSC, gearbox, and steering show simultaneous errors.

Plastic water pipe on top of the N62 V8 engine becomes porous and leaks. Coolant loss can lead to overheating.

Solenoid valves in the air suspension compressor scale up from condensation. Compressor can often be repaired cost-effectively.