BMW 730d

EGR cooler can fail and allow coolant into the intake tract. Documented cases of engine damage shortly after EGR cooler replacement.

Symptoms: Coolant loss, white smoke, engine check light, overheating

Early B57 models (from about 2015/16) show chain elongation with rattling noises on startup. Timing chain replacement requires engine removal. Repair costs comparable to the N57. Significantly rarer from 2018 models.

Symptoms: Metallic rattling on cold start, especially at low temperatures; subsides after warm-up; in extreme cases engine stumble

Bearing damage occurs in the bi-turbo system at higher mileage. Turbine blades can break off and cause engine damage. Frequently encouraged by insufficient oil change intervals.

Symptoms: Whistling or howling under load; blue exhaust smoke; power loss; MIL; in extreme cases sudden power loss from turbo failure

The EGR valve cokes up with frequent short-trip driving and becomes stiff. Stumbling on cold start is characteristic. BMW carried out a voluntary service action.

Symptoms: Stumbling and hesitation on cold start until the engine warms up; power loss; 'Drivetrain malfunction' message; black smoke; EGR valve fault

NOx sensors and SCR dosing unit fail after about 100,000 km or through AdBlue crystallisation. Fault code 26F500 is typical. BMW repairs often cost 2,000–4,000 EUR as entire systems are replaced.

Symptoms: MIL with message 'AdBlue system faulty' or 'Emission system fault'; fault code 26F500; engine runs normally but warning persists

Wiring harness problems or CAN bus faults cause fault messages across many control units simultaneously.

The PHEV system has no alternator. A fault in the SME module opens the contactors and the 12V battery discharges while driving.

Air bellows become porous from around 100,000–150,000 km; the compressor overheats from frequent pumping and fails. Car sags on one side or completely.

Signal fault in the motor position sensor can deactivate hydraulic brake assist. Approximately 1 million vehicles worldwide.

Recall KBA 16187R: a potentially misrouted cockpit wiring harness can be damaged during cabin filter replacement. A short circuit can cause smoke or fire — 337,374 vehicles worldwide affected.

G11 sags unevenly at all four wheels overnight. No fault code stored.

NOx sensor upstream of the SCR catalyst fails. Complete tank replacement costs 2,500–3,000 €.

Blocked or porous panoramic roof drain tubes channel water into the cabin instead of outside. Water collects in the headlining and runs toward the battery or control units.

Driver assistance systems on the G11 (lane keep assist, blind spot warning, junction assistant) malfunction frequently and require software updates or camera reinitialisations.

Faulty comfort access system draws continuously elevated current and drains the battery.

The interior door opening button integrated into the diamond light strip fails and no longer illuminates. Climate controls on the same side can also fail simultaneously. BMW replaces the entire light strip — approximately 4 weeks lead time.