BMW xDrive40d

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

Air springs and compressor are the most common failure points on the G07. Porous air springs put continuous load on the compressor until it fails too. Total costs up to €7,000.

A signal fault in the motor position sensor of the integrated braking system can cause the hydraulic brake assistance and ABS/DSC regulation to fail.

A defectively manufactured starter motor can overheat after repeated start attempts and ignite insulating material in the engine bay. Affects model years 2019–2020.

Vehicles with optional active steering can display a fault message. The steering wheel can rotate up to 60 degrees at standstill. Repair is often lengthy; costs up to €4,000.

The drainage hoses for the large panoramic roof block with leaves and dirt. If water backs up, it enters the cabin. Cleaning is part of maintenance but is often forgotten.