BMW 740d G70

The G70 7 Series has air suspension as standard. The air spring bladders are reinforced rubber that deteriorates over time due to road salt, UV exposure, and thermal cycling. When a bladder leaks, the affected corner sags, typically noticed after the car sits overnight. The compressor then runs excessively to compensate, shortening its own lifespan. OEM front struts cost approximately €1,500-2,000 per corner from BMW. Aftermarket options from Arnott or similar suppliers run €700-1,000 per strut. Rear air springs are somewhat less expensive at €500-800 per side. The compressor itself costs €500-800 for the part. Issues typically emerge after 80,000-120,000 km or 5-7 years. Vehicles driven regularly on poor roads or in areas with heavy winter salting fail earlier. Always inspect all corners at equal height after the car has sat overnight.

BMW recalled the G70 7 Series (and G60 5 Series) for a defect in the Continental-supplied integrated braking system. The welds in the servomotor hollow shaft may break, causing loss of power brake assist and potentially disabling ABS and DSC. The root cause was traced to contaminated circuit boards at a Continental plant in Hungary. BMW expanded the recall in late 2024, affecting approximately 1.5 million vehicles globally across 2023-2025 production. Some replacement modules initially installed under the first recall also failed to meet specifications, requiring a second replacement. Verify with BMW using the VIN that all IBS-related recalls have been completed, ideally twice if the car was built in 2023. Out-of-recall module replacement costs €1,000-3,000 at a BMW dealer.

The B57 diesel uses a selective catalytic reduction (SCR) system with AdBlue injection and NOx sensors upstream and downstream of the catalytic converter. The NOx sensors operate in extremely harsh conditions, exposed to vibration, heat, salt, and corrosive exhaust gases, and are known to fail on BMW diesels typically between 80,000-150,000 km. Symptoms include an engine management warning light, reduced performance, and in severe cases a mileage countdown warning that prevents the engine from starting if not addressed. A single NOx sensor costs €400-600 for the part, plus €200-400 in labor. If the SCR catalyst itself has degraded, costs can reach €1,500-2,000 for the assembly. Using genuine AdBlue from reputable suppliers and avoiding low-quality fluid helps extend sensor life.

The G70's massive curved display running iDrive 8 (and later 8.5) is reported by owners to freeze, randomly reboot, or go completely black while driving. GPS positioning can drift when smartphone projection (Apple CarPlay/Android Auto) is active. The interaction bar on the dashboard may also malfunction, failing to illuminate when pressed or not activating defogger/hazard lights (subject to a specific recall for early 2023 production). Most software-related issues can be resolved with a soft reset (hold volume knob for 30 seconds) or by having the dealer install the latest firmware. Hardware failures of the head unit itself are rare but cost €1,000-1,500 to replace. BMW has addressed many initial bugs through OTA updates, so cars running newer software versions are less affected.

The B57 engine has a significantly more durable DPF than earlier BMW diesel engines, but it still requires regular regeneration. The DPF regeneration process needs approximately 20-30 minutes of driving at highway speeds to complete. Cars used predominantly for short urban trips may not reach the temperatures needed to burn off accumulated soot. Symptoms include reduced power, increased fuel consumption, and eventually a dashboard warning. A forced regeneration at a workshop costs approximately €200-300. If the DPF is heavily clogged, professional cleaning costs €400-600. Full DPF replacement costs €2,500-3,500 at a BMW dealer. Using low-ash specification oil (as recommended by BMW) and taking periodic long motorway drives significantly reduces this risk.

The G70 740d uses a 48V mild hybrid system with an integrated starter-generator (ISG) built into the ZF 8-speed transmission. BMW issued a recall in 2025 for certain models where a supplier-related manufacturing defect caused loose connector fittings between the ISG and the wiring harness, potentially leading to intermittent power loss or engine stalls. While the recall primarily affects 2025 3/4/5 Series models, the same ISG technology is shared across the CLAR platform. If the ISG fails outside of recall coverage, replacement costs €1,200-2,500 including labor, as the unit is integrated into the transmission housing. Early detection through monitoring start-stop functionality and checking for related fault codes is recommended.

The G70 7 Series has extensive electronic systems including the theater screen, gesture control, 5G connectivity, comfort access, and multiple cameras that maintain a parasitic current draw even when parked. Many owners report the battery going flat within one to two weeks of not driving. The AGM battery costs approximately €300-500 for replacement, and must be registered to the vehicle via BMW diagnostic software for the charging system to function correctly. A quality trickle charger (CTEK MXS 5.0 or similar) is strongly recommended for any car not driven daily. If the battery drains repeatedly, it can trigger cascade faults in multiple electronic modules, potentially requiring expensive diagnostic sessions to clear.