BMW 750i G11

The hot-V layout places the twin turbochargers between the cylinder banks, where temperatures are extremely high. The turbo coolant lines contain rubber sections that harden and crack over time, leading to coolant leaks. This is one of the most commonly reported issues on the G11 750i, particularly on pre-LCI models (2015-2019 with N63TU2). Symptoms include low coolant warnings, visible coolant residue in the engine valley, and in severe cases overheating. BMW issued a service action for turbo coolant lines on N63-equipped models, but the problem can recur even after the campaign repair. Dealer repair typically costs €3,000-3,500 due to extensive labor required to access the lines between the cylinder banks. Independent specialists can often replace just the degraded rubber sections for €1,500-2,000. Aftermarket repair hose kits are available for under €100, but professional installation is still recommended due to the tight packaging. LCI models (2019+) with the N63TU3 have improved thermal management but are not immune.

The N63 engine family has a well-documented history of valve stem seal degradation. The hot-V design exposes the seals to elevated temperatures, causing the rubber to harden and lose its sealing ability over time. Symptoms include a visible puff of blue smoke from the exhaust on cold start and increasing oil consumption, sometimes exceeding 1 litre per 1,000 km. BMW considers up to 1 quart per 1,200 km as within specification, though many owners find this excessive. The N63TU2 (pre-LCI) is more susceptible than the N63TU3 (LCI), which received updated seal materials. Repair requires removing the valve covers and replacing all 32 seals. Specialist workshops in Western Europe charge approximately €3,000-4,000, while BMW dealers can quote €5,000-6,000. A class action settlement in the US covered N63TU engines but not the N63TU2 specifically. Upgraded aftermarket Viton seals are available and are more heat-resistant than the original specification.

The G11 7 Series has air suspension as standard on all models. The air spring bladders are made of 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 lifespan. OEM replacement front struts cost approximately €1,500-2,000 each from BMW. Aftermarket specialists like Aerosus and Miessler offer remanufactured units from €700-900 per strut. Rear air springs are somewhat cheaper at €500-800 per side. The compressor costs approximately €500-700 for the part. BMW has offered an extended warranty on air suspension struts for the G11/G12, covering vehicles under 8 years and 80,000 km. Issues typically appear after 80,000-120,000 km or 6-8 years. Cars driven regularly on poor road surfaces or in corrosive winter conditions fail earlier.

The twin turbochargers each have a wastegate actuator with an internal rubber diaphragm. Oil vapor from the hot-V crankcase ventilation system gradually causes this diaphragm to swell and fail. Symptoms include a rattling noise from the engine bay on startup or acceleration, reduced boost pressure, an EPC warning light, and limp mode. BMW has issued a service information bulletin (SIB 01 07 21) for wastegate actuator replacement. When caught early, the actuator alone can be replaced for approximately €500-800 at a specialist, with some repair services offering refurbishment of the original unit. However, if turbo internals are damaged, a full turbocharger replacement is needed, which runs €2,000-2,500 per side due to the labor-intensive access. On the G11, access to the turbos requires significant engine bay disassembly.

The valve cover gaskets on the N63 engine sit very close to the hot turbochargers in the V of the engine. The extreme heat accelerates gasket degradation compared to conventional engine layouts. Oil typically begins to weep along the gasket edges, eventually dripping onto hot exhaust manifolds and producing a burning oil smell. If ignored, the leak can worsen and cause smoke from the engine bay. The repair requires removing both valve covers — a straightforward but time-consuming job on the N63 due to the crowded engine bay. Parts cost approximately €150-250 for both gaskets and associated seals. Labor is the main expense: BMW dealers charge approximately €1,500-2,000 total, while independent BMW specialists typically charge €1,200-1,500. This issue commonly appears between 80,000-130,000 km.

The G11 7 Series has over 100 electronic control units, comfort access sensors, gesture control, and various telematics modules that maintain a constant current draw even when the car is parked. Many owners report the battery going flat within 5-10 days of not driving. This is particularly problematic for cars that are not driven daily. The AGM battery costs approximately €250-400 for replacement, and must be registered to the car via BMW diagnostic software to ensure the charging system operates correctly. A quality trickle charger (CTEK MXS 5.0 or similar) is practically a mandatory accessory. Software updates from BMW have improved sleep mode management on some cars, but the fundamental issue is the sheer number of systems that remain partially active. If the battery drains repeatedly, it can cause cascade errors in multiple electronic modules, leading to expensive diagnostic sessions.

The G11 was BMW's most electronically complex car when launched, featuring gesture control, a touchscreen iDrive, optional remote parking, and extensive driver assistance systems. Owners report occasional iDrive freezes, unexpected reboots, gesture control misinterpreting hand movements, and random pop-up warnings on the dashboard. Most software-related issues can be resolved with firmware updates at a BMW dealer, typically at no charge if under warranty or a nominal diagnostic fee otherwise. Hardware failures — such as a defective iDrive head unit or a failing radar sensor — are more expensive, ranging from €500 to €2,000 depending on the component. Keeping the car on the latest software version significantly reduces the frequency of electronic glitches.