BMW M5 F90

The coolant expansion tank sits between the two turbochargers in the engine V. Heat degrades the plastic, causing it to crack at a seam. Leaked coolant drips directly onto cylinders 5-8 fuel injectors and ignition coils. If caught early, the tank replacement costs around €150-300 in parts plus labor. If coolant has contaminated injectors, replacing 4 injectors adds €1,500-3,000. BMW issued a TSB (17 02 22) and later a recall for 2018-2023 models produced between November 2017 and September 2022. Verify with VIN whether the revised tank (part 17137889450) has been fitted. Failures have been documented at as early as 5,000 km and as late as 60,000 km. The LCI models (2021+) shipped with the revised tank.

Primarily affects early 2018 production models. BMW recalled approximately 850 vehicles where the engine control unit software could cause the fuel pump to stop functioning during certain driving conditions. Symptoms include engine dying on startup or stalling. A separate recall (19V-513) addressed high-pressure fuel pump flanges that were not properly attached, causing potential fuel leaks on 2019-2020 models. Both recalls involve free dealer repairs. If purchasing used, verify completion with VIN. If the recall was not performed and the pump has failed out of warranty, replacement costs €800-1,500.

The M xDrive system uses a transfer case with clutch packs that can wear over time, particularly in cars driven aggressively or on track. Symptoms include shuddering or binding sensation during tight turns at low speed, similar to 4WD binding. The actuator motor is often the first component to fail and can be replaced separately for €1,000-2,000. If the internal clutch packs are worn, full transfer case replacement runs €3,500-5,000. Regular fluid changes at 100,000 km help prevent this. Most reported cases appear beyond 80,000 km.

The S63 engine uses four VANOS solenoids that can develop deposits over time, particularly with extended oil change intervals. Symptoms include rough idle, hesitation, power loss, and fault codes. Individual solenoid replacement costs €100-200 per unit. Replacing all four with labor typically costs €400-800. If left unaddressed, incorrect valve timing can cause secondary damage. Generally appears around or beyond 100,000 km. Using high-quality oil and maintaining strict 10,000 km or annual oil change intervals significantly reduces risk.

The twin turbochargers on the S63TU4 are generally robust, but wastegate actuator bushings can wear over time, causing a rattle on cold start or deceleration. In most cases this is cosmetic and does not affect performance. If wastegate wear progresses to cause boost leaks or fault codes, turbo replacement is required. Single turbo replacement costs €3,000-4,000 including labor. Full twin-turbo replacement at a dealer can reach €6,000-8,000. This is rare on stock engines under 150,000 km. Heavily tuned cars are at much higher risk.

Multiple F90 owners report a clunking noise from the front suspension during low-speed maneuvers or over bumps. BMW dealers have identified two causes: improperly torqued subframe stiffener plate bolts (free fix under warranty, cheap if out of warranty) and worn thrust arm bushings (common BMW wear item). Bushing replacement costs €300-600 per side. If the noise persists without repair, it can lead to uneven tire wear. Most reports occur between 40,000-80,000 km. The LCI model's revised adaptive suspension has somewhat reduced reports.

BMW considers up to 1L per 1,500 km acceptable for M engines under hard use. However, if consumption exceeds this or blue smoke is visible on startup, valve stem seals are likely worn. Due to the hot-vee turbo configuration generating extreme heat, seals degrade faster than in naturally aspirated engines. Repair requires removing VANOS units and camshafts, costing €2,500-5,000 depending on shop. Most F90 M5s at normal mileage (under 100,000 km) show acceptable consumption with proper oil choice. Strict adherence to 10,000 km oil change intervals helps longevity.