2021 BMW 4 Series problems

“The engine starter motor system failed, specifically involving an intermittent no-start condition related to a pinion starter line break / internal component defect. The vehicle and all original mechanical components are fully intact and available for professional inspection upon request. The engine starter motor system failed, specifically involving an intermittent no-start condition related to a pinion starter line break / internal component defect. The vehicle and all original mechanical components are fully intact and available for professional inspection upon request. The vehicle is currently experiencing these active symptoms. The vehicle experiences sudden, unpredictable intermittent no-start scenarios. Being unable to dependably start or restart the engine creates a severe risk of stranded occupants in hazardous traffic scenarios, remote areas, or extreme weather conditions. Furthermore, this failure pattern matches identical 2026 BMW starter recalls where internal mechanical wear creates a severe overheating condition and an elevated vehicle fire risk, directly threatening passenger safety. No, the component has not yet been formally inspected by the…”

“The recall was issued more than 8 months ago but the remedy is still not yet available, which is very concerning as the problem may cause the event of fire even when the vehicle is parked. Issued SEP 23, 2025 Description of Problem It is possible for water to contact and enter the engine starter. This could lead to corrosion which could cause a short circuit. Safety Risk This could increase the risk of a thermal event or fire during driving or even when the vehicle is parked and the ignition is off.”

“I am seeing a lot of concerns regarding the seatbelt extenders, the buckle end pretensioner, seat wiring harness and the yellow box connectors that are where the main power and air bag SRS connections sit under the drivers seat. The seat harnesses are catching in the sliding track mechanism during forward and backward adjustments, isn't that a manufacturer error as the harnesses are only kept in place by plastic routing clips, which may or may not be there. I am just wondering if this should be looked at on the 2021 440i convertibles? I love the car but worry this is a safety issue forums are mentioning. Car alarms 1m-4am is that software updates, went on for four days in June.”

“BMW dealer noted "clunk on accel" at 57,152 miles on RO #224018 under engine mounts. Dealer quoted $3,463.38 for engine mounts. I declined repair. Clunk on acceleration is still present at 60,700 miles. Same symptom as BMW Service Bulletin SIB 27-02-20 for 4 Series Drive jerking/shuddering from transfer case. Transfer case was serviced by non-BMW shop prior to my ownership (unknown fluid spec). Dealer documentation only notes clunk on accel and engine mounts/alignment. Requesting investigation as this matches known transfer case defect with lifetime fluid claim. Vehicle is just out of 4yr/50k warranty.”