According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2018 Buick Envision has 9 documented known issues, with 4 rated critical. The most serious are Fuel Dilution of Engine Oil from Stuck PCV Valve (2.0T LTG / 2.5L LCV) ($180-$650 repair), Brake Vacuum Pump / Booster Pressure Sensor Failure Triggering 'Service Brake Assist' and Hard Pedal ($300-$950 repair), Front Brake Hose Rupture Causing Sudden Pedal-to-Floor Brake Loss ($250-$900 repair) and Sudden Loss of Electric Power Steering Assist with DTC C056E-5A ($200-$1,500 repair). Across all issues with published estimates, repair costs range from $150 to $1,600. DIY maintenance guides at au7o.io.