BMW M340i Problems: 5 Issues Every Owner Should Know
2020-2024 model years · 1,250+ owner reports · Updated April 2026
According to Au7o's analysis of 1,250+ owner reports, the 2020-2024 BMW M340i has 5 documented known issues, with 2 rated critical. The most serious are Coolant Loss from Expansion Tank and Water Pump ($400-$1,200 repair) and High-Pressure Fuel Pump (HPFP) Failure ($600-$1,500 repair). The most commonly reported issue is Coolant Loss from Expansion Tank and Water Pump with 380 owner reports. Across all issues, repair costs range from $50 to $2,000. DIY maintenance guides at au7o.io.