2025 vs 2026 BMW 4 Series

Both years

• Thermostat and coolant pump on the 430i All years One source so far

  What to check: Watch the temperature gauge on a long drive for overheating warnings or a wandering needle, and ask whether the thermostat or auxiliary coolant pump has been replaced.

  Euro Premium Parts calls the electronic thermostat and auxiliary coolant pump weak points, usually failing between 40,000 and 70,000 miles, and lists oil use and the odd high-pressure fuel pump failure on the same engine.

  A seller's guide (unofficial)

• Oil filter housing seep on the M440i All years One source so far

  What to check: Look for oil around the oil filter housing.

  Euro Premium Parts says its gasket is prone to seeping at around 60,000 to 90,000 miles, a cheap part that takes labor to reach.

  A seller's guide (unofficial)

• Electric water pump on the M440i All years One source so far

  What to check: Ask whether the electric water pump has been replaced on a car near 80,000 miles, and look for a coolant warning.

  Euro Premium Parts says the B58's electric water pump has a known failure pattern and advises replacing it before 80,000 to 100,000 miles.

  A seller's guide (unofficial)

• The mild hybrid's starter-generator All years

  What to check: Ask for proof that every starter-generator and starter recall has been done, and scan for stored fault codes.

  Euro Premium Parts reports fault codes and failures of the belt starter-generator and its wiring on early cars. NHTSA lists recalls for its battery connection on 2021 M440i xDrive coupes and 2025 430i cars.

  NHTSA, a seller's guide (unofficial)

• Worn front control arm bushings All years One source so far

  What to check: On the test drive, feel for the car following ruts in the road or vague steering.

  Euro Premium Parts says the front lower control arm bushings wear between 40,000 and 60,000 miles, especially on xDrive cars.

  A seller's guide (unofficial)

• Early iDrive 7 glitches All years One source so far

  What to check: Try the screen, Bluetooth, reversing camera and parking sensors, and ask whether the software is up to date.

  Euro Premium Parts says early cars' screens could freeze or drop Bluetooth, mostly cured by over-the-air updates, and reports camera and parking sensor faults from damp.

  A seller's guide (unofficial)

Both years

Engines

2.0L turbo four-cylinder Edmunds, a published reference, 3.0L turbo inline-six with a 48-volt mild hybrid Edmunds, a published reference

Transmissions

Eight-speed automatic Edmunds, a published reference

Drivetrains

Rear-wheel drive Edmunds, a published reference, xDrive all-wheel drive Edmunds, a published reference

Body styles

Coupe Edmunds, a published reference, Convertible Edmunds, a published reference, Gran Coupe (2022–2026) NHTSA, a published reference

Packages

M Sport Package CarGurus, Edmunds, Premium Package Edmunds, Convenience Package Edmunds, Executive Package Edmunds, CarGurus, Dynamic Handling Package Edmunds, Parking Assistance Package Edmunds, Driving Assistance Package Edmunds, Driving Assistance Professional Package Edmunds, CarGurus, Shadowline Package Edmunds, Cooling and High Performance Tire Package CarGurus

Both years

• Sought after: The six-cylinder M440i All years One source so far

  Euro Premium Parts calls the M440i the sweet spot for most buyers, with near-M performance from a six it rates for long life. A seller's guide (unofficial)