BMW 1er F70

Modular four-cylinder turbo and workhorse of the current BMW lineup. Wide power range from 135 to 306 hp (M135i/M235i). Structurally the best four-cylinder petrol BMW has ever built: timing chain at front, closed oil circuit, Valvetronic variable valve lift. Oil consumption stays under control when BMW-spec oil (LL-01 or LL-17FE+) is used. Typical wear items are the electric water pump (from around 80,000 km) and the high-pressure pump with direct injection. Not an engine to fear — but BMW service intervals are too long; those who care for their B48 change oil every 10,000-12,000 km.

• !! Timing chain guide rail breaks from 60,000 km

  Timing chain guide rail can break; chain jump and engine damage follows. More common on early production years and with spirited driving.

  Symptoms: Rattling, clattering from the engine, sudden power loss, engine damage
  2,000–4,000 $
  Ad BMW B48 timing chainBMW B48 GleitschieneBMW B48 chain tensioner
• !! Oil filter housing leaking — coolant loss from 60,000 km

  Oil filter housing with integrated oil/water heat exchanger leaks. Coolant loss and overheating risk from about 60,000 km.

  Symptoms: Coolant level warning, oil puddle under engine, overheating
  400–1,200 $
  Ad BMW B48 oil filter housingBMW B48 heat exchanger11428643747
• !! Coolant bleed line at cylinder head breaks from 70,000 km

  A plastic bleed line between the cylinder head and expansion tank becomes porous and breaks. Coolant loss follows; the mounting location is difficult to access, so labour costs dominate.

  Symptoms: Dropping coolant level; coolant warning on the instrument cluster; faint sweet smell; no visible puddle under the car
  300–700 $
  Ad BMW B48 coolantleitung cylinder headBMW B48 breather line

+ 6 more engine weaknesses + vehicle weaknesses