EngineCreep
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BMW B48
in every car

2 cars · scores 79–82/100

We score the B48 in 2 cars. The best is the 120i F20 LCI at 82/100, the weakest the 320i F30 at 79/100.

What the B48 is known for

The B48's weak spot is its cooling system, not its internals. The oil filter housing, a plastic part under the intake manifold, can crack or lose its gasket and leak coolant or oil. Because the manifold has to come off to reach it, the repair costs more than the part suggests: €700–1,800 on our owner reports, typically from around 80,000 km. BMW has since revised the housing.

The electric water pump is the other regular failure, from around 110,000–115,000 km on our data, at €300–900. It is cheaper, but it can leave you stranded when it goes. Check the coolant level with the engine cold, look for dried coolant traces around the back of the engine, and ask whether the pump has been replaced.

Version by version

  1. BMW B48 in the 120i F20 LCI2016–2019

    82/100Good

    13 confirmed issues

    Best-known problemWater pump failure · from 112k km · €300–900

  2. BMW B48 in the 320i F302015–2018

    79/100Good

    12 confirmed issues

    Best-known problemOil filter housing coolant leak · from 80k km · €700–1,800

The problems they share

Reported on all 2

  • Water pump failure
  • Timing chain stretch / guide wear
  • Piston ringland failure
  • Thermostat / temperature sensor failure
  • High-pressure fuel pump failure
  • Oil leak from seals or gaskets
  • Fuel injector failure
  • Excessive oil consumption
  • Variable valve timing solenoid/actuator failure
  • Intercooler failure or leak

Only reported on the 120i F20 LCI

  • Head gasket failure
  • Wastegate / boost actuator failure
  • ECU fault or wiring issue

Only reported on the 320i F30

  • Oil filter housing coolant leak
  • Oil pump wear / sludge buildup

A problem missing from a version may be rarer there, or have fewer owner reports behind it so far.

Before and after

It replaced the BMW N20, which scores 45–52/100 across 3 cars.