BMW 220i G42

The B48 engine uses a polycarbonate oil filter housing that is prone to warping under repeated thermal cycling. When the housing or its gaskets fail, coolant can leak externally or, in worse cases, mix with engine oil. BMW is currently facing a class action lawsuit in the US over this exact defect affecting B46, B48, and B58 engines. Symptoms include a slow drop in coolant level with no visible external leak, or white/blue crystalline residue under the intake manifold. Repair at an independent shop typically costs around €1,200-1,500, while BMW dealer quotes can reach €2,000-2,500. An aluminium replacement housing is available as a permanent fix for a modest premium. The issue typically appears between 80,000 and 130,000 km, though some cases have been reported earlier.

The factory plastic coolant ventilation line running from the cylinder head to the expansion tank is exposed to high turbo heat and can become brittle over time. When it fails, it causes sudden coolant loss which can lead to rapid overheating if not noticed immediately. BMW issued a Technical Service Bulletin (TSB) in 2022 for this issue on earlier B48 applications and has been replacing the line with an improved rubber version under a service action in some markets. The part itself is inexpensive but diagnosis can be tricky if the leak is slow. At an independent shop, expect €200-400 for parts and labour; BMW dealers may charge up to €600.

Like all direct-injection engines without supplementary port injection, the B48 accumulates carbon deposits on the back of the intake valves over time. Fuel detergents cannot reach these surfaces because fuel is sprayed directly into the combustion chamber. Symptoms include rough idle, slight hesitation on acceleration, and marginally increased fuel consumption. The recommended remedy is walnut blasting every 60,000-100,000 km, which costs €400-600 at a specialist or €600-800 at a BMW dealer. While not a sudden failure, neglecting this service can lead to misfires and reduced engine efficiency over time. Using quality fuel and regular oil changes can slow the buildup.

The B48 valve cover integrates the PCV (positive crankcase ventilation) system, which includes a rubber diaphragm that can crack under pressure cycling. When the diaphragm fails, it causes pressure imbalances that accelerate oil leaks past the valve cover gasket. Symptoms include a burning oil smell, visible oil on the engine, and in some cases oil contaminating spark plug wells. The valve cover gasket itself is inexpensive but BMW often requires the entire valve cover assembly to be replaced (approximately €400-500 for the part alone), pushing total repair costs to €600-1,200 including labour. This typically occurs between 100,000 and 160,000 km.

BMW issued a global recall in February 2026 affecting 575,000 vehicles including the G42 2 Series Coupe. The starter motor solenoid switch can experience increased wear from repeated start cycles, potentially causing an internal short circuit that leads to overheating or, in rare cases, fire. Affected starter relays were produced between July 2020 and July 2022. The repair is free of charge at any BMW dealer and involves replacing the starter motor (approximately 2 hours of work). NHTSA has advised affected owners to park outside and away from structures until the repair is completed. Always verify with VIN whether this recall has been completed before purchasing.

Early G42 models equipped with iDrive 8 have been reported to experience intermittent screen freezes, Bluetooth device memory loss, and Apple CarPlay disconnections. A TSB exists for the G42 noting that the central display may flicker and paired Bluetooth devices can be deleted after the vehicle has been off. Most issues are resolved through over-the-air software updates or a dealer software flash. A soft reset (holding the volume knob for 30-70 seconds) often resolves temporary freezes. While annoying, these are not mechanically significant and BMW has been steadily improving the software through updates.