The 2022 Z4 (G29) with the B48 2.0L turbo four is essentially a Toyota Supra twin under the sheet metal. Despite being recent, we're already seeing catastrophic engine failures tied to oil starvation and bearing failures, especially in spirited driving conditions.
B48 Engine Bearing Failure and Oil Starvation
Occasional · high severityTypical onset: 15,000-50,000 mi
Symptoms: Rod knock or bottom-end rattling especially when cold, Metal shavings in oil filter during changes, Low oil pressure warning despite full oil level, Sudden catastrophic failure with no prior warning in some cases
Fix: Full short block replacement or engine rebuild required. BMW has issued technical service bulletins but warranty coverage is inconsistent. 25-35 hours labor for short block swap, more for full rebuild with machine work.
Estimated cost: $8,000-15,000
ZF 8HP Transmission Oil Cooler Leaks
Common · medium severityTypical onset: 30,000-60,000 mi
Symptoms: Transmission fluid spots under vehicle near front, Burnt transmission fluid smell after highway driving, Harsh shifting when cold that improves as fluid warms
Fix: Oil cooler assembly replacement, requires dropping transmission pan and sometimes removing transmission for access. 4-6 hours labor depending on whether trans needs to come out.
Estimated cost: $1,200-2,200
Starter Motor and Relay Failure (NHTSA Recall)
Occasional · high severitySymptoms: No-crank condition with dashboard lights functioning, Intermittent starting requiring multiple key cycles, Clicking from starter area with no engine turnover
Fix: Covered under recall for starter relay replacement. If outside recall scope, starter motor itself runs 3-4 hours labor due to tight engine bay access on the four-cylinder.
Estimated cost: $800-1,400
High-Pressure Fuel Pump (HPFP) Failure
Occasional · high severityTypical onset: 40,000-80,000 mi
Symptoms: Long crank times especially when hot, Misfires and rough idle under load, P0087 and P228C fuel pressure codes, Limp mode activation during acceleration
Fix: HPFP replacement requires removing intake manifold for access on B48 engine. Also recommend fuel filter change and injector inspection. 5-7 hours labor.
Estimated cost: $1,800-3,200
Power Window Regulator Failure (NHTSA Recall)
Occasional · low severitySymptoms: Window drops into door and won't raise, Grinding or clicking noise during window operation, Window operates slowly or unevenly
Fix: Window regulator replacement covered under recall. Outside recall, requires door panel removal and regulator swap. 2-3 hours labor per side.
Estimated cost: $600-900
Transmission Mount Deterioration
Common · low severityTypical onset: 40,000-70,000 mi
Symptoms: Clunking when shifting from Park to Drive, Vibration through chassis during acceleration, Excessive drivetrain movement visible when revving in park
Fix: Transmission mount replacement, sometimes both engine and trans mounts need attention together. 2-3 hours labor for trans mount alone.
Estimated cost: $400-800
Beautiful driving experience but the B48 engine failures are a legitimate concern even at low mileage—budget for potential catastrophic repair or ensure comprehensive warranty coverage before buying used.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.