2018 BMW M5 F90

Typical onset: 30,000-70,000 mi

Symptoms: metallic knocking at idle that worsens with RPM, sudden loss of oil pressure, metal shavings in oil filter, engine failure without warning in severe cases

Fix: Complete engine-out teardown, crankshaft inspection/machining or replacement, all rod and main bearings, bottom-end rebuild. 40-60 labor hours if crank is reusable, up to 80+ hours for full short block replacement. Early S63TU engines (pre-2019 production) are most affected.

Estimated cost: $15,000-35,000

Typical onset: 20,000-60,000 mi

Symptoms: sudden excessive oil consumption (quart per 500-1000 mi), blue smoke on startup or under load, misfires in affected cylinder, loss of compression

Fix: Engine removal, cylinder head removal, piston replacement with updated design. Often discovered during rod bearing service. BMW issued updated pistons (PN 11258684564) for 2019+ production. 50-70 labor hours for all pistons.

Estimated cost: $18,000-28,000

Typical onset: 40,000-80,000 mi

Symptoms: transmission fluid puddles under vehicle, driver's side, burnt transmission fluid smell, transmission temperature warning on iDrive, slipping or delayed shifts if fluid level drops

Fix: Replace cooler lines and often the auxiliary cooler itself. Lines crack at crimps and mounting points due to heat cycling. 4-6 labor hours, requires transmission fluid flush after repair.

Estimated cost: $1,200-2,200

Typical onset: 50,000-90,000 mi

Symptoms: harsh clunk on aggressive 1-2 or 2-3 shifts, vibration at idle in Drive, excessive driveline movement visible during launch, transmission housing contacting crossmember in extreme cases

Fix: Replace rear transmission mount (and often front while you're in there). Mount tears internally from launch control abuse. 3-4 labor hours on a lift.

Estimated cost: $800-1,400

Typical onset: 60,000-100,000 mi

Symptoms: long crank/hard start when hot, lean fuel trim codes (2E8F, 2E90), loss of power above 4000 RPM, rough idle and misfires under load

Fix: Replace high-pressure fuel pump and filter. HPFP driven off exhaust cam, so cam follower inspection recommended. 5-7 labor hours due to intake manifold removal required for access.

Estimated cost: $2,000-3,200

Symptoms: random no-start condition, engine dies while driving without warning, intermittent crank/no-start, fault code 2A98 or 2A99 (crankshaft position implausible)

Fix: Connector located low on bellhousing, exposed to road spray. Clean and reseal connector, or replace sensor and pigtail. Preventive dielectric grease application recommended. 1-2 labor hours.

Estimated cost: $250-600