2016 BMW I3

Typical onset: 40,000-80,000 mi

Symptoms: range extender won't start or runs rough, Check Engine light with misfire codes, reduced REx power output, fuel smell in cabin when REx operates

Fix: The 647cc two-cylinder REx motor runs infrequently and accumulates carbon on valves and pistons. Severe cases require engine removal and rebuild (8-12 hours labor). Preventive: run REx monthly for 20+ minutes at highway speed. Extended warranty claims common but often denied after 50k. Some shops do walnut blasting intake valves without full removal (4-6 hours).

Estimated cost: $3,500-7,500

Typical onset: 60,000-100,000 mi

Symptoms: won't charge on Level 2 AC (DC fast charging still works), drivetrain malfunction warning, charge port light flashes yellow/red, no response when plugged in

Fix: The KLE (Kombilader Einheit) converts AC to DC for battery charging. Failure is total—car won't charge at home. Part is under the frunk, requires bumper removal and refrigerant recovery if A/C lines interfere. 4-6 hours labor. BMW extended some warranties to 8yr/100k for this specific part due to high failure rate. Used units available but risky.

Estimated cost: $2,800-4,500

Typical onset: 50,000-90,000 mi

Symptoms: clunk when accelerating or decelerating, vibration through floor at low speeds, loud bang shifting from Drive to Reverse, visible rubber separation on motor mounts

Fix: The electric motor mounts fail from torque loads—instant electric torque is hard on rubber mounts. Front and rear motor mounts typically go first. Rear requires subframe drop (6-8 hours). Front is easier (2-3 hours). Most shops replace both sides while in there. Polyurethane aftermarket options last longer but add NVH.

Estimated cost: $1,200-2,800

Symptoms: car completely dead, won't unlock or start, drivetrain malfunction warning, random error messages about charging system, car won't go into Ready mode even with full HV battery

Fix: The i3 uses a small 12V AGM battery in the frunk to run computers and contactors—if it dies, the entire car is bricked even with 100% main battery. BMW's OE battery is undersized and fails every 3-4 years (worse in hot climates). Replacement is simple (0.5 hours) but requires registration/coding with proper scan tool or car throws faults. Preventive replacement at 3 years saves tows.

Estimated cost: $350-600

Typical onset: 70,000-120,000 mi

Symptoms: reduced power warning during acceleration, drivetrain malfunction light, car enters limp mode in hot weather or after sustained highway driving, error codes for inverter temperature

Fix: The inverter (EME unit) can overheat due to internal capacitor degradation or coolant flow issues in the electric drive cooling loop. Sometimes it's just low coolant or air in system (1 hour bleed procedure). Full inverter replacement requires motor removal (10-14 hours). BMW issued software updates to derate power proactively when temps climb. Check coolant level in electric system reservoir first—separate from REx coolant.

Estimated cost: $4,500-8,000

Typical onset: 80,000-120,000 mi

Symptoms: significantly reduced range (below 60 miles on 22 kWh pack), battery conditioning takes longer, kapa max (state of health) below 70% on scan tool, uneven cell voltages visible in diagnostics

Fix: The 2016 has the smaller 22 kWh Samsung SDI pack (60 Ah cells). Capacity loss is expected but some packs degrade faster due to repeated DC fast charging or hot climate exposure. BMW warranty covered 8yr/100k for 70% capacity but most 2016s are out of warranty now. Individual module replacement is possible (16 hours labor, $2k-4k per module) but often not economical vs. used pack swap. BimmerCode can show real kapa max percentage.

Estimated cost: $8,000-15,000