2018 SMART FORTWO

Typical onset: 40,000-80,000 mi

Symptoms: Harsh shifts or lurching during acceleration, Transmission slipping into neutral unexpectedly, Clutch shudder at low speeds, Check engine light with transmission codes, Complete loss of drive engagement

Fix: The 6-speed dual-clutch (Twinamic) fails prematurely due to mechatronic unit issues and clutch pack wear. Most shops recommend full transmission rebuild or replacement. Labor runs 8-12 hours due to tight engine bay access. Transmission mounts also fail from the constant stress, adding another 2-3 hours if addressed simultaneously.

Estimated cost: $4,500-7,500

Typical onset: 60,000-100,000 mi

Symptoms: Loss of boost pressure and power, Blue or white smoke from exhaust, Whistling or whining noise during acceleration, Oil consumption increases noticeably, Check engine light with turbo underboost codes

Fix: The small BorgWarner turbo runs at extreme boost levels for the displacement and fails from bearing wear or wastegate actuator issues. Replacement requires removing significant engine bay components in the cramped rear-engine layout. Figure 6-8 hours labor plus turbo unit.

Estimated cost: $2,200-3,500

Typical onset: 70,000-120,000 mi

Symptoms: Coolant loss with no visible leaks, White smoke from exhaust, Overheating issues, Rough idle or misfires, Coolant contamination in oil (milky dipstick)

Fix: The aluminum cylinder head develops cracks between valve seats or in coolant passages, often from thermal cycling and high cylinder pressures from the turbo. Requires complete head removal, pressure testing, and typically replacement since cracks rarely weld successfully. Expect 12-16 hours labor in the rear-engine configuration.

Estimated cost: $3,800-5,500

Symptoms: One or both headlights completely out, Flickering or intermittent operation, DRL or turn signal within headlight not functioning, Moisture visible inside lens assembly

Fix: The integrated LED modules fail from water intrusion or internal ballast failure. Smart charges dealer prices ($1,200+ per side) for assemblies. Aftermarket options exist but quality varies. Labor is minimal at 0.5-1 hour per side, but parts drive the cost. This is age/heat-related, not mileage.

Estimated cost: $800-2,400

Typical onset: 60,000-100,000 mi

Symptoms: Reduced range (below 50 miles on full charge), Rapid charge level drops under load, Battery warning lights, Charging takes longer than normal, Climate control significantly impacts range

Fix: The 17.6 kWh lithium-ion battery loses 20-30% capacity by 80,000 miles with typical use. Mercedes-Benz charges $13,000-15,000 for replacement, but refurbished packs run $5,000-8,000. Labor is 4-6 hours to remove rear subframe and swap battery assembly. Some owners live with reduced range rather than replace.

Estimated cost: $6,000-9,500

Typical onset: 50,000-90,000 mi

Symptoms: Vehicle pulls to one side when braking, Excessive heat from one wheel, Premature pad wear on one side, Burning smell after driving, Reduced fuel economy (gas) or range (electric)

Fix: The single-piston sliding calipers seize from corrosion on the slider pins and piston, especially in salt-belt states. Rebuilds rarely last; replacement is standard practice. Each caliper takes 1-1.5 hours including proper bedding procedure. Often both sides need attention simultaneously.

Estimated cost: $600-1,200

Typical onset: 70,000-110,000 mi

Symptoms: Transmission fluid spots under vehicle, Transmission overheating warnings, Burning smell from engine bay, Fluid level drops between services, Harsh shifting when transmission is hot

Fix: The external oil cooler for the dual-clutch develops leaks at the line connections or through the core itself. Access requires partial engine disassembly from the rear. Replacement takes 3-5 hours depending on how much must be removed. Often discovered during transmission service.

Estimated cost: $800-1,400