The 2017 Honda S660 is a Japan-domestic-market kei sports car with a mid-mounted turbocharged 660cc three-cylinder. It's generally reliable by Honda standards, but the compact high-strung engine and CVT transmission have their quirks, particularly as mileage climbs past 60k.
CVT Transmission Judder and Mount Failure
Common · medium severityTypical onset: 40,000-80,000 mi
Symptoms: Shudder or vibration during acceleration from a stop, Clunking noise when shifting from park to drive, Excessive engine movement visible from cabin during throttle application
Fix: Transmission mounts wear prematurely due to mid-engine layout and torque pulses from the turbo three-cylinder. Replacing all mounts takes 3-4 hours. CVT judder may require fluid flush with genuine Honda CVTF or, in severe cases, internal CVT clutch pack replacement (8-10 hours labor).
Estimated cost: $400-800 for mounts alone; $2,500-4,000 if CVT internals need work
Timing Chain Stretch and Lifter Noise
Occasional · high severityTypical onset: 80,000-120,000 mi
Symptoms: Cold-start rattle that persists beyond 10 seconds, Check engine light with P0016 or P0017 cam/crank correlation codes, Ticking noise from valve cover area under load
Fix: The S07A engine uses a timing chain that can stretch, causing valve timing to drift. Hydraulic lifters also wear and collapse. Full timing chain replacement with tensioner, guides, and all 6 lifters requires cylinder head removal in this mid-engine bay—figure 10-12 hours labor. Head resurface adds 2 hours and $150-300.
Estimated cost: $2,800-4,500 including head gasket set and lifters
Turbocharger Wastegate Rattle
Occasional · low severityTypical onset: 60,000-100,000 mi
Symptoms: Rattling or buzzing noise at idle that disappears under boost, Slight drop in boost pressure or sluggish throttle response, No check engine light in early stages
Fix: The wastegate actuator rod or internal flapper can develop play. Not safety-critical but annoying. Turbo replacement or rebuild is 5-6 hours due to mid-engine access. Aftermarket rebuilds run cheaper than OEM Honda units.
Estimated cost: $1,200-2,200 for turbo replacement; $600-900 for rebuild if core is good
Fuel Filter Clogging and Fuel Pressure Irregularity
Occasional · medium severityTypical onset: 50,000-90,000 mi
Symptoms: Hesitation or stumble under hard acceleration, Rough idle or surging at cruise, Check engine light with lean fuel trim codes
Fix: The in-tank fuel filter isn't a traditional service item in Honda's manual, but contamination in JDM fuel systems (or older gas) can clog it. Requires fuel pump module removal—2.5 hours. Also inspect fuel pressure regulator and injectors.
Estimated cost: $350-650 for filter and pump module service
Transmission Oil Cooler Line Leaks
Rare · medium severityTypical onset: 70,000-110,000 mi
Symptoms: Small puddle of reddish fluid under mid-section of car, CVT overheat warning light on spirited drives or track days, Burnt smell from transmission area
Fix: Rubber cooler lines from CVT to front-mounted cooler can crack or chafe. Access is tight. Line replacement takes 2-3 hours plus CVT fluid refill. Not common but catastrophic if CVT runs dry.
Estimated cost: $400-700 including fluid
Harmonic Balancer Degradation
Rare · high severityTypical onset: 100,000+ mi
Symptoms: Visible wobble on crankshaft pulley at idle, Serpentine belt wear or belt squealing, Vibration felt through chassis at all RPM ranges
Fix: The rubber damper ring can separate from the hub. If it fails completely, catastrophic timing chain or accessory belt damage follows. Replacement is 2-3 hours but requires careful torque procedure on crankshaft bolt.
Estimated cost: $500-900
Buy one if you want a unique micro sports car and can wrench or budget $1,000/year beyond maintenance; avoid high-mileage examples without full service records, especially CVT and timing chain history.
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.