The 2017 Daihatsu Copen is a kei-car roadster with a 0.66L turbo three-cylinder that's fun but fragile under sustained boost. Transmission mounts fail early, the KF-VET engine is prone to lifter/valvetrain noise and timing chain stretch, and the tiny displacement means internal wear shows up faster than conventional engines.
Transmission Mount Failure
Common · medium severityTypical onset: 40,000-70,000 mi
Symptoms: Clunking on acceleration or deceleration, Excessive driveline vibration at idle, Shifter buzz in gear
Fix: Replace both engine and transmission mounts as a pair; mount rubber degrades from heat and torque steer. Figure 2.5-3.5 hours labor due to tight engine bay access.
Estimated cost: $400-700
KF-VET Lifter/Tappet Noise and Wear
Common · high severityTypical onset: 60,000-100,000 mi
Symptoms: Cold-start ticking that may or may not disappear when warm, Loss of power and fuel economy, Check engine light with misfire codes if severe
Fix: Hydraulic lifters wear from aggressive oil change intervals or thin oil. All lifters should be replaced together with cam inspection. Cylinder head removal often required for proper access; budget 8-12 hours labor if head comes off.
Estimated cost: $1,800-3,200
Timing Chain Stretch
Occasional · high severityTypical onset: 80,000-120,000 mi
Symptoms: Rattling noise from front of engine at startup, Rough idle or hesitation, Check engine light with cam/crank correlation codes
Fix: The KF-VET uses a single-row chain prone to stretch, especially if oil changes are delayed. Replace chain, tensioner, guides, and both sprockets. Count on 6-8 hours labor; interference engine means bent valves if it skips or breaks.
Estimated cost: $1,200-2,000
Turbocharger Oil Feed Line Coking
Occasional · high severityTypical onset: 70,000-110,000 mi
Symptoms: Blue smoke on deceleration, Loss of boost pressure, Turbo whine or bearing noise
Fix: Tiny oil feed lines coke up from heat soak when engine is shut down hot. Starves turbo bearing, leading to failure. Clean or replace feed and return lines; if turbo is damaged, replacement units run $800-1,500 plus 4-5 hours labor.
Estimated cost: $1,200-2,500
Transmission Oil Cooler Leaks
Occasional · medium severityTypical onset: 50,000-90,000 mi
Symptoms: Transmission fluid spots under car, Burning smell after highway driving, Slipping or delayed shifts when hot
Fix: CVT models (if equipped) or the optional 7-speed DCT use external cooler with rubber hoses that harden and crack. Replace cooler and lines; flush transmission. 3-4 hours labor.
Estimated cost: $600-1,100
Cylinder Head Warping from Overboost or Overheating
Rare · high severitySymptoms: Persistent coolant loss with no external leaks, White smoke from exhaust, Rough running and misfires across multiple cylinders
Fix: Aggressive tuning or cooling system neglect warps the aluminum head. Requires removal, resurface (or replacement if cracked), and full gasket set. Often discover lifter wear at same time. 10-14 hours labor for full head R&R and machine work.
Estimated cost: $2,500-4,500
Buy only if meticulously maintained with records; these are high-strung toys that punish neglect, but charm when healthy.
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.