Nissan Dayz: common problems, service schedule and fuel economy
What typically goes wrong on the Nissan Dayz, at what mileage, and what keeping it right involves — from Brimly's Vehicle Knowledge Base, where every fault is checked by a human before publication.
- Years
- 2013–present
- Generations
- 2
- Engines
- 5
- Verified faults
- 5
B4xW (2nd gen, BR06, ProPilot) · 2019–present
0.66 BR06 (naturally aspirated) · 52 hp · 0.66 BR06 + smart simple hybrid (mild hybrid) · 52 hp · 0.66 BR06 turbo (Highway Star) · 64 hp
Known problems
- Worth watching usually from 31,000 mi (50,000 km)
Kei CVT sensitivity to heat and old fluid
Symptoms: shudder or slip under load, whining or delayed engagement if the CVT fluid is neglected, most likely on the turbo when worked hard
What to do: Change the CVT fluid on time and earlier under heavy city use or hot climates; treat any shudder or whine as an early signal to service the transmission. Fresh fluid is the key to CVT longevity on these kei cars.
- Good to know usually from 0 mi (0 km)
Mild-hybrid 12V and drive-belt dependence
Symptoms: the stop-start and mild-hybrid assist behave oddly, or the engine is slow to restart, if the small lithium-ion sub-battery or the belt-driven starter-generator is worn
What to do: Keep the 12V and hybrid sub-battery healthy and the accessory/starter-generator belt in good condition; have unusual stop-start behaviour scanned at a dealer. This is a gentle mild-hybrid system, not a full hybrid, so faults are usually electrical rather than drivetrain.
Service schedule
| Item | Interval | Notes |
|---|---|---|
| Cabin filter | every 9,000 mi (15,000 km) | — |
| Engine oil & filter change | every 9,000 mi (15,000 km) or 12 months | shorten to ~7,500 km for short-trip city use |
| Air filter | every 19,000 mi (30,000 km) | — |
| CVT fluid (Jatco kei CVT) important | every 25,000 mi (40,000 km) | service earlier in hot climates or heavy city use |
| Spark plugs (petrol) | every 37,000 mi (60,000 km) | shorter on the turbo |
| 12V / hybrid sub-battery check | every 24 months | the smart simple mild-hybrid system uses a small lithium-ion battery and a belt-driven starter-generator; keep the 12V and drive belt healthy |
| Brake fluid important | every 24 months | — |
B21W (1st gen, NMKV) · 2013–2019
0.66 3B20 (naturally aspirated) · 49 hp · 0.66 3B20 turbo (Highway Star) · 64 hp
Known problems
- Worth watching usually from 37,000 mi (60,000 km)
Kei CVT sensitivity to heat and old fluid
Symptoms: shudder or slip under load, whining or delayed engagement as the CVT ages without regular fluid changes, most likely on the turbo when driven hard
What to do: Change the CVT fluid on schedule (and earlier under heavy city use or in hot climates) and address any shudder or whine early. Fresh fluid is the best way to make a small kei CVT last.
- Worth watching usually from 50,000 mi (80,000 km)
Alternator and air-conditioning-compressor wear
Symptoms: charging warnings or a weak battery from a failing alternator, and loss of cooling from A/C-compressor wear, more noticeable in hot weather
What to do: Have the charging system checked if the battery keeps going flat or a charge warning appears, and treat weak air-conditioning as a compressor/system issue rather than just low gas. Budget for these as known age-related repairs on this platform.
- Worth watching usually from 62,000 mi (100,000 km)
3B20 valve-cover seal and cooling-system care
Symptoms: oil weeping into the spark-plug wells from a hardened valve-cover seal, plus a risk of overheating and head damage if the cooling system is neglected; slight oil use and chain stretch at very high mileage
What to do: Replace the valve-cover gasket if oil appears in the plug wells, keep the cooling system clean and topped up, and adjust valve clearances at the recommended interval. Watch for oil consumption and any cold-start chain rattle past ~150,000 km.
Service schedule
| Item | Interval | Notes |
|---|---|---|
| Cabin filter | every 9,000 mi (15,000 km) | — |
| Engine oil & filter change | every 9,000 mi (15,000 km) or 12 months | kei three-cylinder — shorten to ~7,500 km for short-trip city use |
| Air filter | every 19,000 mi (30,000 km) | — |
| CVT fluid important | every 25,000 mi (40,000 km) | the small kei CVT dislikes heat and old fluid; service earlier under heavy use |
| Spark plugs (petrol) | every 37,000 mi (60,000 km) | shorter on the turbo Highway Star |
| Valve clearance / timing chain check | every 62,000 mi (100,000 km) | the 3B20 benefits from a periodic valve-clearance check at high mileage; chain-driven, no belt |
| Brake fluid important | every 24 months | — |
Manufacturer-declared fuel economy
No manufacturer-declared figures for this model are in the Knowledge Base yet. A figure without the cycle it was measured under is not comparable to anything, so we publish none rather than a number you cannot interpret.
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Frequently asked
What are the most common Nissan Dayz problems?
The faults reported most often are: Kei CVT sensitivity to heat and old fluid; Alternator and air-conditioning-compressor wear; 3B20 valve-cover seal and cooling-system care. Symptoms, the mileage each appears at and what to do about it are all above.
How often does the Nissan Dayz need servicing?
Engine oil & filter change — every 9,000 mi (15,000 km) or 12 months. The full published schedule is above; your car's own service book always takes precedence.
Where does this data come from?
Brimly's Vehicle Knowledge Base — the same verified facts the app's AI assistant answers from. Every fault is written up from public sources and then checked by a human before it is published; nothing here is generated on the fly.