1KR-FE engine — Toyota 1.0 (1L I3 12V DOHC VVT-i)
1L I3 12V DOHC VVT-i · 68-69 hp · 93-95 Nm
Toyota's 1KR-FE is a 1-litre three-cylinder petrol engine with 12 valves, twin cams and VVT-i, built from 2004 to 2022 with 68-69 hp and shared with PSA through the joint venture. It powers the Toyota Aygo and Yaris XP90, the Citroen C1, Peugeot 107 and 108, and the Daihatsu Boon. City cars on long oil intervals bring it in with sludged VVT-i oil galleries and cold-start rattle, chain stretch at high mileage, blue smoke from hardened valve stem seals, a carboned throttle body causing hesitation and idle hunting, a weeping water pump behind the chain cover, single-coil misfires and, on Euro 5 cars from 2010, a sticking EGR valve. Torque figures on this page cover the head bolts, crank pulley bolt, spark plugs, camshaft bearing caps, oil drain plug, main bearing caps and big-end caps.
Cold-start rattle: take the filler cap off and look for sludge before quoting chain work, because a sludged engine needs flushing before any VVT-i part goes in. Blue smoke on start-up or overrun gets a leak-down test to separate valve stem seals from rings. Coolant loss is pressure-tested before anyone mentions the head gasket, as the water pump weep hole is the usual source.
Check first
- Oil 0W-20, 2.9 L, every 10,000 km; inspect the chain at 150,000 km.
- Water pump job means the chain cover is off: fit chain, tensioner and guides at the same time.
- On C1, 107 and 108, never write adaptations with the Toyota tool; use the PSA tool.
- After throttle body cleaning or battery disconnection, idle undisturbed for 10 minutes.
- Measure head bolt length; replace the set if any exceeds 107.5 mm.
- Spark plugs every 60,000 km; worn plugs speed up coil failure.
Values cited from a licensed workshop database.
On the 1KR-FE, main bearing cap bolts: 18.5 Nm.
Engine overview
Manufacturer
Toyota / PSA joint platform (TPCA)
Displacement
1 L
Configuration
I3 12V DOHC VVT-i
Power
68-69 hp
Torque
93-95 Nm
Production years
2004-2022
Fuel type
Petrol
Vehicles with this engine
Known failures & weak points
VVT-i actuator sludging at 80,000-120,000 km: low-viscosity oil neglect causes oil galleries in the VVT-i sprocket to block, resulting in cold-start camshaft rattle lasting 3-10 seconds and P0011/P0012 DTCs. Confirm by checking oil change history — engines run on 10,000+ km intervals with cheap oil are almost always affected.
Timing chain stretch at 150,000-200,000 km: the single-row primary chain and plastic tensioner guides wear, producing a metallic rattle on cold start that clears within 30 seconds. Left unaddressed, the chain can skip a tooth causing valve-to-piston contact.
Oil consumption via valve stem seals at 100,000-160,000 km: hardened valve stem seals cause blue smoke on cold start and overrun, consumption up to 0.5L/1,000 km. Seals are accessible with head on engine using a valve spring compressor and air-line adapter to hold valves. Do NOT confuse with piston ring consumption — perform cylinder leak-down test first to differentiate.
Throttle body carbon fouling at 60,000-100,000 km: the drive-by-wire throttle body accumulates heavy carbon deposits on the butterfly and bore due to the absence of a catch-can on the PCV system. Symptoms include rough idle, hesitation 1,500-2,500 rpm, and idle hunt. Clean with throttle body cleaner and soft brush; requires idle relearn procedure via OBD (close throttle, ignition on 2 min, or Toyota Techstream idle reset). Do NOT spray cleaner into a running engine on this unit — the plastic butterfly pivot is fragile.
Coolant loss via water pump weep hole at 90,000-130,000 km: the mechanical water pump impeller seal fails, initially showing as a white residue trail below the pump weep hole before progressing to active drip. Often misdiagnosed as head gasket. Pressure-test cooling system first. Water pump replacement requires timing chain cover removal — always replace chain tensioner and guides simultaneously as labor overlap is near-total.
Individual ignition coil packs fail intermittently, causing single-cylinder misfire (P030X) codes, rough running and increased fuel consumption. Check spark plug condition, since worn plugs accelerate coil failure on this engine.
EGR valve sticking on Euro 5 variants from 2010 onward at 70,000-110,000 km: carbon buildup causes EGR valve to stick open or partially open, resulting in rough idle, P0401/P0402 codes, and poor low-rpm response. Remove and clean with EGR cleaner; Inspect EGR cooler for internal cracking simultaneously — coolant contamination in intake is a secondary failure mode on high-mileage units.
Crankshaft position sensor failure at 100,000-180,000 km: the reluctor ring on the crankshaft and the CKP sensor gap are sensitive to oil contamination from the rear main seal. Symptoms include intermittent no-start, stalling at idle, and P0335/P0336 codes. Rear main seal replacement is straightforward (sump drop not required on most variants); Confirm by checking for oil contamination on sensor tip before condemning ECU.
Common torque specifications
| Head Bolts | Step 1: 30 Nm; Step 2: +90° angle; Step 3: +90° angle. TTY bolts — replace on every removal. Total 4 bolts M10. Verify bolt length before reuse (max stretch limit 107.5 mm). unconfirmed |
|---|---|
| Crank Pulley Bolt | 185 Nm (single-use bolt; replace on removal; use flywheel locking tool SST 09213-54015 or equivalent) unconfirmed |
| Spark Plugs | 20 Nm (NGK ILKAR7L11 iridium OEM; gap 1.0-1.1 mm; replace every 60,000 km) unconfirmed |
| Camshaft Bearing Caps | 13 Nm (tighten in sequence from center outward; do not exceed — caps are aluminum and crack easily) unconfirmed |
| Oil Drain Plug | 35 Nm (M14x1.5; replace crush washer every drain) unconfirmed |
| Main Bearing Cap Bolts | 18.5 Nm |
Figures marked unconfirmed could not be cross-checked against a workshop source. Verify against the vehicle’s own documentation before tightening.
Factory specifications
Values from the manufacturer documentation for this engine.
Engine (general)
| Engine code | 1KR-FE |
| Capacity | 998 cc |
| Idle speed | 750 - 900 (900 - 1050) rpm |
| Inlet | 0.19 ± 0.045 mm |
| Exhaust | 0.32 ± 0.045 mm |
| Normal | 14.2 bar |
| Minimum | 10.8 bar |
| Differential limit between cylinders | < 1.5 bar |
| Oil pressure | 0.3 / 750 2.0 / 3000 bar/rpm |
| Idle speed | 790-890 rpm |
| Inlet | 0.14-0.23 mm |
| Exhaust | 0.27-0.36 mm |
| Differential limit between cylinders | 1.5 bar |
Engine (petrol)
| Fuel system (make and type) | EFi |
| Timing stroboscopic (before TDC) | 10 ± 2 / 750-900 °/rpm |
| Spark plugs (make and type) | Denso SK20HR11 NGK ILFR6C 11 |
| Spark plug gap | 1.0 - 1.1 mm |
| Injection pressure/system pressure | 3.24 ± 0.05 bar |
| CO exhaust gas | < 0.2 % |
| HC | < 200 ppm |
| Fuel system (make and type) | Bosch ME 7.9.5 |
| Number of cylinders | 3 |
| Firing order | 1- 2 - 3 |
| Ignition type | DIS |
| Timing stroboscopic (before TDC) | 8-12 / 790-890 °/rpm |
| Spark plugs (make and type) | DENSO K20HR-U11 |
| Spark plug gap | 1.1 mm |
| Injection pressure/system pressure | 3.1-3.5 bar |
| HC | < 70 ppm |
| Lambda | 0.97 – 1.03 |
| CO at fast-idle speed | < 0.3 % |
Cooling system
| Cap pressure | 1.08 ± 0.15 bar |
| Thermostat opens at | 82 ± 2 °C |
| Cap pressure | 1.4 bar |
| Thermostat opens at | 77 °C |
| Stage 1/Fan 1 | 92 °C |
Electrical
| Battery | 28 Ah |
| Alternator | 65 A |
| Alternator | 70 80 A |
Capacities
| Engine sump, incl. filter | 3.1 l |
| Gearbox refill | 2.2 l |
| Gearbox refill after overhaul | 5.0 l |
| Air-conditioner refrigerant | 300 ± 30 g |
| Manual transmission | C551 |
| Gearbox refill | 1.7 l |
| Cooling system | 4.0 l |
| Air-conditioner refrigerant | 420-480 g |
| Air-conditioner compressor oil | 80 (Zexel DV-06R) ml |
Torque settings
| Cylinder head bolts — Stage 1 | 32 ± 2 Nm |
| Cylinder head bolts — Stage 2 | 180 ° |
| Oil plug | 30 Nm |
| Main bearing cap | 59 ± 6 Nm |
| Big-end bearing cap — Stage 1 | 15 Nm |
| Big-end bearing cap — Stage 2 | 90 ± 10 ° |
| Wheel nuts | 103 ± 14 Nm |
| Front hub | 196 ± 29 Nm |
| Cylinder head bolts — Stage 1 | 32 Nm |
| Spark plugs | 25 Nm |
| Main bearing cap | 60 Nm |
| Big-end bearing cap — Stage 2 | 90 ° |
| Front hub | 216 Nm |
| Wheel bearing unit to axle | 56 Nm |
| Wheel bolts | 103 Nm |
Emissions
| Emission code | 70/220*2003/76B |
| Emission standard | Euro 4 |
| CO2 average | 106 - 108 g/km |
| CO | 0.320 - 0.370 g/km |
| HC | 0.040 - 0.050 g/km |
| NOx | 0.010 - 0.020 g/km |
Workshop procedures for this engine
Step-by-step procedures from the workshop database.
- Toyota Aygo 1.0 1KR-FE timing chain replacement
- Aygo 1.0 1KR-FE (C551)
- Toyota Aygo 1.0 C551A 1KR-FE clutch replacement
- Toyota Aygo 1.0 VVT-i 1KR-FE gearbox removal & installation
- Peugeot 107 1.0 1KR-FE timing chain replacement
- Daihatsu Cuore, Charade, Sirion 2_1.0 timing chain replacement
- Toyota Yaris 2005, 2011 1.0 1KR-FE timing chain replacement
- Toyota Yaris 2005 1.0 1KR-FE gearbox removal & installation
- Toyota Yaris 2011 1.0 1KR-FE gearbox removal & installation
- Toyota Yaris 1.0 C551A 1KR-FE gearbox removal & installation
Service intervals
| Timing Chain | Inspect at 150,000 km; no OEM replacement interval specified but replace on noise or stretch evidence. Chain is NOT lifetime on high-mileage examples. |
|---|---|
| Oil Change Km | 10000 |
| Oil Spec | 0W-20 or 5W-30 ACEA A1/B1 or Toyota Genuine Motor Oil 0W-20 (preferred for VVT-i health; 5W-30 acceptable in high-mileage engines with consumption) |
| Oil Capacity L | 2.9 |
| Coolant Spec | Toyota Super Long Life Coolant (SLLC) pink/red, pre-mixed 50/50, or OAT coolant meeting Toyota TSK-2601G; change interval 160,000 km or 10 years first, then every 80,000 km |
Pro tips from the field
The VVT-i oil feed on this engine is critically dependent on oil cleanliness. When diagnosing cold-start rattle, always remove the oil filler cap and inspect for mayonnaise or heavy sludge before quoting chain work — a sludged engine needs a full flush protocol (two short-interval oil changes with flushing oil) before any VVT-i component replacement, otherwise the new actuator will fail within 20,000 km.
When replacing the water pump, the timing chain cover must come off. At this point the additional cost of a full chain kit (chain, tensioner, both guides) is only 1h extra labor. Any shop that replaces the water pump alone without addressing chain wear on a 100,000+ km engine is setting the customer up for a repeat job within 30,000 km. Always upsell the chain kit on this overlap.
The idle relearn procedure after throttle body cleaning or battery disconnect is mandatory and often skipped: connect OBD scanner, clear adaptations, start engine cold, allow to idle without touching throttle for 10 minutes. Without this, the ECU idle trim will hunt for 200-300 km causing customer comebacks. Toyota Techstream has a dedicated 'Idle Speed Control Reset' function; generic OBD tools can achieve the same by clearing long-term fuel trims.
On PSA-badged variants (C1/107/108), the ECU calibration is Toyota hardware but PSA-flashed. Do NOT attempt to use Toyota Techstream for ECU programming on these — use Lexia/Diagbox for Citroen or Planet for Peugeot. Techstream will read live data correctly but will corrupt the PSA ECU if used for adaptation writes. This is a common and expensive mistake in mixed-fleet workshops.
Cylinder head bolt TTY status is often overlooked on this engine because the bolts look reusable. Measure each bolt's free length against the manufacturer's service limit — any bolt beyond spec means the full set should be replaced, since reusing stretched TTY bolts risks head gasket failure soon after a rebuild.
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TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
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The story behind TorqFix →Workshop data on this page last updated 22 Aug 2026.