The priority in the creation and production of new small-displacement series belonged to Daihatsu department, but NR are most known as engines of Toyota models.
First engine of the series - 1NR-FE - introduced in 2008 for European market. It immediately replaced outdated 4ZZ-FE and then gradually supplanted 2NZ-FE and 2SZ-FE from Japanese market.
In 2010-11, simplified 2NR and 3NR for emergency markets appeared. In 2014-15, -FKE versions were introduced, working by Miller cycle (1.5 partially replaced 1NZ-FE). Since 2015, the turbocharged 8NR-FTS has been produced.
1NR-FE (1.3 EFI DVVT) - basic motor - transverse layout, multi-point injection, variable valve timing for both camshafts. Application: Toyota Auris 150..180, Corolla 150..180, Corolla Axio 160, iQ 10, Passo 30, Porte/Spade 140, Probox/Succeed 160, Ractis 120, Urban Cruiser, Verso-S, Vitz 130, Yaris 130; Daihatsu Boon, Charade; Subaru Trezia; Aston Martin Cygnet.
1NR-FKE (1.3 EFI DVVT-iE) - multi-point injection, VVT-iE and Miller cycle operation mode. Application: Toyota Ractis 120, Vitz 130; Subaru Trezia.
1NR-FBE (1.3 EFI) type'12 - multi-point injection, without variable valve timing and lash adjusters. Flex-fuel (ethanol) simplified version for Brasilian market. Application: Toyota Etios.
1NR-FBE (1.3 EFI DVVT) type'16 - multi-point injection, variable valve timing for both camshafts. Flex-fuel (ethanol) version for Brasilian market. Application: Toyota Etios, Yaris.
1NR-VE (1.3 EFI DVVT) - multi-point injection, variable valve timing for both camshafts. Daihatsu version for their own models. Application: Toyota Avanza 650; Daihatsu Xenia, Sirion; Perodua Bezza, Myvi.
2NR-FE (1.5 EFI) type'10 - multi-point injection, without variable valve timing and lash adjusters. Simplified version for Indian market. Application: Toyota Etios/Etios Cross.
2NR-FE (1.5 EFI DVVT) type'16 - multi-point injection, variable valve timing for both camshafts. Version for emergency market. Application: Toyota Etios/Etios Cross, Sienta, Vios, Yaris.
2NR-FBE (1.5 EFI) type'12 - multi-point injection, without variable valve timing and lash adjusters. Flex-fuel (ethanol) simplified version for Brasilian market. Application: Toyota Etios.
2NR-FBE (1.5 EFI DVVT) type'16 - multi-point injection, variable valve timing for both camshafts. Flex-fuel (ethanol) version for Brasilian market. Application: Toyota Etios, Yaris.
2NR-VE (1.5 EFI DVVT) type'13 - multi-point injection, variable valve timing for both camshafts. Daihatsu version for their own models. Application: Toyota Avanza 650; Perodua Aruz, Myvi.
2NR-FKE (1.5 EFI DVVT-iE) - multi-point injection, VVT-iE and Miller cycle operation mode. Application: Toyota Corolla Axio 160, Corolla Fielder 160, Porte/Spade 140, Sienta 170; Mitsuoka Ryugi.
3NR-FE (1.2 EFI) type'10 - multi-point injection, without variable valve timing and lash adjusters.
Simplified version for Indian market. Application: Toyota Etios Liva/Cross.
3NR-FE (1.2 EFI DVVT) type'13 - multi-point injection, variable valve timing for both camshafts. Application: Toyota Yaris 150.
3NR-VE (1.2 EFI DVVT) - multi-point injection, variable valve timing for both camshafts. Daihatsu version for their own models. Application: Toyota Agya/Wigo, Calya; Daihatsu Ayla, Sigra.
4NR-FE (1.3 EFI DVVT) - analogue of 1NR-FE for Chinese market. Application: Toyota Vios 150 CHN.
5NR-FE (1.5 EFI DVVT) - analogue of 2NR-VE for Chinese market. Application: Toyota Vios 150 CHN.
6NR-FE (1.3 EFI DVVT) - analogue of 1NR-FE for Chinese market. Application: Toyota Yaris 150 CHN.
7NR-FE (1.5 EFI DVVT) - analogue of 2NR-VE for Chinese market. Application: Toyota Yaris 150 CHN.
8NR-FTS (1.2 D-4T DVVT-iW) - direct injection, turbocharged, VVT-iW and Miller cycle operation mode. Application: Toyota Corolla/Auris 180, Corolla 210, C-HR.
9NR-FTS (1.2 D-4T DVVT-iW) - analogue of 8NR-FTS for Chinese market. Application: Toyota Levin 180...210 CHN.
1NR-FE (1.3 EFI DVVT)
The cylinder block - aluminum "open deck" with thin cast iron liners. The liners are fused into block and their special rough outer surface promotes strong connection. The wall thickness between the cylinders 7 mm only, no overhaul with reboring provided by manufacturer.
The axis of the crankshaft has been shifted by 8 mm relative to the cylinder axis lines (offset or "desaxage"), thus reducing the lateral component of the force exerted by the piston to the cylinder wall, reducing wear.
a - offset 8 mm, b - bore centerline, c - crankshaft centerline
There is the spacer in the water jacket installed, it allows more intensive coolant circulation near the top of the cylinder, which improves heat dissipation and helps to more evenly thermally load.
The crankshaft has 4 balance weights, narrowed journals and individual main bearing caps.
Pistons - alloy, compact T-shaped in projection, with cutted skirt. The groove for the upper compression ring is anodized, the edge of the upper compression ring and oil scraper have anti-wear PVD coating. A big drawback - piston pins are non full-floating, but press-fitted into the connecting rod. Note: for 1NR..2NR engines, Toyota officially prohibits the reuse of pistons, connecting rods and piston pins if they were disassembled.
a - resin coating, c - PVD coating
The camshafts are installed in a separate housing, which mounted on the cylinder head - it simplifies the design and manufacturing technology of cylinder head.
There are hydraulic lash adjusters and roller rockers in the valvetrain mechanism. "Indian" motors have old-style adjusting tappets.
Cooling system is classic: pump drive by outer side of serpentine belt, "cold" (80-84°C) mechanical thermostat, heated throttle body.
1 - water pump, 2 - EGR valve, 3 - throttle body, 4 - thermostat. a - to radiator, b - from radiator, c - from heater radiator, d - to heater radiator, e - from exhaust heat recirculation system, f - to exhaust heat recirculation system
The coolant pump is mounted in the timing chain cover.
Versions for cold climate area are equipped with coolant heater (by exhaust gases). In the central pipe the valve actuator with the thermostat is integrated: after cold starting gases pass through the heat exchanger, then as the valve opens and the heating gases already flow to the exhaust.
Engine is equipped with separate fan motor control unit, which allows to adjust fan speed depending on the coolant temperature, refrigerant pressure, vehicle speed and engine speed.
Intake and exhaust
Plastic intake manifold mounted at bulkhead side, steel exhaust manifold - at front side.
1 - VVT control valve (intake), 2 - VVT control valve (exhaust), 3 - ignition coil, 4 - camshaft position sensor (exhaust), 5 - air fuel ratio sensor, 6 - crankshaft position sensor, 7 - coolant temperature sensor, 8 - knock sensor, 9 - EGR valve, 10 - throttle body, 11 - fuel injector, 12 - camshaft position sensor (intake), 13 - vacuum sensor
Fuel injection - traditional multipoint, sequential under normal conditions, at low temperature and low speed grouped injection can be performed.
- Mass air flow sensor (MAF) - "hot wire" type, combined with the intake temperature sensor..
- Manifold pressure sensor (MAP) was installed in Euro 5 modifications..
- Throttle valve - fully electronically controlled (ETCS): DC motor, dual-channel non-contact position sensor (Hall effect) ETCS performs some functions of traction control (TRC) and stabilization (VSC).
- Accelerator pedal position sensor - dual-channel non-contact (Hall effect)..
- Crankshaft and camshaft position sensors - MRE type (magnetoresistive), provide a digital output signal and work properly at low engine speed.
- Knock sensor - wideband "flat" piezoelectric, unlike the old type of resonant knock sensors it feels a wider range of vibration frequencies.
- Upstream catalyst - planar type air-fuel ratio (AFS) sensor (advantage - rapid heating), downstream - normal oxygen sensor.
- Injectors with elongate nozzle are installed in the cylinder head and the fuel is injected as close as possible to the intake valves..
- Fuel supply - without return line. In addition to the pressure regulator and level gauge sensor, EVAP canister is combined with the fuel pump in the tank.
Ignition system - DIS-4 (separate coil for each cylinder). Spark plugs - thin "iridium" SG20HR11 with long threaded portion, hex 14 mm.
There are a few new features in starting system. Semi-automatic starting - it is enough to turn the key to START and release, after which the control system automatically keeps the starter on until the engine start. When the stop-start system is active, the control remembers cycle phase for each cylinder after engine stall, so at re-start the fuel and spark are supplied the cylinder which is able to join in the work immediately.
Charging system - with segment conductor alternators, 80-100A output, one-way clutch in pulley.
Continuously charging of battery is carried out during deceleration, but in steady-state mode cycles of charging and discharging of the battery are alternates for maximum efficiency. More complex control system required to use the battery temperature sensor and current sensor..
Auxiliary drive - by single serpentine belt with automatic tensioner.
• Pistons and rings with a wide variety of coatings.
b - DLC coating Diamond Like Carbon, c - chrome plating, e - resin coating, f - nitride treatment, g - DLC coating
• Updated topology of the cooling system.
1 - water pump, 2 - water inlet with thermostat, 3 - throttle body, 4 - transmission oil cooler, 5 - EGR cooler, 6 - EGR valve. a - to radiator, b - from radiator, c - from heater radiator, d - to heater radiator
• Fuel delivery pipe - steel-stamped; its walls themselves serve as a damper for fuel pressure pulsations.
1 - fuel delivery pipe, 2 - fuel injector
8NR-FTS (1.2 D-4T)
Note fundamental aspects and differences of the motor, that not like the other engines of the series.
- Variable valve timing system VVT-iW - see details.
- Implemented a possibility of engine operation in Miller / Atkinson cycle - see details.
- Strengthening cylinder block.
1 - cylinder block, 2 - thermostat (block), 3 - cylinder bore. a - water passage, b - rib, c - oil separate chamber 1, d - knock sensor boss, f - water jacket, g - breather hole, i - liner, j - bore honing.
- Crankshaft with 8 counterweights.
1 - crankshaft, 2 - thrust washer, 3 - bearing. a - micro-grooved, b - oil groove.
1 - piston, 2 - anti-friction ring carrier, 3 - upper compression ring, 4 - lower compression ring, 5 - oil ring, 6 - expander. a - combustion chamber, b - polymer coating, c - compression height, e - PVD coating, f - chrome coating.
1 - camshaft bearing cap, 2 - camshaft housing, 3 - cylinder head. c - water jacket (2-stage), d - intake port.
- Supply pump driven by additional cam of the intake camshaft.
- Vacuum pump driven by the exhaust camshaft (for brake booster operation and turbocharger control).
- Applied sodium cooled valves.
- The exhaust manifold is integrated into the cylinder head.
• Crankcase ventilation system.
The boost means as increasing the amount of crankcase bypass gases and inability to utilize it by conventional method using the intake vacuum. Therefore, the ejector is mounted in the head cover, so in boost mode gases with high content of hydrocarbons do not fall into the atmosphere but return to the intake and then burn in the cylinder.
Another separator chamber is installed to crankcase.
• The engine is equipped by two thermostats:
- Traditional thermostat (opening temperature 80-84°C) in the water inlet controls the coolant flow through the radiator
- Thermostat on the cylinder block (opening temperature 76-80°C) controls the coolant flow through the block, to maximal fast warming up
1 - oil pressure switching valve. a - closed, b - opened, c - coil, d - plunger, e - ball, f - from oil pump, g - to relief valve.
1) The oil supplied to the rear of the relief valve, cutting off the oil flow to the nozzles.
1 - relief valve, 2 - oil control valve, 3 - ECM, 4 - nozzle. a - engine oil.
2) The oil flow to relief valve end stops, the valve opens and the oil is supplied to the nozzles.
1 - relief valve, 2 - oil control valve, 3 - ECM, 4 - nozzle. a - engine oil, b - drain.
• Engine oil level sensor is installed.
1 - oil level sensor, 2 - oil level switch. a - ON, b - OFF.
Intake and exhaust
1 - turbocharger, 2 - air bypass valve, 3 - actuator, 4 - wastegate valve, 5 - coil, 6 - shaft, 7 - valve, 8 - compressor wheel, 9 - turbine wheel. c - exhaust gas, d - intake air.
Boost pressure control is performed by classic wastegate valve.
- When the engine is stopped - WGT valve open.
- When starting control valve shuts off the vacuum supply from the pump to the actuator, which in turn opens WGT. As a result, the hot exhaust gases flow directly into the converter to accelerate its warm-up.
- At low loads, when there is no need for a boost, opened WGT reduces resistance and reduces pumping losses at exhaust. By reducing the amount of residual gas the stability of the combustion process is increased.
Air bypass valve serves to prevent a situation where the sudden closing of the throttle rouse to pressure incresing between the turbocharger and the throttle, until the occurrence of reverse flow, accompanied by abnormal noise.
1 - ECM, 2 - air bypass valve, 3 - compressor wheel, 4 - turbine wheel. a - to throttle body.
• Independent turbocharger cooling circuit with an electric pump and own radiator is used.
1 - electric water pump, 2 - intercooler, 3 - turbocharger, 4 - intercooler reserve tank, 5 - intercooler radiator.
Fuel injection - direct in the combustion chamber, is synchronized with piston position. The fuel from tank pump is supplied to high pressure pump, than under pressure into the fuel rail, and finally into the cylinders by injectors. Injection can be carried out several times at the cycle.
Injection/supply pump. Single-plunger with control valve, relief valve, check valve and pulsation damper at inlet. Mounted on the valve cover and dreven by 4-lobes cam of the camshaft. The fuel pressure is regulated in the range 2.4-20 MPa depending on driving conditions.
- At inlet stroke (A) the plunger 2 moves downward and fuel draws into the pumping chamber.
- At the beginning of the compression stroke (B) part of the fuel is returned while control valve 1 is open (the specified fuel pressure is set).
- At the end of the compression stroke (C) the control valve is closed and the pressurized fuel through the check valve 3 is supplied into the fuel rail.
Fuel rail. Made of forged iron, contains fuel pressure sensor to provide feedback.
Injectors. Slotted nozzle injector injects the fuel into the cylinder as specific shaped spray that draws in a significant amount of air and increases the mass admission. Sealing teflon (PTFE) rings further reduce vibration.
To date, a comprehensive statistics on the operation of 1NR-FE engines have been accumulated (contrary to expectations, it's not so negative), while the -FKE and -FTS engines that appeared later are still at the stage of experience accumulating.
• The most famous and mass problem of 1NR-FE - is excessive oil consumption, which often appears at mileage substantially below 100 thousand kilometers. The reason is traditional for Toyota - the piston rings stuck. The need to replace pistons together with the conrods does not allow to renew the engine cheaply, but at least the cylinder block reboring is not an obligatory option.
The problem of oil consumption was recognized and described in TSB EG-0095T-1112, some production changes were implemented in early 2013. In addition to modified rings and pistons (with conrods), the valve cover and oil nozzles may have to be replaced.
• Excessive deposits of soot in the combustion chamber, on the valves and valve seats, lead to compression decrease, that causes elongated engine start (more than three seconds), which also generates DTC P1604. The defect is recognized and described in TSB EG-00037T-TME. Prescriptions are not so - install a new battery and a modified starter.
• A ticking or clattering noise from the timing chain area, more noticeable after a cold start till warming up. Recognized as "feature" and described in TSB EG-00039T-TME. Prescriptions - either do nothing, or replace the timing chain with a new one and install a modified tensioner arm.
• Rattle or knocking noise during engine operation, again due to excessive deposits in the combustion chamber. The defect is recognized and described in TSB EG-0094T-0714, some production changes implemented at the beginning of 2014. The prescriptions are almost identical to the EG-0095T-1112 - but it is recommended to replace the pistons with the next, even more modified version, and reprogram the engine ECU firmware.
• The MIL lights on with DTC P2111 or P2112. The defect is recognized and described in TSB EG-0027T-0313, some production changes implemented at the end of 2012. The prescription is to replace the throttle body assembly and update the ECU firmware.
• For 8NR-FTS engine just list a few TSBs that contain recognized defects:
EG-00014T-TME "8NR-FTS Turbo Overboost DTC P023400"
EG-00105T-TME "Rattle noise from exhaust (front) due to broken heat insulator bracket"
EG-00113T-TME "8NR-FTS Noise from the vacuum regulating valve"
EG-00094T-TME "8NR-FTS Cylinder Misfire DTC P030100, P030200, P030300, P030400, P030027, P030085" (ignition coils replacement is prescribed)
• And once again - for the health and longevity of Toyota engines (and NR in particular), it is just necessary to deactivate EGR system - some owners just reprogram the software, but plugging the gas channel with a metal plate seems to be a more reliable solution.