For more than two decades, Toyota’s 1.5 liter 1NZ-FE engine was one of their most reliable and efficient motors. While Americans never got the engine stateside, Toyota widely used the engine in the Australian, Southeast Asia, Japanese, and Taiwanese markets. It powered more than a dozen cars from 1999–2021, though it has largely fallen out of production today. Read on to find out everything you need to know about the Toyota 1NZ FE inline-four engine.
Toyota 1NZ FE Engine History
The Toyota 1NZ FE engine is part of the larger Toyota NZ engine family, which Toyota first introduced in 1997. They are probably most well known for the 1NZ-FXE, which made it stateside inside the Toyota Prius in the early-2000s. Toyota largely built the NZ line for efficiency and fuel economy rather than performance and horsepower.
During its run from 1999–2021, Toyota put the 1NZ FE inside many different vehicles, including the Allion, Auris, Corolla, Porte, Yaris, and Sienta. In addition, Toyota’s subsidiary Scion also used it in a few vehicles, including the xB, and Chinese automakers Geely and Great Wall Motors put it inside a few vehicles, too. The engine produced 109 horsepower and 105 lb-ft of torque in most models.
The engine code, 1NZ-FE, actually tells you quite a lot about the motor.
- 1 – 1st Generation Engine
- NZ – Toyota NZ Engine Family
- F – Economy Narrow-Angle DOHC Cylinder Head
- E – Multi-Point Fuel Injection
Since 2021, Toyota has largely moved on from the NZ family and the 1NZ-FE, though there are still many on the streets today. It has proven itself to be a very reliable power plant, and some people have claimed to get nearly half-a-million miles out of their 1NZ-FE before it bit the dust.
Toyota 1NZ FE Specs
|Engine Family||Toyota NZ|
|Displacement||1.5 liters (1,497 cc)|
|Configuration||Inline or Straight-4|
|Compression Ratio||10.5:1 – 11.0:1|
|Bore and Stroke||75 mm x 84.7 mm|
|Valve Train||DOHC, 16-valve- (4 val/cyl)|
|Variable Valve Timing||Yes, Intake (VVT-i)|
|Fuel System||Electronic Fuel Injection|
|Horsepower Output||109 horsepower|
|Torque Output||105 lb-ft|
Toyota 1.5L Vehicles
The Toyota 1NZ Fe engine appeared in the following vehicles:
- Allion (T240, T260)
- Auris (E150, E180)
- Corolla (E120, E140, E160)
- Porte (NP10, NP140)
- Probox (XP50)
- Raum (XZ20)
- Ractis (XP100, XP120)
- Sienta (XP80, XP170)
- Vios/Belta (XP40, XP90, XP150)
- Yaris/Echo (XP10, XP90, XP130)
- Yaris Verso/FunCargo (XP20)
- xA (XP60)
- xB (XP30, E150)
- MK (SC5)
- Great Wall
- Voleex C10
Toyota 1NZ FE Design Basics
Toyota 1NZ-FE Block, Cylinder Head, and Internals
The Toyota 1NZ FE engine is a 1.5 liter, inline or straight-4 engine. Toyota used aluminum for both the cylinder head and engine block to help reduce weight while maintaining strength. The block is an open-deck design with thin-walled, cast iron cylinder liners. Compared with older Toyota blocks, the 1NZ-FE uses a rear oil seal integrated into the engine block, opposed to a rear oil seal retainer, which helps the engine become more compact.
For the cylinder head, Toyota narrowed the angle of the exhaust and intake valves to 33.5°, which again helps the engine retain compactness. Toyota put the injectors in the intake ports of the cylinder head, which helps improve fuel economy by minimizing fuel contact against the intake port wall. The engine uses multi-port, sequential electronic fuel injection.
For the aluminum pistons, Toyota used a taper squish shape on top of the piston crown, which helps improve combustion. The crankshaft is forged steel and has five journals and 4 balance weights, and the crankshaft position sensor is actually integrated into the crankshaft itself. The connecting rods are said to be high-strength, and use plastic tightening bolts for the rod caps.
Valve Train, Manifolds, and Emissions
For the valve train, the 1NZ FE uses a dual-overhead camshaft (DOHC) design with four valves per cylinder (16-valve). The camshafts actuate the valves through a roller timing chain, and there is variable valve timing for the intake but not exhaust valves (VVT-i). This means the camshafts are slightly different, as the intake cam has a VVT-i controller on front and an oil passage to feed the controller. The intake valves measure to 30.5 mm, while the exhaust valves are 25.5 mm.
Both the manifolds use a cross-flow design to improve power and efficiency. Toyota used plastic for the intake manifold to help reduce weight and heat transfer from the cylinder head. They use long runners which helps improve the low and mid-range torque, and a torque-up resonator inside the manifold also helps. The exhaust is stainless steel and uses long-runners to also improve low and mid-range torque.
The exhaust also has a 2-way control system, which helps vary back pressure by opening and closing. This allows for quieter operation (valve closed) at lower engine speeds, while allowing for less back pressure (valve open) at higher engine speeds to increase performance. For emissions, Toyota used a 3-way catalytic converter that was thinner than previous years, but heated up quicker and had improved performance.
In 2003, Toyota made numerous updates to the 1NZ FE engine. Most of these were in response to the implementation of the Euro STEP IV Emissions Regulations, which began two years later in 2005. All engines from 2005-on had these improvements.
- Throttle Valve 100% Electronically Actuated
- Revised Piston Shape
- Revised Exhaust Manifold Shape
- Revised Catalytic Converter
- Revised ECU (16-bit to 32-bit)
- Revised Cooling System
- Added Transmission Fluid Heater (for CVT)
- Added EGR Cooler
- Added Electronically Controlled Cooling Fan
- Revised Hotter Thermostat
- New Catalytic Converter Added
- Valve Angle on Cylinder Head Narrowed (33.5° to 21°)
Horsepower and torque output remained unchanged even with the new improvements. The new improvements did not change reliability, as the engine was already pretty stout, but did encumber it with more emissions equipment, like a second catalytic converter and EGR system.
The 1NZ-FTE (Turbo)
For various Southeast Asian markets, Toyota also made a turbocharged version of the engine available, the 1NZ-FTE. This ran minimal boost pressure, but still produced 145-148 horsepower and 144 lb-ft of torque. It went from zero to 60 mph in under 8 seconds, and had a top speed of 127 mph. The engine was the same except for the turbo, and used an air-to-air intercooler to help improve performance.
Toyota 1NZ FE Reliability and Problems
Overall, the Toyota 1NZ-FE is considered an extremely reliable engine by those who have owned them. Most of them are capable of going over 200,000 miles without a full rebuild, and there are even some examples near the 500,000 mile mark.
However, the engine is far from problem free. Over the years, the 1NZ FE has shown itself to be susceptible to a few common problems, though luckily none of them are catastrophic. Most of the problems relate to the oiling system and timing chain for the VVT-i system.
Toyota 1NZ-FE Common Problems
The most common Toyota 1NZ FE Engine Problems Are:
- Oil Consumption Past 100,000 miles
- Oil Leaks
- Timing Chain Failure
- Unstable or Low Engine Speed at Idle
By far, the most common 1NZ-FE engine problem is oil consumption. This is a known issue for pretty much the entire Toyota NZ engine family, so it’s definitely not unique to the 1NZ-FE. This is typically a problem for engines once they pass the 100,000 mile mark. Generally, the oil consumption is not too bad, at about half a quart per 1,000 miles. Much of this is caused by worn piston rings from heavy usage.
In addition to oil consumption, the 1NZ FE is also prone to oil leaks in many places. The most common spots are under the timing chain cover, the timing chain tensioner, the rear crankshaft oil seal, and the crankshaft position sensor. With the oil consumption and oil leak issues, it’s a good idea to make sure you are regularly checking your oil on any high mileage 1NZ engine.
The timing chain itself is also a cause of problems due to failure. Importantly, the timing chain should be changed every 60,000-75,000 miles as part of standard maintenance. Failure to do so can result in costly valve train repairs.
The final problem we’ll address is an unstable idle or low engine speed when idling. Often, this is the problem of the throttle body, idle air control valve, MAF-sensor, or PCV valve. Many times, just cleaning the throttle body or sensors is enough to rectify the problem.
Toyota 1NZ FE Summary
Overall, the Toyota 1NZ FE engine is a solid 1.5 liter inline-four engine. Toyota produced it from 1999–2021, where they put it inside many different sedans and crossovers. The engine produced 109 horsepower and 105 lb-ft of torque in most models. It gained a reputation as a reliable and efficient engine, though one lacking really any performance. That is except for the 1NZ-FTE, the turbocharged variant, which bumped up power to 145-148 horsepower and 144 lb-ft of torque.
The 1NZ-FE never made it stateside, but earned a loyal following in the Australian, Southeast Asian, and Japanese markets. In addition to Toyota, the Chinese automakers Great Wall Motors and Geely also used authorized reproductions of the engine inside a few of their vehicles. As of 2023, the engine has largely fallen out of production from Toyota, but there are still countless roaming the streets today.
Toyota 1NZ FE FAQ
Toyota put the 1NZ FE inside many different vehicles, including the Allion, Auris, Corolla, Porte, Yaris, and Sienta. In addition, Toyota’s subsidiary Scion also used it in a few vehicles, including the xB, and Chinese automakers Geely and Great Wall Motors put it inside a few vehicles, too. The engine produced 109 horsepower and 105 lb-ft of torque in most models.
With standard maintenance, the 1NZ-FE engine is capable of more than 200,000 miles without needing a rebuild. In addition, there have even been some people who have managed to get almost 500,000 miles out of their 1NZ before any major problems kicked in.
The 1NZ-FE is the first generation of the NZ engine family, and the 2NZ-FE is the second generation of the NZ engine family. In addition, the 1NZ is a 1.5 liter motor, while the 2NZ is a 1.3 liter motor, and makes less power. However, the 2NZ won the 2000 International Engine of the Year Award from Engine Technology International.