Page 1 of 2000

ENGINE - 2AZ-FE ENGINE EG-4
FEATURES OF 2AZ-FE ENGINE
The 2AZ-FE engine has achieved the following performance through the use of the items listed below.
(1) High performance and reliability
(2) Low noise and vibration
(3) Lightweight and compact design
(4) Good serviceability
(5) Clean emission and fuel economy
Section
Item(1)(2)(3)(4)(5)
Engine
A cylinder block made of aluminum alloy along with a
magnesium alloy die-cast cylinder head cover is used.
Engine
ProperA taper squish shape is used for the combustion chamber.p
A resin gear balance shaft is used.
Vl
A timing chain and chain tensioner are used.
Va l v e
MechanismThe shim-less type valve lifters are used.MechanismThe VVT-i system is used.
A chacoal filter is used in the air cleaner cap.
Intake andIntake manifold made of plastic is used.Intake and
ExhaustThe linkless-type throttle body is used.
SystemA thin-wall ceramic TWC (Three-Way Catalytic converter)
is used.
The fuel returnless system is used.
Fuel
System
Quick connectors are used to connect the fuel hose with the
fuel pipe.
System12-hole type fuel injectors with high atomizing performance
are used.
Ignition
SystemIridium-tipped spark plugs are used.
Charging
SystemThe segment conductor type generator is used.
Starting
SystemPS (Planetary reduction-Segment conductor motor) type
starter is used.
The ETCS-i is used.
Engine
Control
The DIS (Direct Ignition System) makes ignition timing
adjustment unnecessary.
Control
SystemThe non-contact type sensor is used in the throttle position
sensor.
The planar type air-fuel ratio sensor is used.
Page 2 of 2000
ENGINE - 2AZ-FE ENGINE
DR011EG20
Cylinder Head Cover
Cylinder Head Cover Gasket
02AEG02Y 02AEG01Y
Cylinder
Bore Side
FrontOuter
Side
Shim A
A
A - A Cross SectionEG-5
ENGINE PROPER
1. Cylinder Head Cover
A lightweight magnesium alloy die-cast
cylinder head cover is used.
Acrylic rubber, which excels in heat resistance
and reliability, is used for the cylinder head
cover gasket.
2. Cylinder Head Gasket
A steel-laminate type cylinder head gasket is used. A shim has been added around the cylinder bore to
increase the sealing surface, thus improving the sealing performance and durability.
Page 4 of 2000

ENGINE - 2AZ-FE ENGINE
DR011EG22 01NEG26Y
Air Flow During Engine Revolution
Wa t e r P u m p
Swirl Chamber
Crankshaft
Bearing Cap
Plastic Region
Tightening BoltsThermostat Housing
Air Conditioning
Compressor BracketsAir Passage Holes
Air Flow
NOTICE
Never attempt to machine the cylinder because it has a thin liner thickness.
EG-7
4. Cylinder Block
Lightweight aluminum alloy is used for the cylinder block.
By producing the thin cast-iron liners and cylinder block as a unit, compaction is realized.
Air passage holes are provided in the crankshaft bearing area of the cylinder block. As a result, the air at
the bottom of the cylinder flows smoother, and pumping loss (back pressure at the bottom of the piston
generated by the piston’s reciprocal movement) is reduced to improve the engine’s output.
The oil filter and the air conditioning compressor brackets are integrated into the crankcase. Also, the
water pump swirl chamber and thermostat housing are integrated into the cylinder block.
Page 6 of 2000
ENGINE - 2AZ-FE ENGINE
01MEG01Y
Taper Squish Shape : Resin Coating
240EG45
Plastic Region Tightening BoltsEG-9
5. Piston
The piston is made of aluminum alloy and skirt area is made compact and lightweight.
The piston head portion uses a taper squish shape to improve the fuel combustion efficiency.
The piston skirt has been coated with resin to reduce the friction loss.
6. Connecting Rod
The connecting rods and caps are made of
high-strength steel for weight reduction.
Nut-less type plastic region tightening bolts are
used on the connecting rod for a lighter design.
The connecting rod bearings are reduced in
width to reduce friction.
Page 7 of 2000
ENGINE - 2AZ-FE ENGINE
01NEG31Y
No.1 JournalBalance Shaft Drive Gear
Oil Hole
Crank Pin
Balance Weight
01NEG32Y
: Resin Gear
Balance Shaft
HousingBalance Shaft No.1 Balance Shaft No.2Crankshaft
Balance Shaft Drive Gear EG-10
7. Crankshaft
The forged crankshaft has 5 journals and 8 balance weights.
The crankshaft is made of forged steel.
Pin and journal fillets are roll-finished to maintain adequate strength.
The balance shaft drive gear is provided for the crankshaft.
8. Balance Shaft
General
A balance shaft is used to reduce vibrations.
The crankshaft directly drives the No. 1 balance shaft.
In addition, a resin gear is used on the driven side to suppress noise and offer lightweight design.
Page 20 of 2000
ENGINE - 2AZ-FE ENGINE
185EG16
Pulsation
Dumper
Pressure Regulator
Fuel Pump
AssemblyFuel Tank
Fuel Filter
Fuel Pump
DR011EG18
EG-23
2. Fuel Returnless System
Fuel returnless system is used to reduce the evaporative emission. As shown below, by integrating the fuel
filter and pressure regulator with fuel pump assembly, the fuel return system in which the fuel returns from
the engine area is discontinued and temperature rise inside the fuel tank is prevented.
3. Fuel Injector
The 12-hole type injector is used. By modifying its
injector nozzle to a taper shape, this injector has
achieved high atomizing performance of fuel. In
addition, the injector provides good performance
with the lightweight moving parts and the
optimized magnetic circuit.
Page 22 of 2000

ENGINE - 2AZ-FE ENGINE
206EG40206EG41
206EG42
Stator Segment
ConductorStator
Joined
Joined Segment
Conductor SystemSegment
ConductorStator
StatorConductor
Wire
Conductor Wire
A
AA - A Cross
Section
Segment Conductor Type GeneratorB
BB - B Cross
Section
Conventional Type GeneratorWinding System
Stator
Segment
Conductor
Cross Section
Stator of Segment Conductor Type GeneratorEG-25
CHARGING SYSTEM
1. Segment Conductor Type Generator
A compact and lightweight segment conductor type generator that generates high amperage output in a
highly efficient manner is used.
This generator has a joined segment conductor system in which multiple segment conductors are welded
together to form the stator. Compared to the conventional winding system, the electrical resistance is
reduced due to the shape of the segment conductors, and their arrangement helps to make the generator
compact.
Specifications
Ty p eSE0
Rated Voltage12 V
Rated Output100 A
Initial Output Starting SpeedMax. 1,500 rpm
Page 24 of 2000

ENGINE - 2AZ-FE ENGINE
01NEG46Y
ArmatureSurface Commutator
Permanent Magnet
Brush
LengthEG-27
STARTING SYSTEM
1. General
A compact and lightweight PS (Planetary reduction-Segment conductor motor) type starter is used.
Because the PS type starter contains an armature that uses square-shaped conductors, and its surface
functions as a commutator, it has resulted in both improving its output torque and reducing its overall
length.
In place of the field coil used in the conventional type starter, the PS type starter uses two types of
permanent magnets: main magnets and interpolar magnets. The main magnets and interpolar magnets
have been efficiently arranged to increase the magnetic flux and to shorten the length of the yoke.
Specifications
Starter TypePS Type
Rating Output1.7 kW
Rating Voltage12 V
Length*1mm (in.)128 (5.04)
Weight g (lb)2950 (6.50)
Rotational Direction*2Counterclockwise
*1: Length from the mounted area to the rear end of the starter
*
2: Viewed from pinion side