TOYOTA RAV4 2006 Service Repair Manual

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.

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.

ENGINE - 2AZ-FE ENGINE
208EG67 DR011EG21
Exhaust Side
Intake Side A A
A - A Cross Section Injector
IN
EX
Bypass
Passage
Ta p e r S q u i s h EG-6
3. Cylinder Head
Through the adoption of the taper squish combustion chamber, the engine knocking resistance and fuel
efficiency have been improved.
An upright intake port is used to improve the intake efficiency.
Installing the injectors in the cylinder head enables the injectors inject fuel as close as possible to the
combustion chamber. This prevents the fuel from adhering to the intake port walls, which reduces HC
exhaust emissions.
The routing of the water jacket in the cylinder head has been optimized to realize the high cooling
performance. In addition, a water bypass passage has been provided below the exhaust ports to reduce the
number of parts and the weight.

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.

ENGINE - 2AZ-FE ENGINE
01NEG27Y
Irregularly shaped
outer casting
surface of linerCylinder Block
Liner A
A
A - A Cross Section
01NEG28Y
Water Jacket
Spacer Water Jacket
A - A Cross Section A
A EG-8
The liners are the spiny-type, which have been manufactured so that their casting exteriors form large
irregular surfaces in order to enhance the adhesion between the liners and the aluminum cylinder block.
The enhanced adhesion helps heat dissipation, resulting in a lower overall temperature and heat
deformation of the cylinder bores.
Water jacket spacers are provided in the water jacket of the cylinder block.
They suppress the water flow in the center of the water jackets, guide the coolant above and below the
cylinder bores, and ensure uniform temperature distribution. As a result, the viscosity of the engine oil that
acts as a lubricant between the bore walls and the pistons can be lowered, thus reducing friction.

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.

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.

ENGINE - 2AZ-FE ENGINE
286EG71
Top Dead Center
Point of Max. Speed
Bottom Dead Center
Point of
Max. SpeedPoint of
Max. Speed 90
286EG72
Inertial Force of Cylinders
No.2 and No.3
Combined Inertial Force of
All Cylinders
Unbalanced Secondary
Inertial Force
Inertial Force of Cylinder
No.1 and No.4Force
Inertial force that cannot be canceled
Crankshaft Angle -90
90270
1800- 180
Inertial Force Generated by the In-line 4 Cylinders
286EG73
090180270
A
BC
DEInertial Force of Balancer
Crankshaft Angle
Secondary Inertial Force
Mass Direction of
Balance Shaft
Inertial Force of
Balancer
Mass Direction of Balance Shaft at Crankshaft AngleEG-11
Operation
In the in-line 4-cylinder engine, the crankshaft
angle for cylinders No.1 and No.4 are exactly at
the opposite (180
) position of cylinders No.2
and No.3. Therefore, the inertial force of the
pistons and the connecting rods of the former 2
cylinders and of the latter 2 cylinders almost
cancel each other. However, because the position
at which the piston reaches its maximum speed
is located toward the top dead center from the
center of the stroke, the upward inertial force is
greater than the downward inertial force. This
unbalanced secondary inertial force is generated
twice for each rotation of the crankshaft.
To cancel the unbalanced secondary inertial force, 2 balance shafts are rotated twice for each rotation of
the crankshaft and generate inertial force in the opposite direction. Also, in order to cancel the inertial force
generated by the balance shaft itself, the balance shaft actually consists of 2 shafts rotating in opposite
directions.

ENGINE - 2AZ-FE ENGINE
240EG46 181EG10
VVT-i ControllerIntake CamshaftExhaust
Camshaft
Chain
Te n s i o n e r
Chain Damper
Chain SlipperCamshaft
Va l v e
Lifter
Service Tip
The adjustment of the valve clearance is accomplished by selecting and replacing the appropriate
valve lifters.
A total of 35 valve lifters are available in 0.02 mm (0.008 in.) increments, from 5.06 mm (0.199 in.)
to 5.74 mm (0.226 in.). For details, refer to 2006 RAV4 Repair Manual (Pub. No. RM01M1U).
EG-12
VA LV E M E C H A N I S M
1. General
The VVT-i system is used to improve fuel economy, engine performance and reduce exhaust emissions.
For details of VVT-i system, see page EG-48.
The intake and exhaust camshafts are driven by a timing chain.
Along with the increase in the amount of valve lift, the shim-less type valve lifter is used. This valve lifter
increases the cam contact surface.

ENGINE - 2AZ-FE ENGINE
181EG11
VVT-i ControllerIntake CamshaftTiming Rotor
Exhaust Camshaft
Timing Sprocket
185EG25 181EG14
Cam Spring
Cam
Plunger
SpringChain
Te n s i o n e r
Chain Damper
Oil Jet
Chain TensionerChain SlipperEG-13
2. Camshaft
The intake camshaft is provided with timing rotor to trigger the camshaft position sensor.
In conjunction with the adoption of the VVT-i system, an oil passage is provided in the intake camshaft
in order to supply engine oil pressure to the VVT-i system.
A VVT-i controller has been installed on the front of the intake camshaft to vary the timing of the intake
valves.
3. Timing Chain
A roller chain with an 8 mm (0.315 in.) pitch is used to make the engine more compact.
The timing chain is lubricated by an oil jet.
The chain tensioner uses a spring and oil pressure to maintain proper chain tension at all times.
The chain tensioner suppresses noise generated by the timing chain.
A ratchet type non-return mechanism is used.
To achieve excellent serviceability, the chain tensioner is constructed so that it can be removed and
installed from the outside of the timing chain cover.