Page 3 of 2000
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.
Page 10 of 2000

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.
Page 36 of 2000

ENGINE - 2AZ-FE ENGINE
214CE04
: Conventional Type
: Flat Type
(V)
Vo l t a g e
Frequency (Hz)A
BA: Detection Band of
Conventional Type
B: Detection Band of
Flat Type
Characteristic of Knock Sensor
214CE01214CE02
Steel Weight
Insulator
Piezoelectric
ElementOpen / Short Circuit
Detection Resistor
Flat Type Knock Sensor
(Non-resonant Type)Piezoelectric
Element
Vibration Plate
Conventional Type Knock Sensor
(Resonant Type)EG-39
Knock Sensor (Flat Type)
1) General
In the conventional type knock sensor (resonant type), a vibration plate which has the same resonance
point as the knocking frequency of the engine is built in and can detect the vibration in this frequency
band.
On the other hand, a flat type knock sensor (non-resonant type) has the ability to detect vibration in a
wider frequency band from about 6 kHz to 15 kHz, and has the following features.
The engine knocking frequency will change a bit depending on the engine speed. The flat type knock
sensor can detect the vibration even when the engine knocking frequency is changed. Thus the
vibration detection ability is increased compared to the conventional type knock sensor, and a more
precise ignition timing control is possible.
2) Construction
The flat type knock sensor is installed on the engine through the stud bolt installed on the cylinder
block. For this reason, a hole for the stud bolt is running through the center of the sensor.
Inside of the sensor, a steel weight is located on the upper portion and a piezoelectric element is located
under the weight through the insulator.
The open / short circuit detection resistor is integrated.
Page 37 of 2000

ENGINE - 2AZ-FE ENGINE
214CE08
Steel Weight
Inertia
Piezoelectric
Element
214CE06
Knock Sensor
200 k
Piezoelectric
ElementOpen / Short Circuit
Detection ResistorKNK1
EKNKECM
5 V
200 k
IC
Service Tip
In accordance with the adoption of an open / short circuit detection resistor, the inspection
method for the sensor has been changed. For details, refer to the 2006 RAV4 Repair Manual
(Pub. No. RM01M1U).
To prevent the water accumulation in the connecter, make sure to install the flat type knock
sensor in the position as shown in the following illustration.
251EG12
10
10
Knock Sensor EG-40
3) Operation
The knocking vibration is transmitted to the
steel weight and its inertia applies pressure to
the piezoelectric element. The action
generates electromotive force.
4) Open / Short Circuit Detection Resistor
While the ignition is ON, the open / short circuit detection resistor in the knock sensor and the resistor
in the ECM keep constant the voltage at the terminal KNK1 of engine.
An IC (Integrated Circuit) in the ECM is always monitoring the voltage of the terminal KNK1. If the
open / short circuit occurs between the knock sensor and the ECM, the voltage of the terminal KNK1 will
change and the ECM detects the open / short circuit and stores DTC (Diagnostic Trouble Code).
Page 63 of 2000

ENGINE - 2AZ-FE ENGINE
258AS61 281EG86
Output
Voltage5 (V)
0
-100
Current+100 (A)
Characteristic of Current Sensor
288EG61C
(C) 60
Battery Temperature 0 Resistance(k
)
6 EG-66
Battery Current Sensor
Installed on the negative terminal of the battery, this sensor detects the amount of charging and discharging
amperage of the battery and sends signal to the ECM. Based on this signal, the ECM calculates the battery
capacity. A Hall IC is used for detecting the amount of charging and discharging amperage. The changes
that occur in the magnetic flux density in the core as a result of the charging and amperage of the battery
are converted and output as voltage.
Batter Temperature Sensor
The battery temperature sensor is built into the battery current sensor.
The battery characteristic (battery internal resistance) of taking in current for charging varies according
to battery electrolyte temperature. If the electrolyte temperature is too low or too high, the battery internal
resistance will increase, resulting in early deterioration. To prevent this, the battery temperature sensor
changes its resistance as shown below to detect the temperature.
Page 69 of 2000
ENGINE - 2GR-FE ENGINE
285EG05
Oil Delivery PipeCylinder Head Covers
Cylinder Head
Cover Gaskets
Oil Delivery Pipe
285EG06
Engine
FrontShim A A
For Right Bank
For Left BankA - A Cross SectionEG-73
ENGINE PROPER
1. Cylinder Head Cover
Lightweight yet high-strength aluminum cylinder head covers are used.
An oil delivery pipe is installed inside the cylinder head cover. This ensures lubrication to the sliding parts
of the roller rocker arm, improving reliability.
2. Cylinder Head Gasket
A steel-laminate type cylinder head gasket is used. A shim is used around the cylinder bore of the gasket to
help enhance sealing performance and durability.
Page 71 of 2000
ENGINE - 2GR-FE ENGINE
285EG10 285EG09
60
Knock Sensor Bosses
36.6 mm
(1.441 in.)
105.5 mm
(4.15 in.)
View from Top Side
285EG11
Wa t e r P a s s a g eEG-75
4. Cylinder Block
The cylinder block is made of aluminum alloy, so it is lightweight.
The cylinder block has a bank angle of 60, a bank offset of 36.6 mm (1.441 in.) and a bore pitch of 105.5
mm (4.15 in.), resulting in a compact block in its length and width even for its displacement.
Installation bosses of the two knock sensors are located on the inside of left and right banks.
A water passage has been provided between the cylinder bores. By allowing the engine coolant to flow
between the cylinder bores, this construction enables the temperature of the cylinder walls to be kept
uniform.
Page 77 of 2000
ENGINE - 2GR-FE ENGINE
285EG19
VVT-i
ControllerNo. 2 Camshaft
(Exhaust)
Timing
Rotor
VVT-i ControllerNo. 1 Camshaft
(Intake)
No. 3 Camshaft
(Intake)
Timing
Rotor
VVT-i Controller
VVT-i ControllerNo. 4 Camshaft
(Exhaust)Indented R portion
of cam (Profile)
Cam with indented REG-81
2. Camshaft
The camshafts are made of cast iron alloy.
An oil passage is provided on the intake and exhaust camshafts in order to supply engine oil to the VVT-i
system.
A VVT-i controller has been installed on the front of the intake and exhaust camshafts to vary the timing
of the intake and exhaust valves.
Together with the use of the roller rocker arm, the cam profile has been designed with an indented R
(radius). This results in increased valve lift when the valve begins to open and finishes closing, helping
to achieve enhanced output performance.