piston TOYOTA RAV4 2006 Service Repair Manual

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
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
208EG07
VVT-i Controller
Camshaft Timing
Oil Control Valve
Oil Return
Hole
Oil PumpOil Filter Chain
Te n s i o n e r
01NEG33Y
Bypass
Va l v e
Relief
Va l v eMain Oil Hole
Oil Filter
Oil Pump
Oil StrainerChain
Te n s i o n e rCylinder Head
Exhaust
Camshaft
Journal
Oil Control
Va l v e
VVT-i Controller
Oil Pan
Intake
Camshaft
Journal
Crankshaft
Journal
Crankshaft
Pin
Oil Jet
Piston
Cylinder
Block
Barance
Shaft
Timing
Chain EG-14
LUBRICATION SYSTEM
1. General
The lubrication circuit is fully pressurized and oil passes through an oil filter.
The trochoid gear type oil pump is chain-driven by the crankshaft.
The oil filter is attached downward from the crankcase to improve serviceability.
Along with the adoption of the VVT-i system, the cylinder head is provided with a VVT-i controller and
a camshaft timing oil control valve. This system is operated by the engine oil.
Oil Circuit

ENGINE - 2AZ-FE ENGINE
01NEG34Y
Oil Jets
Check
Va l v e
Oil
Bottom Side View Oil Jet Cross SectionEG-15
Oil Capacity
Liters (US qts, Imp. qts)
Dry
5.0 (5.3, 4.4)
with Oil Filter4.3 (4.5, 3.8)
without Oil Filter4.1 (3.8, 3.1)
2. Oil Jet
Piston oil jets for cooling and lubricating the pistons are used in the cylinder block.
These oil jets contain a check valve to prevent oil from being fed when the oil pressure is low. This prevents
the overall oil pressure in the engine from dropping.

ENGINE - 2GR-FE ENGINEEG-71
FEATURES OF 2GR-FE ENGINE
The 2GR-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
Item
(1)(2)(3)(4)(5)
A steel laminate type cylinder head gasket is used.
An upright intake port is used.
EngineA taper squish shape is used for combustion chamber.Engine
ProperA cylinder block made of aluminum alloy is used.Proper
The skirt portion of the piston is applied with resin to
reduce friction.
An oil pan No. 1 made of aluminum alloy is used.
The Dual VVT-i (Variable Valve Timing-intelligent)
system is used.
Va l v e
Mh i
Hydraulic lash adjusters are used.
MechanismTiming chains and chain tensioners are used.
Roller rocker arms are used.
Lubrication
SystemAn oil filter with a replaceable element is used.
Cooling SystemThe TOYOTA Genuine SLLC (Super Long Life Coolant)Cooling SystemThe TOYOTA Genuine SLLC (Super Long Life Coolant)
is used for the engine coolant.
The linkless-type throttle body is used.
Intake andThe intake air chamber made of plastic is used.Intake and
Exhaust
S
A stainless steel exhaust manifold is used.
SystemAn ultra thin-wall, high-cell density ceramic type TWC
(Three-Way Catalytic converter) is used.
The fuel delivery pipe made of plastic is used.
Fuel SystemA compact 12-hole type injector is used.Fuel SystemQuick connectors are used to connect the fuel hose with
the fuel pipe.
Ignition System
The DIS (Direct Ignition System) makes ignition timing
adjustment unnecessary.
Ignition System
The long-reach type spark plugs are used.
(Continued)

ENGINE - 2GR-FE ENGINE
285EG12
Liner
Cylinder
Block
Irregularly shaped
outer casting
surface of liner A
A
A - A Cross Section
285EG13
Front MarkResin CoatingTaper Squish Shape
Alumite
Coating EG-76
A compact block has been achieved by producing the thin cast-iron liners and cylinder block as a unit. It
is not possible to bore the block with this liner.
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 improve heat dissipation, resulting in a lower overall temperature and heat
deformation of the cylinder bores.
5. Piston
The piston is made of aluminum alloy.
The piston head portion uses a taper squish shape to accomplish fuel combustion efficiency.
The piston skirt is coated with resin to reduce the friction loss.
The groove of the top ring is coated with alumite to ensure wear resistance.
By increasing the machining precision of the cylinder bore diameter, the outer diameter of the piston is
made into one size.

ENGINE - 2GR-FE ENGINE
285EG24
Timing Chain Cover
Oil Pump
Housing
Oil Pump Rotors
(Cycloid Rotor)Crankshaft
To Cylinder
Block
From Oil
Filter
To
Oil FilterFrom
Oil Strainer
Oil passage in the oil pump
285EG25
Oil Jet Cross Section
Oil JetsCheck
Va l v eEngine Oil EG-86
2. Oil Pump
A compact cycloid rotor type oil pump directly driven by the crankshaft is used.
This oil pump has used an internal relief method which circulates relief oil to the suction passage in the
oil pump. This aims to minimize oil level change in the oil pan, reduce friction, and reduce air mixing rate
in the oil.
3. Oil Jet
Oil jets for cooling and lubricating the pistons have been provided in the cylinder block, in the center of
the right and left banks.
These oil jets contain a check valve to prevent oil from being fed when the oil pressure is low. This prevents
the overall oil pressure in the engine from dropping.

PREPARATION – 2AZ-FE ENGINE MECHANICALPP–7
PP
EQUIPMENT
V-block -
Piston ring compressor -
Piston ring expander -
Valve seat cutter -
Feeler gauge -
CO/HC meter -
Connecting rod aligner -
Cylinder gauge -
Micrometer -
Precision straight edge -
Radiator cap tester -
Steel square -
Tachometer -
Torque wrench -
Vernier calipers -
Dial indicator with magnetic base -
Alignment tester -
toe-in gauge -
Spring tension gauge -
Slide calipers -
Sandpaper (#400) -
Piston heater -
Wooden block -
Plastigage -
Angle gauge -
Timing light -