2001 TOYOTA PRIUS Service Repair Manual

ENGINE ± 1NZ-FXE ENGINE
171EG07
182EG07
Crankshaft Position
Sensor RotorOil HolePin
No.5 Journal
Balance Weight
No.1 Journal 48
4. Connecting Rod

The connecting rods are made of high-strength
material for weight reduction.

The connecting rod cap is held by bolts tight-
ened to plastic region.
5. Crankshaft

The crankshaft has 5 journals and 4 balance weights.

A crankshaft position sensor rotor has been pressed into the crankshaft to realize an integrated configura-
tion.

The surface roughness of the pins and journals have been improved for low-friction operation.

The bearing width has been reduced for low-friction operation.

ENGINE ± 1NZ-FXE ENGINE
171EG09
VVT-i ControllerTiming ChainExhaust Camshaft
Intake Camshaft
Chain Guide Chain Tension ArmChain Tensioner
171EG10
Exhaust Camshaft
Timing Rotor
Intake Camshaft
VVT-i Controller49
VALVE MECHANISM
1. General
Each cylinder has 2 intake valves and 2 exhaust valves.
The valves are directly opened and closed by 2 camshafts.
The intake and exhaust camshafts are driven by a roller timing chain.
The VVT-i system is used to improve fuel economy, engine performance and reduce exhaust emission.
2. Camshafts
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 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.
The timing rotor is provided behind the intake camshaft to trigger the camshaft position sensor.

ENGINE ± 1NZ-FXE ENGINE
165EG12
Camshaft
Valve Lifter
Valve
171EG12
Camshaft Sprockets
Timing
Chain
Chain Guide
Oil Jet
Crankshaft
Sprocket Chain
Tensioner
Chain
Tension
Arm 50
3. Intake and Exhaust Valve and Valve Lifter
Valve lifters with shimless valve adjustment have been adopted for weight reduction.
The adjustment of the valve clearance is accomplished by selecting and replacing the appropriate valve
lifters.
Narrower valve stems have been adopted to reduce the intake and exhaust resistance and for weight reduc-
tion.

Specifications  mm (in.)
Item
Intake ValveExhaust Valve
Face Diameter30.5 (1.2)25.5 (1.0)
Stem Diameter5.0 (0.20)5.0 (0.20)
4. Timing Chain
A roller timing chain with an 8.0 mm pitch has
been adopted to make the engine more compact
and reduce chain noise.
A material which has excellent wear resistance
has been selected for the timing chain to im-
prove reliability.
The timing chain is lubricated by engine oil
from an oil jet.
Chain tensioner, chain tension arm and chain
guide are established to reduce the engine noise
and friction loss.

ENGINE ± 1NZ-FXE ENGINE
171EG13
Spring
Plunger
Cam
Cam Spring Check Ball
171EG32171EG31
Service Hole for
Chain Tensioner
Oil Pump
Front ViewBack View51
5. Chain Tensioner
The chain tensioner uses a spring and oil pres-
sure to maintain proper chain tension at all
times.
The chain tensioner suppresses noise generated
by the chain.
A ratchet type half-back mechanism is used.
6. Timing Chain Cover
A single-piece, aluminum die-cast timing chain cover that entirely seals the front portion of the cylinder
block and the cylinder head has been adopted.
A service hole for the chain tensioner has been provided in the timing chain cover to improve serviceabili-
ty.

ENGINE ± 1NZ-FXE ENGINE
182EG08
182EG09
MAIN OIL HOLE
RELIEF
VA LV E
RELIEF
VA LV E
OIL FILTER
OIL PUMP
OIL STRAINER
CRANKSHAFT
JOURNAL
CONNECTING
RODOIL JET
PISTON OIL JET
TIMING CHAINCHAIN
TENSIONER
CYLINDER HEAD
CAMSHAFT TIMING
OIL CONTROL VALVE
FILTER
INTAKE
CAMSHAFT
JOURNALEXHAUST
CAMSHAFT
JOURNAL
CAMSHAFT TIMING
OIL CONTROL VALVE
VVT-i
OIL PAN 52
LUBRICATION SYSTEM

The lubrication circuit is fully pressurized and all oil passes through an oil filter.

A trochoid gear type oil pump, which is driven directly by the crankshaft, has been provided in the front
of the cylinder block.

The oil filter has been installed diagonally downward from the side of the cylinder block to improve ser-
viceability.