3
CAMRY ± NEW FEATURES33
5S-FE ENGINE
1. Description
The intake and exhaust systems have been changed to increase torque and reduce noise. On the California
specification model, the air assist system has been discontinued.
Engine Specifications
ItemNewPrevious
No. of Cyls. & Arrangement4-Cylinder, In-Line
Valve Mechanism16-Valve DOHC,
Belt & Gear Drive
Combustion CamberPentroof Type
ManifoldsCross-Flow
Fuel SystemSFI
Displacement cm3 (cu. in.)2164 (132.0)
Bore x Stroke mm (in.)87.0 x 91.0 (3.43 x 3.58)
Compression Ratio9.5 : 1
Max. Output [SAE-NET]
101 kW @ 5200 rpm
(136 HP @ 5200 rpm)
99 kW @ 5200 rpm*
(133 HP @ 5200 rpm)*99 kW @ 5200 rpm
(133 HP @ 5200 rpm)
97 kW @ 5200 rpm*
(130 HP @ 5200 rpm)*
Max. Torque [SAE-NET]
203 N.m @ 4400 rpm
(150 ft-lbf @ 4400 rpm)
201 N
.m @ 4400 rpm*
(148 ft-lbf @ 4400 rpm)*
199 N.m @ 4400 rpm
(147 ft
.lbf @ 4400 rpm)
197 N
.m @ 4400 rpm*
(145 ft
.lbf @ 4400 rpm)*
IntakeOpen3 BTDC
Valve
IntakeClose43 ABDCValve
Timing
ExhaustOpen45 BBDCg
ExhaustClose3 AT D C
Fuel Octane Number RON91
Oil GradeAPI SJ EC-II, ILSAC or Better
*: California Specification Models
CAMRY ± NEW FEATURES36
5S-FNE ENGINE
1. Description
The 5S-FNE engine is a new engine that uses CNG (Compressed Natural Gas) as fuel, which has been devel-
oped based on the 5S-FE gasoline engine.
The main component of natural gas is methane (CH
4), which has fewer carbous (C) than gasoline (mean mo-
lecular formula: C
7.5H13.4). Therefore, the amount of CO2 discharged by this engine is approximately 70%
that of the gasoline engine. Furthermore, this engine achieves low-emission operation by precisely controlled
air-fuel ratio and using special catalysts for the CNG application.
However, because the fuel is in the gaseous form, its volumetric efficiency is low, causing lower power output
if this fuel is used in the base engine.
Therefore, the 5S-FNE engine has adopted the following features: a high compression ratio, the intake valves
with early closed timing, the intake and exhaust valves with increased lift, a low back pressure muffler made
possible by the 2-way exhaust system, injectors for gaseous fuel, and a catalytic converter designed exclu-
sively for CNG application. At the same time, precision air-fuel ratio control is effected through the use of
the air-fuel ratio sensor* and the heater oxygen sensor, thus achieving the level of performance that is equiva-
lent to the base engine. Moreover, this engine realizes extremely low emissions and restoring engine torque.
*: Already adopted on the California specification 5S-FE engine.
Specifications
Item5S-FNE Engine5S-FE Engine
No. of Cyls. & Arrangement4-Cylinder, In-Line
Valve Mechanism16-Valve DOHC,
Belt & Gear Drive
Combustion CamberPentroof Type
ManifoldsCross-Flow
Fuel SystemSFI
Displacement cm3 (cu.in.)2164 (312.0)
Bore x Stroke mm (in.)87.0 x 91.0 (3.43 x 3.58)
Compression Ratio11.0 : 19.5 : 1
Max. Output [SAE-NET]88 kW @ 5200 rpm
(118 HP @ 5200 rpm)
101 kW @ 5200 rpm
(136 HP @ 5200 rpm)
97 kW @ 5200 rpm*
(133 HP @ 5200 rpm)*
Max. Torque [SAE-NET]178 N.m @ 2400 rpm
(131 ft-lbf @ 2400 rpm)
203 N.m @ 4400 rpm
(150 ft-lbf @ 4400 rpm)
201 N
.m @ 4400 rpm*
(148 ft-lbf @ 4400 rpm)*
IntakeOpen3 BTDC
Valve
IntakeClose38 ABDC43 ABDCValve
Timing
ExhaustOpen45 BBDCExhaustClose3 AT D C
Fuel Octane Number RON13091
Oil GradeAPI SJ EC or ILSAC
*: California Specification Models
3
CAMRY ± NEW FEATURES
167CN05
WU-TWC
167CN06
TWCSub MufflerMain Muffler41
5. Intake and Exhaust System
Throttle Body
The throttle body is basically the same as that of the 5S-FE engine. However, to ensure the starting perfor-
mance at low temperatures, the air passage for the IAC (Idle Air Control) has been increased on the 5S-FNE
engine. The IAC valve is a 1-coil type with a built-in driver.
Exhaust Manifold
As in the California specification 5S-FE engine,
the stainless steel exhaust manifold and WU-
TWC (Warm Up Three-Way Catalytic Convert-
er) have been integrated to improve the warm-up
performance of TWC, thus reducing exhaust
emissions.
However, the 5S-FNE engine uses a catalytic
converter that has been designed exclusively for
the CNG application, in which the loading of the
noble metal has been increased.
Exhaust Pipe
1) General
To secure sufficient luggage compartment capacity, the main muffler has been relocated below the rear
seat. Furthermore, the muffler capacity has been increased.
A 2-way exhaust control system has been adopted to improve engine performance and reduce the exhaust
noise.
Similar to the WU-TWC, the TWC (Three-Way Catalytic Converter) has been designed exclusively for
the CNG application, in which the loading of the noble metal has been increased.
3
CAMRY ± NEW FEATURES49
8. Engine Control System
General
An engine control system based on the 5S-FE engine has been adopted. The knock sensor has been discon-
tinued because natural gas has a high octane value and is less susceptible to knocking.
The engine control system of 5S-FNE and 5S-FE engines are compared below.
System
Outline5S-FNE5S-FE
SFI
Se
quential
A D-type SFI system is used, which indirectly detects
intake air volume by manifold absolute pressure sensor.Sequential
Multiport Fuel
InjectionThe fuel injection system is a sequential multiport fuel
injection system.
Ignition timing is determined by the ECM based on
signals from various sensors.
ESA
Electronic Spark
AdvanceThe ECM corrects the ignition timing in response to
engine knocking in accordance with the signals
received from the knock sensor.
Ð
dva ce
Torque control correction during gear shifting had been
used to minimize the shift shock.*1
IAC
(Idle Air Control)A rotary solenoid type IAC valve controls the fast idle
and idle speeds.(1-Coil Type
Built-in Driver)(2-Coil Type)
Fuel Pump ControlFuel pump operation is controlled by signal from the
ECM.Ð
Fuel Cut-Off
Control
The fuel shutoff valves for the fuel tank, fuel pressure
regulator, and delivery pipe are shut off to stop the
supply of fuel when the ignition switch is turned OFF or
during abnormal conditions (such as engine stalling,
SRS airbag deployed, etc.).
Ð
Injector ControlPrevents the frozen stuck of the injector to ensure the
startability of the engine at low temperature.Ð
Oxygen Sensor
and Air Fuel Ratio
Sensor
Heater ControlMaintains the temperature of the oxygen sensor and air
fuel ratio sensor at an appropriate level to increase
accuracy of detection of the oxygen concentration in the
exhaust gas.
*2
EGR Cut-Off
ControlCuts off EGR according to the engine condition to
maintain drivability of the vehicle and durability of the
EGR components.
Evaporative
Emission ControlThe ECM controls the purge flow of evaporative
emissions (HC) in the charcoal canister in accordance
with engine conditions.
Ð
Air Conditioning
Cut-Off ControlBy turning the air conditioning compressor ON or OFF
in accordance with the engine condition, drivability is
maintained.
*3*3
Diagnosis
When the ECM detects a malfunction, the ECM
diagnoses and memorized the failed section.
DiagnosisThe diagnosis system includes a function that detects a
malfunction in the evaporative emission control system.Ð
Fail-Safe
When the ECM detects a malfunction, the ECM stops or
controls the engine according to the data already stored
in memory.
*1: Only for Automatic Transaxle Model
*
2: Air fuel ratio sensor only for California specification model
*
3: The air conditioning magnet clutch controled by the ECM
The 5S±FE engine is an in±line, 4±cylinder engine with the cylinders numbered 1±2±3±4
from the front. The crankshaft is supported by five bearings inside the crankcase. These bearings
are made of aluminum alloy.
The crankshaft is integrated with eight weights for balance. Oil holes are placed in the center of
the crankshaft to supply oil to the connecting rods, bearing, pistons and other components.
The firing order is 1±3±4±2. The cylinder head is made of aluminum alloy, with a cross flow
type intake and exhaust layout and with pent±roof type combustion chambers. The spark plugs
are located in the center of the combustion chambers.
The intake manifold has four independent long ports and utilizes the inertial supercharging effect
to improve engine torque at low and medium speeds.
Exhaust and intake valves are equipped with irregular pitch springs made of special valve spring
carbon steel which are capable of functioning no matter what the engine speed.
The intake camshaft is driven by a timing belt, and a gear on the intake camshaft engages with
a gear on the exhaust camshaft to drive it. The cam journal is supported at five places between
the valve lifters of each cylinder and on the front end of the cylinder head. Lubrication of the cam
journals and gears is accomplished by oil being supplied through the oiler port in the center of the
camshaft.
Adjustment of the valve clearance is done by means of an outer shim type system, in which valve
adjusting shims are located above the valve lifters. This permits replacement of the shims without
removal of the camshafts.
Pistons are made of high temperature±resistant aluminum alloy, and a depression is built into
the piston head to prevent interference with the valves.
Piston pins are the full±floating type, with the pins fastened to neither the piston boss nor the
connecting rods. Instead, snap rings are fitted on both ends of the pins, preventing the pins from
falling out.
The No.1 compression ring is made of steel and the No.2 compression ring is made of cast iron.
The oil ring is made of a combination of steel and stainless steel. The outer diameter of each
piston ring is slightly larger than the diameter of the piston and the flexibility of the rings allows
them to hug the cylinder walls when they are mounted on the piston. Compression rings No.1 and
No.2 work to prevent gas leakage from the cylinder and the oil ring works to scrape oil off the
cylinder walls to prevent it from entering the combustion chambers.
The cylinder block is made of cast iron. It has four cylinders which are approximately twice the
length of the piston stroke. The top of each cylinder is closed off by the cylinder head and the
lower end of the cylinders becomes the crankcase, in which the crankshaft is installed. In
addition, the cylinder block contains a water jacket, through which coolant is pumped to cool the
cylinders.
The oil pan is bolted onto the bottom of the cylinder block. The oil pan is an oil reservoir made of
pressed sheet steel. A dividing plate is included 'inside the oil pan to keep sufficient oil in the
bottom of the pan even when the vehicle is tilted. This dividing plate also prevents the oil from
making waves when the vehicle is stopped suddenly and the oil shifts away from the oil pump
suction pipe.
The 5S±FE engine uses two balance shafts. The balance shafts are fitted in balance shaft
housings that are located at the bottom of the cylinder block. The No. 1 balance shaft is driven by
the drive gear of the crankshaft No.3 counterweight at twice the speed of the crankshaft. The No.
2 balance shaft is driven by the No±1 balance shaft at the same speed in the same direction as the
crankshaft. The balance shafts are designed to eliminate secondary inertia force from the engine,
thereby reducing the engine noise (booming noise).
± 5S±FE ENGINEENGINE MECHANICALEG1±3
FUEL SYSTEM
1. When disconnecting the high pressure fuel line, a
large amount of gasoline will spill out, so observe the
following procedures:
(a) Put a container under the connection.
(b) Slowly loosen the connection.
(c) Disconnect the connection.
(d) Plug the connection with a rubber plug.
2. When connecting the flare nut or union bolt on the
high pressure pipe union, observe the following proce±
dures:
Union Bolt Type:
(a) Always use a new gasket.
(b) Tighten the union bolt by hand.
(c) Tighten the union bolt to the specified torque.
Torque: 29 N±m (300 kgf±cm, 22 ft±lbf)
Flare Nut Type:
(s) Apply alight coat of engine oil to the flare and tighten
the flare nut by hand.
(b) Using SST, torque the flare nut.
SST 09631±22020
Torque:
28 N±m (285 kgf±cm, 21 ft±lbf) for fuel pump side
30 N±m (310 kgf±cm, 22 ft±lbf) for others
HINT: Use a torque wrench with a fulcrum length of
30 cm (11.81 in.).
3. Observe the following precautions when removing
and installing the injectors.
(a) Never reuse the O±ring.
(b) When placing a new O±ring on the injector, take care
not to damage it in any way.
(c) Coat a new 0± ring with spindle oil or gasoline before
installing±never use engine, gear or brake oil.
4. Install the injector to delivery pipe and intake manifold
as shown in the illustration.
± 5S±FE ENGINEMFI/SFI SYSTEMEG1±175
RADIATOR
The radiator performs the function of cooling the coolant which has passed through the water
jacket and become hot, and it is mounted in the front of the vehicle. The radiator consists of an
upper tank and lower tank, and a core which connects the two tanks. The upper tank contains the
inlet for coolant from the water jacket and the filler inlet. It also has a hose attached through
which excess coolant or steam can flow. The lower tank has an outlet and drain cock for the
coolant. The core contains many tubes through which coolant flows from the upper tank to the
lower tank as well as to cooling fins which radiate heat away from the coolant in the tubes. The
air sucked through the radiator by the electric fan, as well as the wind generated by the vehicle's
travel, passes through the radiator, cooling the coolant. Models with automatic transmission
include an automatic transmission fluid cooler built into the lower tank of the radiator. A fan with
an electric motor is mounted behind the radiator to assist the flow of air through the radiator. The
fan operates when the engine coolant temperature becomes high in order to prevent it from be-
coming too high.
RADIATOR CAP
The radiator cap is a pressure type cap which seals the radiator, resulting in pressurization of the
radiator as the coolant expands. The pressurization prevents the coolant from boiling even when
the engine coolant temperature exceeds 100°C (212°F). A relief valve (pressurization valve) and a
vacuum valve (negative pressure valve) are built into the radiator cap. The relief valve opens and
lets steam escape through the overflow pipe when the pressure generated inside the cooling sys-
tem exceeds the limit (coolant temperature: 110±120°C (230±248°F), pressure; 58.8103.0 kpa
(0.6±1.05 kgf/cm
2, 8.5±14.9 psi). The vacuum valve opens to alleviate the vacuum which develops
in the cooling system after the engine is stopped and the engine coolant temperature drops. The
valve's opening allows the coolant in the reservoir tank to return to the cooling system.
RESERVOIR TANK
The reservoir tank is used to catch coolant which overflows from the cooling system as a result
of volumetric expansion when the coolant is heated. The coolant in the reservoir tank returns to
the radiator when the coolant temperature drops, thus keeping the radiator full at all times and
avoiding needless coolant loss.
Check the reservoir tank level to learn if the coolant needs to be replenished.
WATER PUMP
The water pump is used for forced circulation of coolant through the cooling system. It is
mounted on the front of the cylinder block and driven by a timing belt.
THERMOSTAT
The thermostat has a wax type bypass valve and is mounted in the water inlet housing. The
thermostat includes a type of automatic valve operated by fluctuations in the engine coolant
temperature. This valve closes when the engine coolant temperature drops, preventing the
circulation of coolant through the engine and thus permitting the engine to warm up rapidly. The
valve opens when the engine coolant temperature has risen, allowing the circulation of coolant.
Wax inside the thermostat expands when heated and contracts when cooled. Heating the wax
thus generates pressure which overpowers the force of the spring which keeps the valve closed,
thus opening the valve. When the wax cools, its contraction allows the force of the spring to take
effect once more, closing the valve. The thermostat in this engine operates at a temperature of
82C (180F).
± 5S±FE ENGINECOOLING SYSTEMEG1±239
2. CHECK ENGINE COOLANT QUALITY
There should not be any excessive deposits of rust or
scales around the radiator cap or radiator filler hole,
and the engine coolant should be free from oil.
If excessively dirty, replace the engine coolant.
3. REPLACE ENGINE COOLANT
(a) Remove the radiator cap.
CAUTION: To avoid the danger of being burned, do not
remove It while the engine and radiator are still hot, as
fluid and steam can be blown out under pressure.
(b) Drain the engine coolant from the radiator drain cock
and engine drain plug. (Engine drain plug at the right
rear of cylinder block.)
(c) Close the drain cock and plug.
Torque (Engine drain plug):
13 N±m (130 kgf±cm, 9 ft±lbf)
(d) Slowly fill the system with coolant.
Use a good brand of ethylene±glycol base
coolant and mix it according to the
manufacturer 's directions.
Using engine coolant which includes more than
5096 ethylene±glycol (but not more than 7096) is
recommended.
NOTICE:
wDo not use a alcohol type coolant.
wThe engine coolant should be mixed with demineral±
ized water or distilled water.
Capacity (w/ Heater):
8.3 liters (6.7 US qts, 5.5 Imp.qts)
(a) Reinstall the radiator cap.
(f) Warm up the engine and check for leaks.
(g) Recheck the engine coolant level and refill as neces±
sary.
COOLANT CHECK AND
REPLACEMENT
1. CHECK ENGINE COOLANT LEVEL AT RESERVOIR
TANK
The engine coolant level should be between the
ºLOWº and ªFULLº lines.
If low, check for leaks and add engine coolant up to
the ªFULLº line.
± 5S±FE ENGINECOOLING SYSTEMEG1±241