2000 TOYOTA CAMRY low oil pressure

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
172CM14
Fuel
Pressure
SensorFuel Temp.
SensorFuel
Pressure
RegulatorFuel Shutoff ValveFuel Tank
Fuel Shutoff ValveRelief Valve
Inlet Check
Valve
Fuel Temp.
Sensor
Coupler
Tank Valve Assembly
Vent Tube Manual
Shutoff
Valve Oil
Separator
Fuel Shutoff Valve Injectors
Delivery Pipe Discharge
ValveFuel
Pressure
SensorFuel
Filter43
6. Fuel System
General
The compressed gas [maximum pressure approximately 250 kg / cm
2 (3600 psi, 24.8 MPa) @ 21C
(70F)] from the CNG fuel tank located in the rear section of the vehicle is routed via a fuel filter to the
engine compartment. The pressure of the fuel is then reduced to 8 kg / cm
2 (114 psi, 785 kPa).
A pressure regulator and injectors designed exclusively for CNG application have been adopted.
A fuel pressure sensor and a fuel temperature sensor that are used for the correction of the fuel injection
volume are located on the delivery pipe.
The fuel tank, pressure regulator, and the delivery pipe are provided with shutoff valves that shut off the
fuel when the ignition switch is turned OFF.
In addition, these valves shut off the fuel when the engine stalls, the SRS airbag is deployed, or the pres-
sure in the main pipe becomes abnormally low.
A fuel temperature sensor for the fuel gauge is mounted on the tank valve assembly, and a fuel pressure
sensor is mounted immediately upstream of the pressure regulator.

Fuel System Diagram 

CAMRY ± NEW FEATURES
167CN10
172CM15
Fuel
Shutoff
Valve
Water Passage
Oil SeparatorRelief Valve 46
Fuel Filter
Mounted below the vehicle floor, the fuel filter
removes any moisture or oil from the fuel.
Fuel Pressure Regulator
The fuel pressure regulator regulates the fuel pressure by reducing the pressure of the compressed natural
gas from the fuel tank to the fuel injection pressure, which is 8 kg / cm
2 (114 psi, 785 kPa).
Similar to the fuel shutoff valve for the fuel tank, a fuel shutoff valve is provided on the fuel inlet side
of the fuel pressure regulator to shut off the supply of fuel when the engine is stopped or during abnormal
conditions.
An oil separator that traps the moisture and oil in the fuel is provided on the low pressure side.
A built-in relief valve is provided to protect the parts located on the low pressure side.
While the fuel pressure is being reduced by the fuel pressure regulator, the Joule-Thomson effect
associated with the expansion of the gas causes the fuel pressure regulator to be cooled excessively, exert-
ing unfavorable influence on the rubber parts such as diaphragms and fuel hoses.
Therefore, to raise the gas temperature, a water passage is provided in the fuel pressure regulator to allow
the engine coolant to warm the regulator.

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

CAMRY ± NEW FEATURES
No.4 INJECTOR
SPARK PLUGSIGNITERS and
IGNITION COILS
No.2 INJECTOR
No.1 INJECTOR
No.3 INJECTOR
SENSORS ACTUATORS
MANIFOLD ABSOLUTE
PRESSURE SENSORSFI PIM#10+
CRANKSHAFT POSITION
SENSORNE
CAMSHAFT POSITION
SENSORG
ENGINE COOLANT TEMP.
SENSORTHW
INTAKE AIR TEMP. SENSORTHA
THROTTLE POSITION SENSORVTA
COMBINATION METER
SPD
Vehicle Speed Signal
AIR FUEL RATIO SENSOR
(Bank 1, Sensor 1)AF
HEATED OXYGEN SENSOR
(Bank 1, Sensor 2)OX2
POWER STEERING OIL
PRESSER SWITCHPSW
TAILLIGHT & REAR WINDOW
DEFOGGER SYSTEMELS
IGNITION SWITCHSTA
PARK / NEUTRAL POSITION
SWITCHNSW
STOP LIGHT SWITCHSTP
AIRBAG SENSOR ASSEMBLY
F/PS
Fuel Cut-Off Signal
#10
#20+
#20
#30+
#30
#40+
#40
ESA
IGT1,
IGT2
IGF
CONTROL VALVEIACRSD
VSV EGREGR
AIR FUEL RATIO SENSOR
HEATER AIR FUEL RATIO SENSOR
HEATER CONTROLHTAF
HEATED OXYGEN SENSOR
HEATER OXYGEN SENSOR HEATER
CONTROLHT2
MAGNET CLUTCH RERAYAIRE CONDITIONING
CUT-OFF CONTROLMGC
FUEL GAGE
LOW FUEL LEVEL WARNING
LIGHT
ECM
AIR CONDITIONING SWITCHA/C SW
R, 2, L
FUEL
FUEL W
50
Construction
The configuration of the engine control system in the 5S-FNE engine is as shown in the following chart.
(Continued)

5. CHECK CYLINDER COMPRESSION PRESSURE
(a) Insert a compression gauge into the spark plug hole.
(b) Fully open the throttle.
(c) While cranking the engine, measure the compression
pressure.
HINT: Always use a fully charged battery to obtain
engine speed of 250 rpm or more.
(d) Repeat steps
(a) through
(c) for each cylinder.
NOTICE: This measurement must be done in as short a
time as possible.
Compression pressure:
1,226 kPa (12.5 kgf/cm
. 178 psi) or more
Minimum pressure:
981 kPa (10.0 kgf/cm
, 142 psi)
Difference between each cylinder:
98 kPa (1.0 kgf/cm
. 14 psi) or less
COMPRESSION CHECK
HINT: If there is lack of power, excessive oil consump±
tion or poor fuel economy, measure the compression
pressure.
1. WARM UP AND STOP ENGINE
Allow the engine to warm up to normal operating
temperature.
2. DISCONNECT DISTRIBUTOR CONNECTOR(S)
3. DISCONNECT HIGH ±TENSION CORDS FROM
SPARK PLUGS
Disconnect the high ± tension cords at the rubber
boot.
DO NOT pull on the cords.
NOTICE: Pulling on or bending the cords may damage the
conductor inside.
4. REMOVE SPARK PLUGS
Using a 16 mm plug wrench, remove the spark plug.
± 5S±FE ENGINEENGINE MECHANICALEG1±23

(e) If the cylinder compression in one or more cylinders is
low, pour a small amount of engine oil into the cylin±
der through the spark plug hole and repeat steps (a)
through
(c) for cylinders with low compression.
wIf adding oil helps the compression, chances are
that the piston rings and/or cylinder bore are
worn or damaged.
wIf pressure stays low, a valve may be sticking or
seating is improper, or there may be leakage past
the gasket.
6. REINSTALL SPARK PLUGS
Using a 16 mm plug wrench, install the spark plug.
Torque: 18 N±m (180 kgf±cm, 13 ft±lbf)
7. RECONNECT HIGH±TENSION CORDS TO SPARK
PLUGS
8. RECONNECT DISTRIBUTOR CONNECTOR(S)
± 5S±FE ENGINEENGINE MECHANICALEG1±24

11. DISCONNECT OIL PRESSURE SWITCH
CONNECTOR
12. DISCONNECT ENGINE WIRE (FOR OXYGEN
SENSORS) FROM ENGINE HANGER
13. REMOVE WATER OUTLET
(a) Disconnect the following connectors:
(1) Engine coolant temperature sender gauge con±
nector
(2) Engine coolant temperature sensor connector
(b) Disconnect the following hoses:
(1) Upper radiator hose
(2) Water bypass pipe hose
(3) Heater water hose
(4) IAC water bypass hose
(5) 2 TVV (for EVAP) vacuum hoses
14. REMOVE WATER BYPASS PIPE
(a) Disconnect the following hoses:
(1) IAC water bypass hose
(2) Heater water hose
(3) w/ Oil Cooler:
2 oil cooler water bypass hoses (5) 3 bolts and 2 nuts
(6) Exhaust manifold
(7) Gasket
(8) Retainer
(9) Cushion
(10) WU±TWC
(c) Remove the 2 bolts, water outlet and gasket.
± 5S±FE ENGINEENGINE MECHANICALEG1±44