1995 RENAULT MEGANE SCENIC check engine

PUMP
Mechanical power assisted steering pump
13
CHECKING THE OIL PRESSURE
SPECIAL TOOLING REQUIRED
Mot. 453-01 Hose clamp pliers
Dir. 1204 Pressure test union
Dir. 803 Metric thread union
Fre. 1085
or Pressure gauge
Fre. 244-03
Fre. 284-06 Connecting pipe
Fit clamp Mot. 453-01 to the low pressure pump
hose.
Disconnect the high pressure pipe (take
precautions to catch the oil which will run out).
Insert union Dir. 803 (metric thread) between the
pipe and the pump.
For engines where it is fitted, remove the
pressostat on the rigid pipe (high pressure).
Connect the pressure test union
Dir. 1204 and the oil pressure gauge
Fre. 1085 (or Fre. 244-03 + Fre. 284-06).
77840R1
Connect pressure gauge Fre. 1085 (or Fre. 244-03
+ Fre. 284-06).
Remove clamp Mot. 453-01.
Top up the pump level and run the engine to
check the pressure.
Wheels in straight line:
Regardless of engine speed, the pressure should
not exceed 5 to 7 bars.
Full lock to one side:
Hold the steering at full lock, the maximum
pressure should be 79 to 86 bars.
This operation should not be prolonged to avoid a
high increase in the oil temperature.
Remove union Dir. 803 and pressure gauge
Fre. 1085 or Fre. 244-03 , cutting the supply to the
pump with clamp Mot. 453-01.
Reconnect the high pressure pipe and remove
clamp Mot. 453-01.
Top up the oil in the reservoir.
13-46

ANTIPOLLUTION
Fuel vapour recirculation
14
CHECKING THE OPERATION OF THE CANISTER
BLEED VALVE
A malfunction in the system could cause the idle
speed to be unstable or the engine to stall.
Check the circuit conforms (see diagrams).
Take care to check that the pipe marked "CAN"
on the solenoid valve is connected to the canister.
Check the condition of the pipes up to the fuel
tank.
97393R4
1Inlet manifold
2Canister bleed solenoid valve
3Canister
4Fuel tankAt idle speed, check by connecting a pressure
gauge (- 3 ; +3 bars) (Mot. 1311-01) to the "CAN"
outlet on the solenoid valve, that there is no
vacuum (in the same manner, check the command
value read by the
XR25 using #23 remains at a
minimum X = 0.7 % for F3R and K7M engines). Is
there a vacuum ?
YESIgnition off, use a vacuum pump to apply a
vacuum of 500 mbars to the solenoid valve
at (C). The vacuum should not vary by more
than 10 mbars in 30 seconds.
Does the pressure vary?
YESThe solenoid valve is faulty, renew
it. Air must also be blown into the
pipe connecting the solenoid valve
to the canister to eliminate any
particles of active carbon.
NOThere is an electrical fault - check
the circuit.
NOUnder bleeding conditions (engine not at
idle speed, engine warm), there should be
an increase in the vacuum (at the same
time, the value for #23 on the XR25 should
increase forF3R and K7M engines).
The fuel tank breather pipe can also be checked.
After removing the filler cap, use a vacuum pump
to apply a vacuum to the pipe at (B). If a vacuum
can be applied to the pipe this shows that the
overfilling valve is correctly sealed.
As soon as the filler cap is replaced, however, the
vacuum should disappear quickly as the pipe is no
longer blocked and the internal degassing
chambers in the fuel tank are connected.
14-8

ANTIPOLLUTION
Oil vapour rebreathing
14
E7J engine
PRESENTATION OF THE CIRCUIT
94563R3
Upstream rebreathing circuit
1Take-off on air filter
2Filter - nozzle connecting pipe
3 6 mm diameter nozzle
Downstream rebreathing circuit
4 1.5 mm diameter nozzle
5Restriction to T union connecting pipe
6T union
7Take-off on inlet manifold
8To canister bleed
CHECKING
To guarantee correct operation of the
antipollution system, the oil vapour rebreathing
circuit should be kept clean and in good
condition.
Check the nozzles are present and correct.
14-9

99231R
ANTIPOLLUTION
Oil vapour rebreathing
14
K7M engine
PRESENTATION OF THE CIRCUIT
1Cylinder head
2Manifold
3Oil vapour rebreathing pipe connected upstream of the throttle body (the circuit is used for average and
high loads)
4Oil vapour rebreathing pipe connected downstream of the throttle body
5Fuel vapour recirculation pipe
6T piece connecting the oil vapour rebreathing pipe (4) and fuel vapour recirculation pipe (5)
7Oil vapour rebreathing pipe and fuel vapour recirculation pipe
8Air duct
95 mm diameter nozzle
CHECKING
To guarantee correct operation of the antipollution system, the oil vapour rebreathing circuit should be kept
clean and in good condition.
Check the nozzle is present and correct.
14-10

DI1407-1
ANTIPOLLUTION
Oil vapour rebreathing
14
F3R engine
PRESENTATION OF THE CIRCUIT
1Inlet manifold
2Throttle body
3Oil vapour rebreathing pipe (connected to throttle body)
4Oil decanter
5Oil vapour rebreathing pipe from the engine to the decanter
The restrictions upstream and downstream of the oil vapour rebreathing system are moulded into the
throttle body.
CHECKING
To guarantee correct operation of the antipollution system, the oil vapour rebreathing circuit should be kept
clean and in good condition.
14-11

ANTIPOLLUTION
Exhaust gas recirculation (EGR)
14
K7M engine
OPERATING CONDITIONS FOR THE EGR SOLENOID
VALVE
The EGR system is operational if the following
conditions are met:
• coolant temperature greater than 20°C,
• air temperature greater than 5°C,
• no load position not recognised and throttle
position less than a set threshold, dependent
on engine speed (at 1024 rpm the throttle
position must be greater than 59 seen
using # 17 ;
at 5120 rpm the throttle position must be
greater than 103 seen using # 17),
• manifold vacuum greater than a certain
threshold.
The EGR solenoid valve is not operated if a fault is
detected with the :
- air temperature sensor,
- manifold pressure sensor,
- throttle potentiometer,
- EGR system.
A status bargraph on the XR25 visualises
operation of the EGR solenoid valve by the
computer.
It is however better to carry out a road test to
show this status. A test with the vehicle stationary,
engine operating under low loads is not
sufficient.
A faulty component in the EGR system will cause
an obvious worsening of the exhaust gas values.
CHECKING THE SEALING AND OPERATION OF THE
EGR SOLENOID VALVE
After the cooling fan has operated at least once,
stop the engine and turn the ignition off.
Disconnect the electrical connector.
Supply a 12 V feed directly to the solenoid valve.
Disconnect the pipe (D) connected to the vacuum
reservoir from the solenoid valve. In its place
connect a vacuum pump.
Create a vacuum of 300 mbars. The pressure
should not drop by more than 2 mbars per second
(120 mbars per minute).
Eliminate the vacuum to return the solenoid valve
to atmospheric pressure.
Run the engine at idle speed.
Create a vacuum of 300 mbars again, the engine
should run at idle speed, but unsteadily. If this is
not the case, replace the solenoid valve assembly.
Erase the computer memory after the operation.
14-16

ANTIPOLLUTION
Catalytic converter
14
To meet the requirements of the EURO 96
standard, this vehicle is fitted with an oxidation
catalytic converter.
ROLE
The converter deals with the following three
pollutants at the same time:
- hydrocarbons (HC),
- carbon monoxide (CO),
- particulates, by a chemical oxidation reaction.
FUEL
No specific fuel is required for correct operation.
CONSTITUTION
The converter comprises:
- a monolith (1) in a honeycomb ceramic. A
substance containing precious metals is
deposited on the walls of the honeycomb
(mainly platinum),
- a metal jacket (2) retaining the monolith in its
shell,
- a shell (3) with inlet and outlet cones,
optimising the distribution of exhaust gas
flow.
99781R
CHECKING THE CATALYTIC CONVERTER
The performance of the catalytic converter on the
exhaust gas is difficult to check. The maximum
temperature of the exhaust gas from a diesel
engine is not sufficient to melt the monolith (in
comparison to petrol engines).
Diesel engine
14-19

ANTIPOLLUTION
Catalytic converter - oxygen sensor
14
CHECKS TO BE MADE BEFORE THE ANTI-
POLLUTION TEST
Ensure:
- the ignition system is operating correctly
(correct spark plugs, correctly set plug gap,
high voltage leads in good condition and
correctly connected).
- the injection system is operating correctly
(supply is correct - check using the XR25).
- the exhaust pipe is correct and is sealed.
- the EGR is operating correctly.
Check the vehicle history if possible (run out of
fuel, lack of power, use of incorrect fuel).
CHECKING ANTI-POLLUTION STANDARDS
Run the engine until the engine cooling fan has
operated twice.
Connect a correctly calibrated four gas analyser to
the exhaust tail pipe.
Keep the engine speed at 2500 rpm for
approximately 30 seconds then let the engine
return to idle speed and note the pollutant values.
CO
≤0.3 %
CO
2≥14.5 %
HC
≤100 ppm
0,97
≤λ≤1.03
1
NOTE : λ = ————
richness
λ>1→lean mixture
λ<1→rich mixture
If, after these tests, the values are correct, the
antipollution system is correct.
If the values are not correct, additional tests must
be carried out:
- Check the condition of the engine (condition
of the oil, valve clearances, timing, etc,...),
- Check the correct operation of the oxygen
sensor (see section 17) ,
- test for the presence of lead (see following
page).
If the test for the presence of lead is positive, en-
sure the vehicle uses two or three full tanks of un-
leaded fuel before replacing the oxygen sensor.
If, after all these tests have been carried out, the
values still do not conform, the catalytic converter
must be replaced. Petrol engine
14-21