engine overheat PORSCHE 911 2009 5.G Owners Manual

218
Maintenance, Car Care
Emission Control SystemIn the interest of clean air Pollution of our environment has become a prob-
lem that is of increasing concern to all of us. We
urge you to join us in our efforts for cleaner air in
controlling the pollutants emitted from the auto-
mobile.
Porsche has developed an emission control sys-
tem that controls or reduces those parts of the
emission that can be harmful to our environment.
Your Porsche is equipped with such a system.
Porsche warrants the Emission Control System in
your new car under the terms and conditions set
forth in the Warranty Booklet.
You, as the owner of the vehicle, have the
responsibility to provide regular maintenance serv-
ice for the vehicle and to keep a record of all main-
tenance work performed. To facilitate record
keeping, have the service performed by author-
ized Porsche dealers. They have Porsche trained
technicians and special tools to provide fast and
efficient service. To assure efficient operation of the Emission
Control System:
fHave your vehicle maintained properly and in
accordance with the recommendations de-
scribed in your Maintenance Booklet.
Lack of proper maintenance, as well as im-
proper use of the vehicle, will impair the func-
tion of the emission control system and could
lead to damage.
fDo not alter or remove any component of the
emission control system.
fDo not alter or remove any device, such as
heat shields, switches, ignition wires, valves,
etc., which are designed to protect your vehi-
cle’s emission control system.
In addition to serious engine damage, this can
result in a fire if excess raw fuel reaches the
exhaust system.
fDo not continue to operate your vehicle if you
detect engine misfire or other unusual operat-
ing conditions.
Parking
Warning!
Danger of fire resulting in serious personal
injury or death.
fDo not park or operate the vehicle in areas
where the hot exhaust system may come in
contact with dry grass, brush, fuel spill or oth-
er flammable material.
fIf your car catches on fire for any reason, call
the fire department.
Do not endanger your life by attempting to put out the fire.
Undercoating
Danger!
Danger of fire resulting in serious personal
injury or death.
fDo not apply additional undercoating or rust-
proofing on or near the exhaust manifold,
exhaust pipes, catalytic converters or heat
shields. During driving the substance used for undercoating could overheat and ignite.

Maintenance, Car Care
219
How Emission Control Works When an automobile engine is running, it uses en-
ergy generated through the combustion of a mix-
ture of air and fuel. Depending on whether a car is
driven fast or slowly or whether the engine is cold
or hot, some of the fuel (hydrocarbons) may not
be burned completely, but may be discharged into
the engine crankcase or exhaust system. Additon-
al hydrocarbons may enter the atmosphere
through evaporation of fuel from the fuel tank.
These hydrocarbons (HC), when released into the
air, contribute to undesirable pollution.
In addition, carbon monoxide (CO) and oxides of
nitrogen (NOx) contribute to engine emissions.
They, too, are formed during the combustion proc-
ess and discharged into the exhaust system.
To reduce these pollutants, your Porsche is
equipped with a precisely calibrated fuel injection
system to assure a finely balanced air/fuel mixture
under all operating conditions.
Oxygen sensor The oxygen sensor, installed in the exhaust pipe
continuously senses the oxygen content of the
exhaust and signals the information to an electron-
ic control unit. The control unit corrects the air/
fuel ratio, so the engine always receives an accu-
rately metered air/fuel mixture. Crankcase ventilation Through crankcase ventilation, undesirable emis-
sions from the engine crankcase are not permit-
ted to reach the outside atmosphere. These emis-
sions are recirculated from the crankcase to the
air intake system. From here the emissions mix
with the intake air and are later burned in the en-
gine. Catalytic converters The catalytic converters are efficient “clean-up”
devices built into the exhaust system of the vehi-
cle. The catalytic converters burn the undesirable
pollutants in the exhaust gas before it is released
into the atmosphere.
The exclusive use of unleaded fuel is critical-
ly important for the life of the catalytic con-
verters. Therefore, only unleaded fuel must
be used.The catalytic converters will be damaged by:
– push or tow starting the vehicle
– misfiring of the engine
– turning off the ignition while the vehicle is mov-
ing or
– driving until the fuel tank is completely empty
– by other unusual operating conditions.
fDo not continue to operate your vehicle under
these conditions, since raw fuel might reach
the catalytic converters. This could result in
overheating of the converters. Federal law pro-
hibits use of leaded fuel in this car.