engine Seat Leon 5D 2013 Repair Manual

232Driving and the environment
Reduce idling time
In vehicles with the Start-Stop system idling is automatically reduced. In ve-
hicles without the Start-Stop system it is worth switching off the engine, for
example, at level crossings and at traffic lights that remain red for long peri-
ods of time. When an engine has reached operating temperature, and de-
pending on the cylinder capacity, keeping it switched off for a minimum of
about 5 seconds already saves more than the amount of fuel necessary for
restarting.
The engine takes a long time to warm up when it is idling. Mechanical wear
and pollutant emissions are also especially high during this initial warm-up
phase. It is therefore best to drive off immediately after starting the engine.
Avoid running the engine at high speed.
Regular maintenance
Regular servicing helps in saving fuel even before the engine is started. A
well-serviced engine gives you the benefit of improved fuel efficiency as
well as maximum reliability and an enhanced resale value. A badly serviced
engine can consume up to 10% more fuel than necessary.
Avoid short journeys
The engine and catalytic converter need to reach their optimal operating
temperature in order to minimise fuel consumption and emissions.
A cold engine consumes a disproportionate amount of fuel. The engine only
reaches its working temperature after about four kilometres (2.5 miles),
when fuel consumption will return to a normal level.
Check tyre pressure
Always make sure the tyres are inflated to the correct pressures
⇒ page 265 to save fuel. If the pressure is below half bar, fuel consumption
may increase by 5%. Due to the greater rolling resistance, under-inflation
also increases tyre wear and impairs handling.
Do not use winter tyres all year round as they increase fuel consumption by
up to 10%. Avoid carrying unnecessary loads
Given that every kilo of
extra weight will increase the fuel consumption, it is
advisable to always check the luggage compartment to make sure that no
unnecessary loads are being transported.
Since the luggage rack increases the aerodynamic drag of the vehicle, you
should remove it when not needed. This will save, at a speed of 100-120
km/h (60-75 mph), approximately 12% of fuel.
Save electrical energy
The engine drives the alternator, thereby generating electricity. This implies
that any increase in power consumption also increases fuel consumption!
For this reason, switch off any unneeded consumption of electricity. Electri-
cal equipment which uses a lot of electricity includes the blower (at a high
setting), the rear window heating and the seat heating*. 
Environmental friendliness
Environmental protection is a top priority in the design, choice of materials
and manufacture of your new SEAT.
Constructive measures to encourage recycling
● Joints and connections designed for easy dismantling
● Modular construction to facilitate dismantling
● Increased use of single-grade materials.
● Plastic parts and elastomers are marked in accordance with ISO 1043,
ISO 11469 and ISO 1629.
Choice of materials
● Use of recycled materials.
● Use of compatible plastics in the same part if its components are not
easily separated. 

234Trailer
Trailer
Trailer towing What do you need to bear in mind when towing a trailer?
Your vehicle may be used to tow a trailer when fitted with the correct equip-
ment.
If you wish to retrofit a towing bracket, consult ⇒ page 236.
Connectors
Your vehicle is fitted with a 12-pin connector for the electrical connection
between the trailer and the vehicle.
If the trailer has a 7-pin plug you will need to use an adapter cable. This is
available in any Technical Service.
Trailer weight/drawbar load
Never exceed the authorised trailer weight. If you do not load the trailer up
to the maximum permitted trailer weight, you can then climb correspond-
ingly steeper slopes.
The maximum trailer weights listed are only applicable for altitudes up to
1000 m above sea level. With increasing altitude the engine power and
therefore the vehicle climbing ability are impaired because of the reduced
air density. The maximum trailer weight has to be reduced accordingly. The
weight of the vehicle and trailer combination must be reduced by 10% for
every further 1000 m (or part thereof). The gross combination weight is the
actual weight of the laden vehicle plus the actual weight of the laden trailer.
When possible, operate the trailer with the maximum permitted drawbar
load on the ball joint of the towing bracket, but do not exceed the specified
limit. The figures for
trailer weights and drawbar loads that are given on the data
plate of the towing bracket are for certification purposes only. The correct
figures for your specific model, which may be lower than these figures for
the towing bracket, are given in the vehicle documentation or in ⇒ chap-
ter Technical Data.
Distributing the load
Distribute loads in the trailer so that heavy objects are as near to the axle as
possible. Loads carried in the trailer must be secured to prevent them mov-
ing.
Tyre pressure
Set tyre pressure to the maximum permissible pressure shown on the stick-
er on the inside of the fuel tank flap. Set the tyre pressure of the trailer tyres
in accordance with the trailer manufacturer's recommendations.
Exterior mirrors
Check whether you can see enough of the road behind the trailer with the
standard rear vision mirrors. If this is not the case, you should have addi-
tional exterior mirrors fitted. Both exterior mirrors should be mounted on
hinged extension brackets. Adjust the mirrors to give sufficient vision to the
rear.
WARNING
Never transport people in a trailer. This could result in fatal accidents. 

235
Trailer
Note
● Towing a trailer places additional demands on the vehicle. We recom-
mend additional services between the normal inspection intervals if the ve-
hicle is used frequently for towing a trailer.
● Find out whether special regulations apply to towing a trailer in your
country. 
Ball coupling of towing bracket*
The ball coupling is provided with instructions on fitting and removing the
ball coupling of the towing bracket.
WARNING
The towing bracket ball coupling must be stored securely in the luggage
compartment to prevent them being flung through the vehicle and caus-
ing injury.
Note
● By law, the ball coupling must be removed if a trailer is not being towed
if it obscures the number plate. 
Driving tips
Driving with a trailer always requires extra care. Weight distribution
The weight distribution of a loaded trailer with an unladen vehicle is very
unfavourable. However, if this cannot be avoided, drive extra slowly to allow
for the unbalanced weight distribution. Speed
The stability of the vehicle and trailer is reduced with increasing speed. For
this reason, it is advisable not to drive at the maximum permissible speed
in an unfavourable road, weather or wind conditions. This applies especially
when driving downhill.
You should always reduce speed immediately if the trailer shows the slight-
est sign of
snaking. Never try to stop the “snaking” by increasing speed.
Always brake in due course. If the trailer has an overrun brake, apply the
brakes gently at first and then, firmly. This will prevent the jerking that can
be caused by locking of trailer wheels. Select a low gear in due course be-
fore going down a steep downhill. This enables you to use the engine brak-
ing to slow down the vehicle.
Reheating
At very high temperatures and during prolonged slopes, driving in a low
gear and high engine speed, always monitor the coolant temperature gauge
⇒ page 69.
Electronic Stability Control*
The ESC* system helps to stabilise the trailer in case of skidding or rocking. 
Safety FirstOperating instructionsPractical TipsTechnical specifications

246Checking and refilling levels
Checking and refilling levels
Fuel
Types of petrol
The correct grade of petrol is listed inside the fuel tank flap.
The vehicle is equipped with a catalytic converter and must only be run on
unleaded petrol. The petrol must comply with European Standard EN 228 or
German standard DIN 51626-1 and must be unleaded. You can refuel with a
maximum ethanol proportion of 10 % (E10). The types of petrol are differen-
tiated by their octane rating (RON).
The following titles appear on the corresponding adhesive on the fuel tank
flap:
Super unleaded 95 octane or normal 91 octane unleaded petrol
We recommend you use super 95 octane petrol. If this is not available: nor-
mal 91 octane petrol, with a slight decrease in power.
Super unleaded petrol with a minimum of 95 octanes
You should use super petrol with a minimum of 95 octanes.
If super is not available, in an emergency you may refuel with normal 91 oc-
tane petrol. In this case only use moderate engine speeds and a light throt-
tle. Refuel with super as soon as possible.
Super unleaded 98 octane or super 95 octane unleaded petrol
We recommend you use super plus 98 octane petrol. If this is not available:
super 95 octane petrol, with a slight decrease in power.
If super is not available, in an emergency you may refuel with normal 91 oc-
tane petrol. In this case only use moderate engine speeds and a light throt-
tle. Refuel with super as soon as possible. Petrol additives
The quality of the fuel influences the behaviour, performance and service
life of the engine. This is why the petrol you use should carry suitable addi-
tives already included by the petrol industry, free of metals. These additives
will help to prevent corrosion, keep the fuel system clean and prevent de-
posits from building up in the engine.
If good quality petrol with metal-free additives is not available or engine
problems arise, the necessary additives must be added when refuelling
⇒ 
.
Not all petrol additives have been shown to be effective. The use of unsuita-
ble petrol additives may cause significant damage to the engine and the
catalytic converter. Metal additives should never be used. Metal additives
may also be contained in petrol additives for improving anti-detonation rat-
ings or octane ratings ⇒ 
.
SEAT recommends “Genuine Volkswagen Group fuel additives for petrol en-
gines”. These additives can be bought at SEAT Authorised Services, where
information on how to use them can also be obtained.
CAUTION
● Do not refuel if the filler indicates that the fuel contains metal. LRP (lead
replacement petrol) fuels contain high concentrations of metal additives.
Using them may damage the engine!
● Never refuel with fuels containing a large proportion of ethanol (for ex-
ample, E50, E85). This could damage the fuel system.
● Just filling one full tank of leaded fuel or fuel containing other metal ad-
ditives would seriously impair the efficiency of the catalytic converter. 

247
Checking and refilling levels
● Only use fuel additives that have been approved by SEAT. Octane boost-
ing or anti-knock additives may contain metal additives that could seriously
damage the engine or the catalytic converter. These additives must not be
used.
● High engine speed and full throttle can damage the engine when using
petrol with an octane rating lower than the correct grade for the engine.
Note
● You may use petrol with a high octane number than the one recommen-
ded for your engine.
● In those countries where unleaded petrol is not available, you may refuel
with a fuel with a low lead content. 
Diesel Fuel
Please note the information on the inside of the fuel tank
flap.
We recommend the use of Diesel fuel which complies to European standard
EN 590. If diesel fuel which meets European standard EN 590 is not availa-
ble, the Cetane number (CZ) must, at minimum, be 51. If the engine is
equipped with a particulate filter, the sulphur content of the fuel must be
below 50 parts per million.
Winter-grade diesel
Summer fuel becomes thicker in winter and it is more difficult to start the
engine. For this reason petrol stations in some countries also offer winter
diesel with improved fluidity when cold.
CAUTION
● The vehicle is not designed for the use of biodiesel (FAME fuel). The fuel
system would be damaged if you used biodiesel.
● Do not mix fuel additives, the so-called “thinners”, petrol or similar ad-
ditives with diesel fuel.
● If poor-quality diesel fuel is used, it may be necessary to drain the fuel
filter more frequently than is specified in the Service Plan. We recommend
having this done by a specialised workshop. If water is allowed to collect in
the filter, this can cause engine performance problems. 
Natural gas
Natural gas
Natural gas, in addition to others, can be in compressed or liquid form.
Liquefied natural gas (LNG) is the result of heavy cooling of natural gas.
Therefore its volume is considerably reduced compared with compressed
natural gas (CNG). In vehicles with a natural gas engine, liquefied natural
gas cannot be directly refilled, given that the gas would expand excessively
in the vehicle gas tank.
Therefore, vehicles with a natural gas engine must only be refuelled using
compressed natural gas ⇒ 
.
Natural gas quality and consumption
Natural gas is divided into the groups H and L depending on its quality.
Gas type H has a superior heating power and inferior nitrogen and carbon
dioxide content than type L. The higher the heating power of the natural
gas, the lower the consumption will be.
However, the heating power and the proportion of nitrogen and carbon di-
oxide can fluctuate within the quality groups. Therefore, vehicle consump-
tion can also vary, even when using one type of gas only. 
Safety FirstOperating instructionsPractical TipsTechnical specifications

248Checking and refilling levels
The engine management automatically adapts to the natural gas used ac-
cording to its quality. Therefore, different quality gases can be mixed in the
tank, without the need for comprehensive draining before applying a differ-
ent quality gas.
The instrument panel display shows information on the current natural gas
quality ⇒ page 73.
Natural gas and safety
If you can smell gas or suspect that there is a leak ⇒ 
:
● Stop the vehicle immediately.
● Switch the ignition off.
● Open the doors to appropriately ventilate the vehicle.
● Extinguish cigarettes immediately.
● Move away from the vehicle or switch off objects that may cause sparks
or a fire.
● If you continue to smell gas, do not continue driving!
● Seek specialist assistance. Have the fault repaired.
WARNING
Failure to act when you can smell gas in the vehicle or when refuelling
can cause serious injuries.
● Carry out the necessary operations.
● Leave the danger zone.
● If necessary, warn the emergency services.
WARNING
The vehicle is not prepared to use liquefied natural gas (LNG) and this
fuel must not be added under any circumstances. Liquefied natural gas
can cause the natural gas tank to explode resulting in serious injury.
Note
Have natural gas system checked regularly by a specialised workshop in ac-
cordance with the Maintenance Programme. 
Filling the tank Filling the tank
Fig. 151 Fuel tank flap
with tank cap attached
The flap that covers the tank cap is unlocked and locked automati-
cally by the central locking.
Opening the fuel tank cap
– Open the fuel tank flap, by pressing on the left side.
– Unscrew the fuel tank cap anti-clockwise. 

249
Checking and refilling levels
– Place the cap in the housing on the hinge of the open flap
⇒ Fig. 151.
Closing the fuel tank cap
– Screw on the tank cap clockwise until it you hear it click into po-
sition.
– Close the tank flap. Make sure you hear it click into place.
If the automatic filler nozzle is operated correctly, it will switch itself off as
soon as the fuel tank is “full”. Do not try to put in more fuel after the nozzle
cuts out, as this will fill the expansion chamber in the fuel tank.
The correct fuel grade for your vehicle is given on a sticker on the inside of
the fuel tank flap. Further notes on fuel can be found at ⇒ page 246.
The capacity of the fuel tank is listed in the vehicle technical specifications
⇒ page 323.
WARNING
Fuel is highly flammable and can cause serious burns and other injuries.
● Do not smoke when filling the fuel tank or a canister. Naked flames
are forbidden in the vicinity due to the risk of explosion.
● Observe legislation governing the use, storage and carrying of a
spare fuel canister in the vehicle.
WARNING (Continued)
● For safety reasons we do not recommend carrying a spare fuel canis-
ter in the vehicle. In an accident the canister could be damaged and could
leak.
● If, in exceptional circumstances, you have to carry a spare fuel canis-
ter, please observe the following points:
–Never fill fuel into the spare fuel canister if it is inside or on top of
the vehicle. An electrostatic charge could build up during filling, caus-
ing the fuel vapour to ignite. Danger of explosion. Always place the
canister on the ground to fill it.
– Insert the filling nozzle as far as possible into the spare fuel canis-
ter.
– If the spare fuel canister is made of metal, the filling nozzle must
be in contact with the canister during filling. This helps prevent an
electrostatic charge building up.
– Never spill fuel in the vehicle or in the luggage compartment. Fuel
vapour is explosive. Risk of fatal accident!
CAUTION
● If any fuel is spilt onto the vehicle, it should be removed immediately. It
could otherwise damage the paintwork.
● Never run the tank completely dry. An irregular fuel supply could cause
misfiring. As a result, unburnt fuel could enter the exhaust system and dam-
age the catalytic converter.
● When filling the fuel tank after having run it completely dry on a vehicle
with a diesel engine , the ignition must be switched on for at least 30 sec-
onds before starting the engine. When you then start the engine it may take
longer than normal (up to one minute) for the engine to start firing. This is
because air needs to be bled from the fuel system while starting. 
Safety FirstOperating instructionsPractical TipsTechnical specifications

250Checking and refilling levels
For the sake of the environment
Do not overfill the fuel tank – it may cause the fuel to overflow if it becomes
warm.
Note
Diesel vehicles are fitted with a protective device that prevents the insertion
of the wrong fuel hose 1)
. It is only possible to refuel with Diesel nozzles.
● If the pump nozzle is worn, damaged, or if it is very small, it is possible
that it will not be able to open the protective device. Before trying to insert
the pump nozzle by turning it, try a different pump or request specialist
help.
● If you fill the tank from a reserve fuel canister, the protective device will
not open. One way to resolve this is to pour the fuel in very slowly. 
Refuelling natural gas
Fig. 152 Tank flap open:
gas filler mouth 1, filler
mouth retainer 2
Before refuelling, the engine and the ignition, mobile telephone and heat-
ing must be switched off separately
⇒ .
Read the instructions on how to use the natural gas pump carefully.
The vehicle is not prepared for refuelling with liquefied natural gas (LNG)
⇒ 
. Before refuelling with natural gas, make sure to add the appropriate
type of fuel ⇒ page 246.
Opening the fuel tank cap
The natural gas filler mouth is behind the fuel tank cap, next to the petrol
filler mouth.
● Unlock the vehicle with the key or with the central locking button 
situ-
ated on the driver door ⇒ page 87.
● Press on the rear area of the flap and open it.
Refuelling
Thing to note: if the ambient temperature is very high, the natural gas pump
protection against overheating may disconnect this automatically.
● Remove the plug from the gas filler mouth ⇒ Fig. 152 1
.
● Connect the pump filling nozzle to the gas filler mouth.
● The fuel tank will be full when the pump compressor automatically cuts
the supply.
● If you wish to finish refuelling in advance, press the button on the pump
to stop the flow.
Closing the fuel tank cap
● Check that the gas filler mouth retainer 2
is not trapped with the filler
nozzle. If necessary, place it in the filler mouth again.
● Insert the plug in the filler mouth.
● Close the tank flap. Make sure you hear it click into place. 
1)
according to the country

251
Checking and refilling levels
WARNING
Natural gas is a highly explosive, easily flammable substance. Incorrect
handling of the natural gas can cause accidents serious burns and other
injuries.
● Before refuelling with natural gas, engage the filler neck correctly. If
you smell gas, stop refuelling immediately.
WARNING
The vehicle is not prepared to use liquefied natural gas (LNG) and this
fuel must not be added under any circumstances. Liquefied natural gas
can cause the natural gas tank to explode resulting in serious injury.
Note
● The filling nozzles of all natural gas pumps might not be operated in the
same way. If you do not know, ask a qualified employee at the petrol station
to do the refuelling.
● Noises heard when refuelling are normal and do not indicate the pres-
ence of damage to the system.
● The vehicle natural gas system is prepared both for refuelling with a
small compressor (slow refuel) and a large compressor (fast refuel) in natu-
ral gas service stations. Bonnet
Working on components in the engine compartment
Extra caution is necessary when working on components in
the engine compartment. Always be aware of the danger of injury and scalding as well as the risk of
accident or even fire when working in the engine compartment (e.g. when
checking and refilling fluids). Always observe the warnings listed below
and follow all general safety precautions. The engine compartment of the
vehicle is a potentially hazardous area ⇒ 
.
WARNING
● Switch the ignition off.
● Remove the ignition key.
● Apply the handbrake.
● If the vehicle has a manual gearbox, place the lever in neutral; if it
has an automatic gearbox, place the selector lever in position P.
● Wait for the engine to cool down.
● Keep children away from the engine compartment.
● Never spill liquids used for vehicle operation on the engine compart-
ment, as these may catch fire (e.g. the antifreeze in coolant).
● Take care not to cause short circuits in the electrical system, especial-
ly when working on the battery.
● If working inside the engine compartment, remember that, even when
the ignition is switched off, the radiator fan may start up automatically,
and therefore there is a risk of injury.
● Do not unscrew the cap on the coolant expansion tank when the en-
gine is hot. The cooling system is under pressure. 
Safety FirstOperating instructionsPractical TipsTechnical specifications

252Checking and refilling levels
WARNING (Continued)
● Protect face, hands and arms by covering the cap with a large, thick
rag to protect against escaping coolant and steam.
● If it is necessary to work in the engine compartment while the engine
is running, the rotating components (for example, poly-V belt, alternator,
radiator fan) and the high voltage ignition system are an additional haz-
ard.
● Observe the following additional warnings if work on the fuel system
or the electrical system is necessary:
–Always disconnect the battery from the on-board network.
– Do not smoke.
– Never work near naked flames.
– Always keep an approved fire extinguisher immediately available.
CAUTION
When changing or topping up service fluids, make absolutely certain that
you fill the fluids into the correct reservoirs. Using the wrong fluids could
cause serious malfunctions and engine damage!
For the sake of the environment
Inspect the ground underneath your vehicle regularly so that any leaks are
detected at an early stage. If you find spots of oil or other fluids, have your
vehicle inspected at the workshop.
Note
On right-hand drive vehicles* some of the containers/reservoirs mentioned
below are located on the other side of the engine compartment. Opening the bonnet
The bonnet is released from inside the vehicle.
Fig. 153 Release lever in driver footwell and cam below the bonnet
Check that the windscreen wiper arms are not unfolded. Otherwise
the paint may be damaged.
The bonnet can only be unlocked when the driver door is open.
– Pull the lever under the dash panel in the direction of the arrow
1
⇒ Fig. 153.
– Lift the bonnet slightly ⇒ 
.
– Press the release catch under the bonnet upwards ⇒ Fig. 153
2
. This will release the arrester hook under the bonnet.
– Open the bonnet. Release the bonnet stay and secure it in fix-
ture designed for this in the bonnet. 