2008 AUDI A4 check engine

Checking and topping up fluids 256Closing the bonnet– To close the bonnet, pull it down to overcome the spring
pressure.
– Then let it drop into the catches; do not press down ⇒.
WARNING
•
For safety reasons the bonnet must always be completely
closed when the vehicle is moving. After closing it always check
that it is properly secured. The bonnet must be flush with the adja-
cent body panels.
•
Should you notice that the bonnet is not safely secured when
the vehicle is moving, stop the vehicle immediately and close the
bonnet properly, otherwise it could cause an accident.
Engine compartment layoutEngine compartment layout
Main components for checking and refillingFig. 252 Typical locations of fluid containers, engine oil dipstick and engine oil
filler cap
Jump-start terminal (+) under a cover . . . . . . . . . . . . .
Brake fluid reservoir (
) . . . . . . . . . . . . . . . . . . . . . . . .
Engine oil filler cap (

) . . . . . . . . . . . . . . . . . . . . . . . .
Engine oil dipstick* (orange) . . . . . . . . . . . . . . . . . . . . .
Radiator expansion tank () . . . . . . . . . . . . . . . . . . . . .
Jump-start terminal (-) with hexagon head . . . . . . . . .
Windscreen washer container (
) . . . . . . . . . . . . . . . .
Hydraulic fluid reservoir for power steering . . . . . . . .
A1
265, 294
A2
262
A3
259
A4
258
A5
261
A6
265, 294
A7
267
A8
225
document_0900452a81b1b9de.book Seite 256 Donnerstag, 26. Juli 2007 9:16 09

Checking and topping up fluids257
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data The positions of the engine oil filler cap and the engine oil dipstick
⇒page 256, fig. 252 (items and ) may be different on some
engine versions.
Engine oilGeneral notesWe recommend that you have the oil change carried out by an Audi
dealership / qualified workshop according to the intervals stated in
the Service Schedule or according to the service interval display in
the instrument cluster.
Whether your vehicle is serviced at flexible service intervals or fixed
service intervals is shown in the Service Schedule.
The correct oil specifications for your engine are listed in the Te c h -
nical data section ⇒page 323, “Performance, weights and dimen-
sions”.
Check that the specifications quoted (VW standards) appear on the
container either singly or in combination with other specifications.
Flexible service intervals (Audi LongLife Service*)
Special engine oils ⇒page 323, “Performance, weights and dimen-
sions” have been developed as part of the Audi LongLife Service
(⇒“Service Schedule”).
This type of oil must be used if you intend to take advantage of the
extended maintenance intervals allowed by the Audi LongLife
Service.•
Do not mix the LongLife oil with oil intended for fixed service
intervals, as the requirements for the extended service intervals are
then no longer guaranteed.
•
In exceptional circumstances, if the engine oil level is too low
⇒page 258 and you cannot obtain the specified LongLife oil, you
can put in a small quantity of oil for fixed service intervals -
⇒page 323, “Performance, weights and dimensions”. This should not be done more than once and no more than 0.5 litres should be
used.
Fixed service intervals (Inspection Service)*
If you do not take advantage of the LongLife service for your car, you
can use the oils for fixed service intervals - ⇒page 323, “Perform-
ance, weights and dimensions”. In this case, your car must be serv-
iced after a fixed interval of 1 year / 15,000 km (9,000 miles) – see
Service Schedule.
•
In exceptional circumstances, if the engine oil level is too low
⇒page 258 and you cannot obtain the oil specified for your vehicle,
you can put in a small quantity of oil conforming to the specification
ACEA A2 or ACEA A3 (petrol engines) or ACEA B3 or ACEA B4 (diesel
engines). This should not be done more than once and no more than
0.5 litres should be used.
Vehicles with diesel particulate filter*
The Service Schedule states whether your vehicle is fitted with a
diesel particulate filter.
•
Vehicles with diesel particulate filter must only be filled with
engine oil VW 507 00. This oil can be used regardless of whether the
vehicle is serviced at flexible service intervals (Audi LongLife
Service) or fixed service intervals.
•
Avoid mixing this oil with other engine oils.
•
In exceptional circumstances, if the engine oil level is too low
⇒page 258 and you cannot obtain the oil specified for your vehicle,
you can put in a small quantity of oil conforming to the specification
VW 506 00 / VW 506 01 or VW 505 00 / VW 505 01 or ACEA B3 /
ACEA B4. This should not be done more than once and no more than
0.5 litres should be used.
A3
A4
document_0900452a81b1b9de.book Seite 257 Donnerstag, 26. Juli 2007 9:16 09

Checking and topping up fluids 258Checking the oil level (with dipstick)Checking the oil level
– Park your vehicle on a level surface.
– Allow the warm engine to run briefly at idling speed and
then switch off the ignition.
– Wait approx. 2 minutes.
– Pull out the dipstick. Wipe the dipstick with a clean cloth
and insert it again, pushing it in as far as it will go.– Then pull the dipstick out again and check the oil level
⇒fig. 253 or ⇒fig. 254. If the oil level is too low, add
more engine oil ⇒page 259.
Oil level in area
–Do not top up oil.
Oil level in area
–Oil can be topped up. After topping up the oil level should
be in area .
Oil level in area
–Oil must be topped up. After topping up the oil level
should be in area .
Depending on how you drive and the conditions in which the car is
used, oil consumption can be up to 0.5 ltr./1000 km. Oil consump-
tion is likely to be higher for the first 5000 km. You should therefore
check the oil level at regular intervals, ideally every time you fill the
tank, and also before setting off on a long trip.
Fig. 253 Variant 1:
Markings on oil
dipstickFig. 254 Variant 2:
Markings on oil
dipstick
AaAb
Aa
AcAa
document_0900452a81b1b9de.book Seite 258 Donnerstag, 26. Juli 2007 9:16 09

Checking and topping up fluids259
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
Applies to vehicles: without oil dipstickChecking the oil level (without dipstick)
You can check the engine oil level via the sound system or
MMI*.– Select: Function selector button > Oil level.
– Park your vehicle on a level surface.
– Allow the warm engine to run briefly at idling speed and
then switch off the ignition.
– Wait approx. 2 minutes.
– Read off the oil level on the display ⇒fig. 255. Top up the
engine oil if the bar in the oil level display is near the
“min” mark ⇒page 259.Depending on how you drive and the conditions in which the car is
used, oil consumption can be up to 0.5 ltr./1000 km. Oil consump-
tion is likely to be higher for the first 5000 km.
Note
The oil level display is intended solely for information purposes. An
oil level warning will appear in the instrument cluster if the oil level
is too low. Add more oil ⇒page 259. If the bonnet has been opened, the current oil level will be shown in the instrument cluster the next
time the ignition is switched on.
Topping up the engine oil

–Unscrew cap

from oil filler opening ⇒fig. 256.
– Carefully put in the specified grade of oil ⇒page 323
0.5 litres at a time.
– Check the oil level again after two minutes by calling up
the sound system or MMI* display or using the oil
dipstick ⇒page 258.
– If the oil level is too low, add more engine oil.
– Replace the oil filler cap carefully and push the dipstick
all the way in (on vehicles with dipstick).
WARNING
•
Ensure that no oil comes into contact with hot engine compo-
nents when topping up: this could cause a fire.
•
Wash your skin thoroughly if it comes into contact with engine
oil.
Fig. 255 Display: Oil
level
CAR
Fig. 256 Engine
compartment: Engine
oil filler cap
document_0900452a81b1b9de.book Seite 259 Donnerstag, 26. Juli 2007 9:16 09

Checking and topping up fluids 260
Caution•
The oil level must never be above area ⇒page 258, fig. 254,
as this may result in damage to the catalytic converter or to the
engine. On vehicles without an oil dipstick, you can check the oil
level via the sound system or MMI*. Contact a qualified workshop to
extract the engine oil if necessary.
•
No additives should be used with engine oil. Any damage caused
by the use of such additives would not be covered by the factory
warranty.For the sake of the environment
•
Never pour oil down drains or into the ground.
•
Always observe statutory requirements when disposing of
empty oil canisters.
Cooling systemCoolant
The purpose of the coolant is to carry heat away from the
engine. The correct amount of anti-freeze is important to
prevent the cooling system from freezing in winter.The cooling system is filled for life at the factory, so the coolant does
not need to be changed. The coolant consists of a mixture of water
and anti-freeze additive G12++. This is a glycol-based anti-freeze
with anti-corrosion additives.
Anti-freeze additive
The amount of anti-freeze additive required depends on the temper-
atures to be expected in the winter season. If the anti-freeze concen-
tration is too low the coolant can freeze, resulting in failure of the
cooling system and heater.The cooling system is filled at the factory with the correct amount of
anti-freeze for the country concerned.
In most cases the mixture consists of 60% water and 40% additive.
This mixture gives the required anti-freeze protection at tempera-
tures down to -25 °C and protects the alloy parts of the cooling
system against corrosion. It also prevents scaling and raises the
boiling point of the coolant.
Countries with warm climate
The coolant concentration must not be reduced by adding plain
water, even in the summer or in warm climates. The concentration
of the anti-freeze additive must always be at least 40%.
Countries with cold climate
If greater anti-freeze protection is required in very cold climates, the
proportion of the anti-freeze additive G12++ can be increased. A
concentration of 60% offers protection down to about - 40 °C. The
concentration of the anti-freeze additive must not be more than
60%, otherwise this would reduce the anti-freeze protection. In addi-
tion, the cooling effect will be adversely affected.
Vehicles for export to countries with a cold climate (such as Sweden,
Norway and Finland) are supplied with antifreeze protection down
to about -35 °C. The concentration of the antifreeze additive for
these countries should always be at least 50%.
Caution
•
It is advisable to have the cooling system checked before the
winter season to make sure that the antifreeze concentration is
adequate for the conditions to be expected. This applies particularly
if you intend to take the car into a colder climate zone. If necessary,
have the anti-freeze concentration increased to 50 - 60% as required.
•
Use only anti-freeze additive G12++, an additive meeting the
specification “TL 774 G”. Other additives may give considerably
inferior corrosion protection. The resulting corrosion in the cooling
system can lead to a loss of coolant, causing serious damage to the
engine.
Aa
document_0900452a81b1b9de.book Seite 260 Donnerstag, 26. Juli 2007 9:16 09

Checking and topping up fluids261
Controls
Safety
Driving tips
General maintenance
Self-help
Technical data
•
The coolant additive G12++ can be mixed only with additives
G12+ and G12.
Checking coolant level
The coolant level can be checked at a glance.– Switch off the ignition.
– Read off coolant level on radiator expansion tank
⇒fig. 257. When the engine is cold it should be between
the “MIN” and “MAX” marks. When the engine is hot it
may be slightly above the “MAX” mark.The coolant level should be checked with the engine switched off.
The coolant level is monitored by a warning lamp in the instrument
cluster ⇒page 33. However, we recommend that it should be
checked occasionally.
Coolant losses
Any loss of coolant normally indicates a leak in the cooling system.
In this case the cooling system should be inspected by a qualified
workshop without delay. It is not sufficient merely to top up the
coolant.If there are no leaks in the system, a loss of coolant can only occur
if the coolant boils and is forced out of the system as a result of
overheating.
Caution
Radiator sealants must not be added to the coolant. Such additives
could seriously impair the function of the cooling system.Topping up the coolant
Be careful when topping up coolant.– Switch off the engine.
– Wait for the engine to cool down.
– Cover the cap on the expansion tank ⇒fig. 257 with a
cloth, and carefully unscrew the cap anti-clockwise
⇒.
– Add coolant.
– Screw the cap on again tightly.Make sure that the coolant meets the required specifications
⇒page 260, “Coolant”. Do not use a different type of additive if anti-
freeze additive G12++, G12+ or G12 is not available. In this case use
only water and bring the coolant concentration back up to the
correct level as soon as possible by putting in the specified additive.
Always top up with fresh, unused coolant.
Do not fill above the “MAX” mark. Excess coolant is forced out of the
system through the valve in the filler cap when the engine gets hot.
If a lot of coolant has been lost, wait for the engine to cool down
before putting in cold coolant. Failure to do so could result in
serious engine damage.
Fig. 257 Engine
compartment: Mark-
ings on radiator expan-
sion tank
document_0900452a81b1b9de.book Seite 261 Donnerstag, 26. Juli 2007 9:16 09

Checking and topping up fluids 262
WARNING
•
The cooling system is under pressure. Do not unscrew the cap
on the expansion tank when the engine is hot: you could be
scalded by escaping steam
•
The coolant and coolant additive can be a health hazard. Store
the coolant additive in the original container in a safe place out of
reach of children – risk of poisoning.For the sake of the environment
Drained off coolant should not be used again. Drain off the used
coolant into a suitable container and dispose of it in the proper
manner (observe environmental regulations).Radiator fan
The radiator fan can start running spontaneously.The radiator fan is driven by the engine via a poly V-belt. The speed
of the fan is varied by a viscous clutch according to the temperature.
There is also an auxiliary electric fan, which cuts in automatically
whenever the temperature of the coolant and the engine compart-
ment rises above a certain level.
The auxiliary fan can continue to run for as long as 10 minutes after
stopping the engine – even after the ignition is switched off. It may
also start running suddenly ⇒ after a while if•
residual heat raises the coolant temperature, or
•
the hot engine compartment is additionally heated up by the
sun.
WARNING
When working in the engine compartment be aware that the radi-
ator fan may start running suddenly – risk of injury.
Brake fluidChecking brake fluid level
The brake fluid level can be checked at a glance.– Check the fluid level on the brake fluid reservoir
⇒fig. 258. It should always be between the “MIN” and
“MAX” marks.In right-hand drive vehicles the brake fluid reservoir is on the other
side of the engine compartment.
The fluid level may drop slightly after a period of time due to the
automatic compensation for brake pad wear. This is quite normal.
However, if the level goes down noticeably in a short time, or drops
below the “MIN” mark, there may be a leak in the brake system. If
the fluid level in the reservoir is too low, this will be indicated by the
brake warning lamp ⇒page 32. If this should happen, take the car
to a qualified workshop immediately and have the brake system
inspected.
Fig. 258 Engine
compartment: Mark-
ings on brake fluid
reservoir
document_0900452a81b1b9de.book Seite 262 Donnerstag, 26. Juli 2007 9:16 09

Checking and topping up fluids 264Please note that certain convenience features, such as the Audi
advanced key*, the remote control key or the electrical seat adjust-
ment may not be available when you unlock the vehicle. These func-
tions will be restored when you switch on the ignition and start the
engine.
Winter conditions
At low temperatures the battery has to work very hard. It also
provides only a fraction of the starting power it has at normal
temperatures.
For this reason, we recommend having the battery checked and
charged if necessary before the start of winter ⇒page 265.
WARNING
•
All work on batteries requires specialist knowledge. For queries
regarding the vehicle battery please contact an Audi dealership or
other qualified workshop (risk of chemical burns / risk of explo-
sion).
•
The battery must not be opened. Do not attempt to make any
changes to the electrolyte level of the battery. Otherwise, there is
a risk that a mixture of oxygen and hydrogen gas can accumulate
and cause an explosion.Note
If the vehicle is to be left standing for a period of several weeks at
extremely low temperatures, the battery should be removed from
the vehicle. This ensures that it cannot “freeze up” and be
damaged.
Important safety warnings for handling a car battery
All work on batteries requires specialist knowledge.The vehicle battery is located under the floor panel in the luggage
compartment.
WARNING
Always be aware of the danger of injury and chemical burns as
well as the risk of accident or fire when working on the battery and
the electrical system.•
Wear safety glasses. Do not allow acid or lead particles to come
into contact with eyes, skin or clothing.
•
Battery acid is extremely corrosive. Wear protective gloves and
safety glasses. Do not tilt the battery - acid can leak out of the
vapour vent. If electrolyte should splash into the eyes rinse at once
for several minutes using clear water. Then seek medical care
immediately. Neutralize any acid splashes on the skin or clothing
with soap solution, and rinse off with plenty of water. If acid is
swallowed by mistake, consult a doctor immediately.
•
Keep open flames, sparks, uncovered lights and lit cigarettes
away from battery. Avoid sparks (including those from static

Wear safety glasses!

Battery acid is extremely corrosive. Wear protec-
tive gloves and safety glasses.

Keep open flames, sparks, uncovered lights and
lit cigarettes away from battery!

A highly explosive mixture of gases is given off
when the battery is under charge!

Keep children away from the battery and battery
acid.
document_0900452a81b1b9de.book Seite 264 Donnerstag, 26. Juli 2007 9:16 09