check engine AUDI S6 2008 Owner's Guide

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Checking and filling
Engine hood
Releasing the engine hood
The engine hood is released from inside the vehicle.
-Open the driver's door .
Fig. 229 Driver's side
footwell: engine hood
release lever
-Pull the release lever on the left under the instrument
panel
=> fig. 229 in the direct ion of the arrow.
The hood pops up slightly under spring pressure. •
Opening the engine hood
Fig. 230 Release lever
under the engine hood
Before opening the engine hood, make sure that the wind­
shield wipers are flat against the windshield. Otherwise,
they could damage the paint on the hood.
Lift the hood slightly =>&, .
Pull up on the release under the hood => fig. 230. This
releases the catch.
- Open the hood all the way.
The hood is kept in the open position by two gas struts.
& WARNING
Hot engine coolant can burn you.
• To reduce the risk of being burned, never open the hood if you
see or hear steam or coolant escaping from the engine compart­
ment. Wait until no steam or coolant can be seen or heard before
carefully opening the hood. •

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•
Closing the engine hood
- Pull the hood down until the pressure from the struts is
reduced .
- Let the hood
drop down and latch in place. Do not try to
push it shut;
it may fail to engage => &.
& WARNING
A hood that is not completely latched could fly up and block your
view while driving.
• When you close the engine hood, check it to make sure the
safety catch has properly engaged. The hood should be flush with
the surrounding vehicle body parts.
• If you notice while driving that the hood is not secured prop­
erly, stop at once and close it. •
Working in the engine compartment
Be especially careful whenever you work in the engine
compartment.
Whenever you must perform any work in the engine compartment,
for example checking and filling different fluids, there is a risk of injury, burns and accidents. To prevent personal injury always
observe the following WARNINGS. The engine compartment of any
vehicle is a hazardous area
~ & .
& WARNING
To help avoid injury, before you check anything under the hood :
• Turn off the engine.
• Remove the ignition key.
• Apply the parking brake .
& WARNING (continued)
• Move selector lever to "P" (Park).
• Always let the engine cool down. Hot components will burn
skin on contact.
• To reduce the risk of being burned, never open the hood if you
see or hear steam or coolant escaping from the engine compart­
ment. Wait until no steam or coolant can be seen or heard before
carefully opening the hood.
• Keep children away from the engine compartment .
• Never spill fluids on hot engine components. They can cause a
fire.
• Never touch the radiator fan. The auxiliary electric fan is
temperature controlled and can switch on suddenly.
• Never open the coolant reservoir cap when the engine is still
warm . The coolant system is pressurized and hot coolant could
spray out.
• Protect your face, hands and arm from steam or hot engine
coolant by placing a thick rag over the cap when you open the
coolant reservoir.
• If work on the fuel system or the electrical system is necessary :
- Always disconnect the battery.
- Never smoke or work near heaters or open flames . Fluids in
the engine compartment could start a fire.
- Keep an approved fire extinguisher immediately available.
• To avoid electrical shock and personal injury while the engine
is running or being started, never touch:
- Ignition cables
- Other components of the high voltage electronic ignition system.
• If you must perform a check or repair with the engine running: -First, fully apply the parking brake, move selector lever to "P"
(Park). .,
Vehicle care
I t •

-~_C_ h_e _c _ k_ i_n ...:::g::;...._ a_n_ d_ f_ i_ll _in -'g:::;.._ ___________________________________________ _
current list of oils (manufacturers, brand names etc.) that conform
t o Audi oi l standard VW 502 00 .
Changin g the engine oil
The engine oil and oil filter must be changed according to the
mi leage (ki lometers) and time intervals specified in your vehicle's
Maintenance
& Warranty booklet. Do not exceed these interva ls -
harmful deposits from old engine oil can reduce engine perfor­
mance and can lead to expensive engine repairs.
Changing the oi l at the recommended intervals is so very important
because the lubricating prope rties of oi l decrease gradual ly during
normal vehicle use . If you are not sure when you have your oil
changed, ask your author ized Audi Serv ice Advisor.
Under some circumstances the engine oil should even be changed
more frequently. Change oil more often if you dr ive mostly short
distances, operate the vehicle in dusty areas or mostly under stop ­
and -go t raffic conditions, or when you use your vehicle where
temperatures stay be low freezing point for long per iods.
Detergent additives in the oil will make fresh oil look dark after the
engine has been running for a short time . This is normal and is not
a reason to change the oil more often than recommended.
Damag e or malfunctions due to lack o f mainten anc e
It is essentia l that you change your oi l at the recommended interva ls
using on ly engine oil that complies with Audi oil standard
VW 502 00. Your Limited New Vehicle Warranty does not cover damage or ma lfunctions due to failure to follow recommended
main tenance and use requirements as set forth in the Aud i Owner's
Manual and Maintenance
& Warranty booklet. Your dealer wi ll have
t o deny warranty cove rage unless you present to the dealer p ro o f in
the form of Service or Repair Orders that all schedu led maintenance
was pe rformed in a timely manner. •
Engine oil consumption
The engine in your vehicle depends on an adeq uate
amount of oil t o lubric ate and c ool all of its m oving parts.
In order to provide effective lubrication and coo ling of interna l
engine components, al l interna l combustio n eng ines consume a
certain amount of oil. Oil consumption varies from engine to engine
and may change significant ly over the life of the engine . Typ ically,
engines with a specified break-in period (see=> page 267) consume
more oil du ring the break-in period than they consume after oil
consumption has stabi lized .
Unde r normal conditions, the rate of oil consumption depends on
the quality and v iscosity of the oil, the RPM (revolutions per minute)
at which the engine is operated, the ambient temperature and road
cond itions. Fur ther factors are the amount of oil di lu tion from wate r
condensation or fue l residue and the oxidation leve l of the oi l. As
any engine is subject to wear as mileage bu ilds up, t he oil consump ­
tion may increase over time until replacement of worn components
may become necessa ry .
With all these variables coming into play, no standard rate o f oi l
consumption can be established or specified . There is no alternative
t o regula r and frequent checking of the oil level, see
Note .
If the yel low engine oil level warning symbo l in the instrument
clus ter lights up, yo u should check the oil level as soon as
possible with the oil dipstick=> page 301. Top off the oil at your
ea rliest convenience => page 302 .
& WARNING
Before you check anything in the engine compartment , always
read and heed all WARNING S
=> & in "Working in the engine
compartment " on
page 297.

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0 Note
Driving with an insufficient oil level is likely to cause severe damage
to the engine.
[ i] Tips
• The oil pressure warning display~ is not an indicator of the oil
level. Do not rely on it. Instead, check the oil level in your engine at
regular intervals, preferably each time you refuel, and always before
going on a long trip.
• If you have the impression your engine consumes excessive
amounts of oil, we recommend that you consult your Audi dealer to
have the cause of your concern properly diagnosed. Keep in mind
that the accurate measurement of oil consumption requires great
care and may take some time . Your Audi dealer has instructions
about how to measure oil consumption accurately. •
Checking the engine oil level
Fig. 232 Illustration of
principle 1: Markers on
oil dipstick Fig
. 233 Illustration of
principle 2: Markers on
oil dipstick
Before you check anything in the engine compartment,
always read and heed all WARNINGS=> & in "Working in
the engine compartment" on
page 297.
Determining oil level
-Park your vehicle so that it is horizontally level.
- While at operating state temperature, briefly let the
engine run at idle and then shut it off.
- Wait approx. two minutes.
- Pull out the oil dipstick. Wipe off the oil dipstick with a
clean cloth, and slide it back in as far as it will go.
Pull it back out and read off the oil level=> fig. 232 or
=> fig. 233. Top off the engine oil, if applicable
=>
page 302.
Oil level within range @
- Do not add oil.
Oil level within range @
-You can add oil. Afterwards, the oil level should be within
range @. _,,,
Vehicle care I I irechnical data

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Oil level within range
©
- You must add oil. Afterwards, the oil level should be
within range@.
The oil level needs to be checked at regular intervals. The best times
to do this are whenever you refuel and prior to long tr ips. •
Adding engine oil 'l:::1':
Fig. 234 Engine
compartment: Oil filler
cap locat ion
Before you check anything in the engine compartment,
always read and heed all WARNINGS~ & in "Working in
the engine compartment" on
page 297.
Unscrew the cap ~ fig. 234.
Carefully top off with the appropriate o il in 0.5 liter doses.
- Check the oil level again after two minutes ~
page 301.
Top off the oil again, if necessary.
Screw the cap back on the filling hole and slide the o il
dipstick in as far as it will go.
& WARNING
• While topping off, the oil must not come in contact with hot
engine parts -fire hazard!
• The oil filler cap must be properly secured to prevent oil from
being sprayed on the hot engine and exhaust system when the
engine is running -fire hazard!
• If your skin has come in contact with the engine oil , you must
subsequently cleanse it thoroughly.
0 Note
• T he oil level must not be above range @- danger of converter or
engine damage! Contact an au thorized dealership to draw off oil, if
necessary .
• Audi does not recommend the use of oil additives. They may
damage the engine and adversely affect your New Vehicle Warranty.
• Under no circumstances can the oil come in contact with the
sewage network or the soil.
• Observe and follow legal regulations when disposing of empty
oi l containers .•
Changing the engine oil
We recommend that have your oil changed by an autho­
rized Audi dealer or a qualified service station .
Before you check anything in the engine compartment, always read
and heed all WARNINGS ~
& in "Working in the engine compart ­
ment" on
page 297.
The engine oil must be changed according to the intervals specified
in your Maintenance
& Warranty booklet. This is very important ...

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le as t 50% b ut not mor e th an 60 % to maintain antifreeze protection
and cooling efficiency . If the coo lant frost protection is too low, the
coo lant could freeze and damage the vehicle heating and engine
cooling system.
For year -round driving, antifreeze is added at the factory for temper­
atures down to:
• -31 °F ( -35 °C) USA
• -40 °F ( -40 °C) Canada.
You can m ix the
Gl 2 + coolant additive with other add itives (for
example
Gl 1 or Gl 2). A lways check with your authorized Audi
dea ler .
& WARNING
Before you check anyt hing in the engine comp artment , alw ays
re ad and heed all WARNINGS ~
& in "Working in the eng ine
co mpar tm ent " o n
pag e 297.
0 Note
• Before win ter sets in, have the coolant checked to see if the
coolant additive in your vehicle is sufficient to meet the climate
conditions. This is especia lly important if you live in a region where
the winter is extremely cold. I f necessary, increase the proportion of
coo lant additive to 60%.
• When adding coolant additive to your coo ling system,
remember:
-We recommend using only coolant additive
Gl 2+ (check the
label) for your vehicle. This coolant addit ive is available at autho ­
rized Audi dealers. Other types of antifreeze can significantly
reduce corrosion protect ion . T he resulting corrosion can cause a
loss of coolant and serious engine damage.
• Do not add any type of radiator leak sealant to your vehicle's
engine coolant. Adding radiator repair fluid may adversely affect the function and performance of your cooling system and cou
ld result
in damage not c overed by your New Vehicle Limited Warranty. •
Checking the engine coolant level
The engine coolant level can be checked with a quick
glance.
F ig . 235 Eng ine
c o mpartm ent : Cool ant
ex pa nsion tank
Before you check anything in the engine compartment,
always read and heed all WARNINGS~
& in "Working in
the e ngin e compa rtment" on
page 297 .
Turn off the ignition.
Re ad the en gine coo lant leve l from the coo lant exp an­
sio n ta n k~ fig. 235. With a cold eng ine, the coolan t leve l
sho uld be between the "m in" and "max" markings. W hen
t h e eng ine is warm, the level may be s lightly abov e the
"max" marking .
The location of the coolant expansion tank can be seen in the
engine compartment illustration~
page 298.
To obtain an accurate reading, the engine must be switched off .
T he expansion tank in your vehicle is equipped with an e lectric
coo lant leve l sensor.

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•
When the coolant level is too low , the warning light in the Auto­
Check System =>
page 33will blink un til you add coo lant and the
level has been restored to normal. Even though there is an electric
coolant leve l sensor, we still recommend you check the coo lant level
from time to time .
Coola nt lo ss
Coolant loss may indicate a leak in the cooling system . In the event
of coolant loss, the coo ling sys tem should be inspected immedi ­
ately by your authorized Audi dealer . It is not enough merely to add
coolant.
In a
s ealed system, losses can occur only if the boiling po int of the
coolant is exceeded as a result of overheating.
0 Note
Do not add any type of radiator leak sea lant to your vehicle's engine
coolant . Adding radiator repair fluid may adversely affect the func ­
tion and performance of your cooling system and could resu lt in
damage not covered by your New Vehic le Limited War ranty .•
Adding coolant
Be very careful when adding engine coolant.
Before you check anything in the engine compartment,
always read and heed all WARNINGS => & in "Working in
the engine compartment" on
page 297 .
- Tu rn off the engine .
- L et the engine coo l dow n.
- Place a t hick rag over the coolant expansion tank
=> page 304, fig . 235 and carefully tw ist t he cap counter­
cloc kw ise
=> & .
- Add coolant. - Twist the cap
on agai n
tightly.
Replacement engine coolant must conform to exact specifications
=>
page 303, "Coolant". If in an emergency coolant additive G12 + is
not avai lable, do
not use a different additive . Use p lain water
instead until you can get the correct additive and can restore the
correct ratio . This should be do ne as soon as possible.
If you have lost a considerable amount of coolant, then you should
add cold antifreeze and cold water only when the engine is cold .
Always use
new engine coolant when refilling .
Do not fil l coolant above the "MAX" mark. Excess coolant will be
forced out through the pressure relief va lve in the cap when the
engine becomes ho t.
& WARNING
• The cooling system is under pressure and can get ver y hot.
Redu ce the risk of sc alding from hot coolan t by follow ing the se
s tep s.
- Turn off th e en gine and allo w it to cool down .
- Protect your fa ce , ha nd s and arm s from e sc a pi ng fluid and
s tea m by cov ering the c ap with a large , thick rag.
- Tur n the cap slo wly an d very ca refully in a counter -clockw is e
dire ction whil e applying light , downward pres sure on the top
o f the cap.
- To av oid bei ng burn ed , do n ot spill antifree ze or cool ant on
the e xhau st sy stem or h ot e ngi ne part s. Under cert ain co ndi­
tion s, the ethylen e gl ycol in engin e co olant c an c atch fire .
• Antifr eeze is po iso nous. Alwa ys store antifree ze in its or igin al
c ontainer and well out of the reach of c hildren .
• If you dra in t he coola nt, it mu st b e ca ught and sa fel y stor ed in
a prop er container clearly mark ed "poi son ".
~
Vehicle care I t •

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0 Not e
• Coolant pollutes the environment and cou ld cause an engine
fire. Excess coolant will be forced out through the pressure relief
valve in the cap when the engine becomes hot.
• If, in an emergency, only water can be added, the correct ratio
between water and antifreeze ~
page 303 must be restored as soon
as possible .
ci> For the sake of the environment
Dra ined coolant should not be reused . Always dispose of used
coolant whi le observing all environmental regulations. •
Radiator fan
The radiator fan switches on automatically by itself.
The rad iator fan is driven by the eng ine v ia the V-be lt . The v iscous
clutch regulates the speed of the fan according to the tempera ture
of the coo lant .
An auxiliary electric radiator fan * swi tches on and off depending on
coo lant temperature and other vehicle operating conditions.
After you switch the engine off, the auxiliary fan can continue running for up to 10 minut es -even with th e igni tion o ff. It can even
switch o n again later by itself~ & , if
• the temperature of the engine coo lant rises due to the heat
bui ld -up from the engine in the engine compartment, o r
• the engine compartment heats up because the vehic le is parked
in intense sun light.
& WARNING
• To reduce the ri sk of per sonal injury never tou ch the radiator
f a n.
& W AR N ING (continu ed )
• The auxiliary e le ctri c fan i s temperature controlled and can
s w itch on suddenly even when the engine is not running .
• The auxiliary radiator fan swit ches on automatically when the
engine coolant reache s a ce rtain temperature and will con tinue to
run until the coolant t emperatur e drop s. •
Brake fluid
Checking brake fluid level
Th e brake fluid level c an be checked with a quick glance.
Fig . 23 6 En gin e
co mp art m ent : B ra ke
fl uid re servoir
Befo re yo u c heck anything in th e en gin e compar tme nt,
always read and heed all WARNINGS~ & in "Working in
the eng ine compartment" on
page 297 .
Rea d the brake fl uid level from the bra ke fluid reservoir
~ fig . 236. T he b rake fluid leve l must be betwee n the
" M IN " and "MAX" markings.
The brake fluid reservoir is located at the rear parti tion of the engine
compartment on the left side~
page 298. .,_

lffl __ C _h_ e_ c_k _in --== g'-- a_n _d_ f_il _li _n ..:::g:::..- ___________________________________________ _
With certain types of airbag deployment, the battery is discon­
nected from the vehicle electrical system for safety reasons=>&. in
"Repair, care and disposal of the airbags" on
page 226.
Di sc o nnect ing the b attery t ermin als
Some vehic le functions (power window regulators, for example) are
lost if the battery terminals are disconnected. These func tions have
to be relearned after the battery terminals are connected again . To
prevent this, the battery should only be disconnected from the
vehic le electrical system when absolute ly necessary for repairs.
V ehicle s not driven for long period s
If you do not drive your vehicle over a period of several days or
weeks, electrical components are gradually cut back or switched off .
This reduces energy consumption and maintains starting capability
over a longer period =>
page 265.
Take into consideration that when you un lock your vehicle, some
convenience functions, such as the master key remote function or
power seat adjustment, may not be available. The convenience
functions will be availab le again when you turn on the ignition and
start the engine .
Winter oper ation
During the w inter months, battery capacity tends to decrease as
temperatures drop. This is because more power is also consumed
while s tarti ng, an d the headlights, rear wi ndow defogger, etc ., are
used more often.
Avoid unnecessary p ow er consumption, particularly in ci ty traffic or
when trave ling only short distances. Let your authorized Audi dea ler
check the capacity of the vehicle battery before winter sets in
=> page 310. A we ll charged battery wil l not on ly prevent starting
problems when the weather is cold, but wi ll also last longer.
[ i J Tips
If your vehicle is left standing for severa l weeks at extremely low
t empera tures, the vehicle ba ttery should be r emoved and stored where it will not freeze
. This will prevent it from being damaged and
having to be replaced .•
Working on the battery
B e espec ially caref ul when working on or near the battery.
Fi g. 23 7 Lugg age
compartm ent : B attery
The battery is located in the luggage compartment under
the floor. Before you check a nything in the l uggage
com partme nt,
read and heed all WARNINGS=>& .
-Lift the floor by the plastic handle.
Hook t he hand le in to the luggage compartment weather
st rip.
Always heed the safety warnings , when working on the vehicle
ba ttery or the vehicle e lectrical system to prevent injury.

Checking and filling 111111
---------------------------=----
•
The following WARNINGS are very important when
working on the battery:
Always heed the following WARNING SYMBOLS and safety pre­
cautions when working on the battery .
Always wear eye protection.
Battery acid contains sulfuric acid. Always wear
gloves and eye protection.
No
- sparks
- flames
- smoking.
When a battery is charged, it produces hydrogen
gas which is explosive and could cause personal
injury.
Always keep the battery well out of reach of chil ­
dren.
& WARNING
Whenever working on the battery or on the electrical system,
there is the risk of injury, accident and even fire. Read and heed the
following WARNINGS:
• Always wear eye protection. Do not let battery acid or any lead
particles get on your skin or clothing. Shield your eyes. Explosive
gases can cause blindness or other injury.
• Battery acid contains sulfuric acid. Sulfuric acid can cause
blindness and severe burns.
- Always wear gloves and eye protection. Do not tilt the
battery because acid could leak out of the ventilation openings.
- If you get battery acid in your eyes or on your skin, immedi­
ately rinse with cold water for several minutes and get medical
attention.
& WARNING (continued)
-If you should ingest any battery acid, seek medical attention
immediately.
• Do not expose the battery to an open flame, electric sparks or
an open light.
• Do not smoke.
• Do not interchange the positive and negative cables .
• When working on the battery, be sure not to short -circuit the
terminals with tools or other metal objects. This would cause the battery to heat up very quickly, which could lead to damage or
explosion and personal injury.
• When a battery is charged, it produces hydrogen gas which is
explosive and could cause personal injury.
• Always keep the battery well out of the reach of children.
• Before work is done on the electrical system, disconnect the
negative ground cable.
• Before performing any work on the electrical system, switch off
the engine and ignition as well as any electrical equipment. The
negative cable on the battery must be disconnected.
If you are just
going to replace a light bulb, then it is enough to switch off the
lights.
• Before disconnecting the battery, switch off the anti-theft
alarm system! Otherwise you will set off the alarm.
• When disconnecting the battery, first disconnect the negative
cable and then the positive cable.
• Before reconnecting the battery, make sure all electrical
consumers are switched off. Reconnect the positive cable first and
then the negative cable . Never interchange the cables - this could
start a fire!
• Never charge a frozen or a thawed-out battery. It could
explode! If a battery has frozen, then it must be replaced. A
discharged battery can freeze over at 32 °F (0 °CI. .,,_
Vehicle care
I t •