engine overheat AUDI A4 CABRIOLET 2009 Owners Manual

The instrument cluster illuminates whenever you switch on the igni­
tion with the
vehicle headlights off. The instrument cluster illumina ­
tion dims automatically as the daylight begins to fade away. It goes
out completely when the outside light is very dim. The reason for
this is to remind you to turn on the headlights when the light condi­
tions become poor. •
Engine coolant temperature gauge
The engine coolant gauge~ page 12, fig. 2 G) only works when the
ignition is on . To prevent damage to your engine, please note the
following important points:
Engine cold
As long as the needle remains at the left end of the gauge, the
engine still has not reached its operating temperature . Avoid high
engine speeds, heavy engine loads and heavy throttle.
Normal temperature
When the engine has reached its operating temperature, the needle
will move into the middle of the gauge and remain there. If the
engine is working hard at high outside temperatures, the needle
may turn further to the right . This is no cause for concern as long as
the
- F-warning light in the instrument cluster does not illuminate.
When the
-L warning light starts to flash, this can mean one of two
things: either the coolant
temperature is too high, or the coolant
level is too low~ page 31.
_& WARNING
• Always observe the warning in ~ page 242, "Engine compart­
ment" before opening the engine hood and checking the engine
coolant level.
• Never open the engine hood if you see or hear steam, or if you
see engine coolant dripping from the engine compartment. You
Controls and equip ­
ment
Instruments and warning/indicator lights
& WARNING (continued)
could burn yourself. Let the engine cool off first so that you cannot
hear or see any steam or engine coolant.
0 Note
• Mounting additional lights or accessories in front of the air inlets
reduces the cooling effect of the radiator. At high outside tempera­
tures or high engine load, the engine could overheat.
• The front spoiler has been designed to properly distribute the
cooling air when the vehicle is moving. If the spoiler is damaged,
this could reduce the cooling effect and the engine could then over­
heat. Ask your authorized Audi dealer for assistance. •
Tachometer (engine rev counter)
The tachometer indicates the engine RPM (revolutions per
minutes).
The tachometer ®~ page 12, fig. 2 is the left one of the two large
clock -type displays.
The engine turns at a speed
1,000 times the single digit in the
display, e.g. if the needle points at the "2", the engine turns at
2,000 RPM.
If the engine RPMs drop below 1,500, you should downshift to the
next lower gear. The red area at the end of the scale indicates
maximum permissible engine RPMs after the break-in period.
Before reaching this area, you should either shift into the next
higher gear or ease your foot off the accelerator pedal.
0 Note
The tachometer needle should not move into the red range. If it
does, then only for a very short period of time. You could damage
your engine by driving at high RPM! _.

Inst rum ents and warnin g/indi cato r li ghts
M alfu nction message
If there is a malfunction somewhere in the ins trument cluster, dE F
will appear in the trip odometer and will stay on. Contact your
authorized Audi dea ler to have the prob lem corrected.
Im mob ilizer
Each time you switch on the ignition, the data stored in the vehicle
key are e lectronically scanned to verify that key data and vehicle
data match. If a non -coded or a defective vehic le key is used, the
word
S A FE wi ll appear and remain lit in the upper (trip) odometer
display . If this happens, the vehicle cannot be started=>
page 49. •
Fuel gauge
The fuel gauge works only when the ignition is on .
When the needle reaches the red area, the warning light in the instrument cluster wil l illuminate =>
page 33 [). This means you
have approx imately 2.4 gallons (9 liters) of fuel left in the tank.
Time
t o refu el!
The total tank capacity of your vehicle is listed in=> page 314.
0 Note
Never run the tank completely dry! An irregular supply of fuel can
cause engine misfiring and fuel could enter into the exhaust
system. The catalytic converter could then overheat and be
damaged. •
[ CHE CK] button
You can perform different functions with this button.
I S2YY
0
Fig. 6 C HECK butto n in
th e ins tru men t c lu ste r
The [ CHECK] button performs the following functions:
S wi tch ing on t he cl ock and odome ter
With the ignition is switched off, the odometer and digital clock with
date disp lay can be switched on for a few seconds by pressing the
[CHECK] button=> fig. 6.
Sta rtin g t he A uto-Che ck se qu ence
The Auto-Check system=> page 28 consistently monitors certain
individual functions and componen ts of the vehicle when the igni­
tion is turned on and when the vehicle is moving.
With the ignition switched on, you can start the" Auto-Check
sequence" by pressing the [
CHECK I button. You can perform an
Auto -Check sequence both when the vehic le is at a standstill and
the ignition is switched on or when the veh ic le is mov ing not faster
than 3 mph (5 km/h).
Ca lling up th e dri ver inform ation
When a first priority symbol starts to flash=> page 28 or when a
defective light bulb=>
page 35, has been detected, you can press
the
! CHECK] button to display the driver information. For example:
S witch off engine and chec k oi l le vel

On the road -_______________ ____,
0 Note
Do not stop the engine immediately after hard or extended driving.
Keep the engine running for approximately two minutes to prevent
excessive heat build-up. •
Parking brake
Parking brake
When the parking brake is set, it prevents the vehicle from
rolling away unintentionally.
Setting the parking brake
Fig . 137 Center
console: Parking brake
set
- Pull the parking brake lever all the way up.
Releasing the parking brake
- Pull the parking brake lever up slightly
and press the
release button at the same time=:> fig. 137 -arrow-.
- Keep the release button pressed and lower the parking
brake =>
&-
Contro ls and eq uip­
ment
If you should drive off with the parking brake still set, a warning tone
will sound and the following will appear in the instrument cluster to
remind you to release the parking brake:
Parking brake set
The parking brake warning comes on only after you have driven for longer than 3 seconds and faster than 5 mph (5 km/h).
The parking brake warning light Brake (Canada:
{(j))) illuminates
when the parking brake is set and you switch on the ignition .
& WARNING
Always release the parking brake completely. A partially engaged
brake will overheat the rear brakes, reduce their effectiveness and
cause excessive wear. This could lead to brake failure and an acci­
dent.
0 Note
Only after the vehicle has come to complete stop, should you firmly
set the parking brake and either move the gearshift lever into 1st.
gear (manual transmission) or move the selector lever into P (Auto ­
matic transmission). •
Parking
To prevent a parked vehicle from rolling away, there are a
few things you should do.
When you park your vehicle, do the following:
- Stop the vehicle using the brake pedal.
- Set the parking brake firmly.
- Move the selector lever into the
P position =:> &.
~ehicle care Technical data

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Driving off
When driving off, always be sure to keep road conditions in mind as
you accelerate. If one drive wheel spins because it is on a surface
with less grip, gradually increase the pressure on the accelerator
pedal until the car starts to move. The wheel less able to transfer
power spins.
Overheating of brakes
To prevent the disc brake of the braked wheel from overheating if
subjected to excessive loads, the EDL cuts out temporarily. The
vehicle remains operational and behaves in the same way as a
vehicle without EDL.
As soon as the brake has cooled down, EDL switches on again auto­ matically.
& WARNING
• When accelerating on slippery surfaces, such as on ice or snow,
always be careful when depressing the accelerator pedal. Even
with the EDL working, the drive wheels can spin and reduce your ability to control your car. -Risk of crash!
• The increased safety afforded by EDL does not mean that you
can take safety risks. Always adapt your driving style to the road
conditions and traffic situation.
[ i] Tips
If a fault occurs in the ABS, the EDL is also not functioning. This is
indicated by the ABS warning light=>
page 20. •
Anti-Slip Regulation System (ASR)
The Anti-Slip Regulation System prevents the driven
wheels from spinning when the car is accelerating.
General notes
The Anti-Slip Regulation System (ASR) is integrated in the electronic
stabilization program (ESP). When the vehicle starts up and acceler­
ates, the wheels are prevented from spinning by adjusting the
engine power to match the amount of grip available from the road
surface.
How the system works
ASR performs automatically, i.e. without the driver's intervention.
With the aid of the ABS sensors=>
page 276, ASR monitors the
speed of the driven wheels. If the wheels start to spin, the engine
power is reduced automatically until the tires find enough grip to
lock onto the road surface. The system is active across the entire
speed range.
Th e ASR works in conjunction with the ABS. If a malfunction should
occur in the ABS, the ASR will also be out of action.
& WARNING
The increased safety afforded by ASR does not mean that you can
take safety risks. Always adapt your driving style to the road
conditions and traffic situation.
[ i] Tips
To ensure that the ASR works properly, all four wheels must be fitted
with identical tires Any differences in rolling radius of the tires can
cause the system to reduce engine power when this is not desired.
S ee also =>
page 279, "New tires and replacing tires and wheels". •

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& WARNING (continued)
• Do not "ride the brakes" by resting your foot on the pedal when
you do not intend to brake. This may cause the brakes to overheat, premature wear and increased stopping distance.
• Under certain climatic and operating conditions such as
passing through water, driving in heavy rain or after washing the
vehicle, the effectiveness of the brakes can be reduced. In winter,
ice can accumulate on the brake pads, linings, discs and drums .
Cautiously apply brakes for a test. Brakes will dry and ice coatings
will be cleaned off after a few cautious brake applications .
• Driving for an extended period of time on salt-covered roads
without using your brakes can also affect braking efficiency. Clean
off accumulated salt coating from brake discs and pads with a few
cautious brake applications.
• If you damage the front spoiler, or if you install a different
spoiler, be sure the air flow to the front brakes is not obstructed.
Otherwise the brake system could overheat reducing the effective ­
ness of the entire brake system.
• Failure of one brake circuit will impair the braking capability
resulting in an increased stopping distance. Avoid driving the
vehicle and have it towed to the nearest Audi dealer or qualified
workshop. u
Brake booster
The brake booster adds extra braking power.
The brake booster works with vacuum pressure which is created
only when the engine is running~ &.
& WARNING
• Never let the vehicle roll to a stop with the engine shut off.
• If the brake booster is not working, for example when towing
your vehicle, or because the brake booster has somehow been
& WARNING (continued)
damaged, the brake pedal must be pressed considerably harder to
make up for the lack of booster assistance. •
Functioning of Anti-Lock Brake System (ABS)
ABS prevents the wheels from locking up under braking.
The ABS contributes effectively to vehicle control since it prevents
the wheels from
locking when the brakes are applied. This means
that the vehicle remains steerable and is less likely to skid.
With ABS you do not need to pump the brake. Just hold the brake
pedal down.
However , do not expect that the ABS shortens braking distance
under
all circumstances. When driving on gravel or on newly fallen
snow on top of icy surfaces, braking distance may be even longer,
therefore, under these circumstances, it is especially important that
you drive slowly and with great care.
How the ABS system works
An automatic check is made when a speed of about 4 mph (6 km/h)
is reached. When this happens, a pumping noise can be heard.
If an individual wheel begins to rotate too slowly in relation to
vehicle speed and tends to lock, the ABS automatically reduces brake pressure to prevent that wheel from locking.
This automatic adjustment process will cause a
slight vibration of
the brake pedal and some noises to alert you that vehicle speed
must be adapted to existing road and traffic conditions.
& WARNING
Although the ABS is very effective, always remember that braking
capability is limited by tire traction . Always adjust your driving
speed according to the road and traffic conditions. Do not let the .,_

& WARNING (c ont in u ed)
ext ra sa fe ty a fforded by the ABS tempt you into t ak in g ex tr a risks .
The ABS cannot overco me th e law s of ph ysics.
[ i J Tips
• If ABS is not funct ioning properly, a warning light will come on.
See
=> page 20.
• If a fau lt occurs in the ABS, the EDL is also not funct ion ing . This
is indicated by the ABS warning light.
Brake assistant
T he brake assistant is designed to achieve the optimum
braking effect.
The brake assistant helps to increase the effective braking power
and thus to achieve a shorter stopping distance . If the driver
presses the brake pedal very quick ly, the brake assistant automati ­
cally boosts the braking force to the maximum level, up to the point
where the anti -lock brake function (ABS) intervenes to stop the
wheels from locking. You should then keep the brake pedal pressed until the vehicle has braked to the required speed. The brake assis­
tant switches itself off as soon as you re lease the brake peda l.
The brake assistant will not be operative if there is a malfunction in
the ABS .
& WARNING
Please remembe r that the accident risk always in cre a se s if you
dri ve to o fa st, e spe cially in cor ner s o r on a slipp ery road , or if you
follow th e vehicle ahead of you too clos ely. An increased a ccident
ri sk ca nnot be comp en sa ted even b y the brake assista nt , s o
alwa ys maintain a safe spe ed . •
Controls and equip­ ment Safety first Vehicle operation
Int
ellig ent tec hnol ogy
Servotronic® -advanced power
steering system
The power steering systems uses the power of the
running engine to allow precise steering with little effort.
The advanced Servotronic ® power steering system senses the road
speed and electronically adjusts power assistance to provide
comfortab le and safe steering response exactly matched to the
vehicle speed.
Power steering will not work if the engine is off. As a result, the
steering whee l wil l be hard to turn .
The power steering fluid level is checked during the schedu led
maintenance services.
0 Note
If there is an electronic ma lfunction, servotronic will still function
like a conventional power steer ing system, providing a constant
steering support force that is no longer proportionate to the vehicle
speed. This is most noticeable when tu rning the steering whee l at
low speeds (for examp le when parking), -more effort wil l be
requi red than usual.
• Be aware of the different than usual steering response and
adjust you r steering force accordingly .
• Have the problem checked and set right by an Audi dealer as
soon as possible .
[ i J Tips
• When the engi ne is running, never hold the steering whee l
turned all the way to the right or to the left for longer than 15
seconds. The power steering pu mp will overheat the hydraulic fluid
if you keep holding the steering wheel turned a ll the way. This is
likely to damage the power stee ring system.
~
Vehicle care Do-it-yourself service Technical data

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New brake pads
Remember that new brake pads do not have a full braking
effec t during the first 250 miles (400 kilometers) after they
are installed .
New brake pads have to be "burn ished in" before they have optimal
grab =>& .
During the break -in period, you shou ld avoid putting severe loads
on the brakes . Severe loads include, for examp le, sudden hard
braking, in particular at very high speeds or, for example, on moun ­
tain passes.
& WARNING
Ne w brake p ad s don't h ave the bes t sto pp in g po we r and mu st b e
"brok en-in " durin g the initial 100 to 1 50 m il es ( 150 to 200 kil ome ­
t e rs) of norm al cit y dri ving . Y o u can com pensat e for thi s by
p re ss ing the br ake p ed al more firm ly. Th is also appli es later w he n
n ew pad s a re in sta lled.
:J
Catalytic converter
It is very important that your emission control system
(catalytic converter) is functioning properly to ensure that
y o ur vehicle is running in an environmentally sound
manner.
- Always use lead-free gasoline=> page 244, "Fuel supply".
- Never run the tank down a ll the way to empty.
- Never put too much motor o il in your engine =>
page 255,
"Adding eng ine oi l 'l:::r.11
•
- Neve r try to push -or tow -s ta rt yo ur vehic le.
The catalytic converter is an efficient "clean-up" device built into the
exhaust system of the vehicle. The catalytic converter burns many
of the po llutants in the exhaust gas before they are released into the
atmosphere.
The exc lusive use of unleaded fue l is critica lly important for the l ife
of the cata lytic converter and proper functioning of the engine.
& WARNING
• Do not p ark or op erate th e veh icle in are as w here the h ot
ex hau st sys tem m ay come in co ntac t w ith dr y gr ass, brush , fuel
s pill or other mater ial which can cau se a fire .
• Do not apply a dditi ona l u nder coating or ru stpr oofing on or
n ea r the exhau st m anifold , exhau st pipe s, ca ta lytic conv ert er or
h eat shie ld s. Dur in g d riving , the sub sta nce use d fo r und ercoa ting
coul d ove rhea t and cause a fire .
0 Note
• Be aware that just one tank filling with leaded fue l wi ll already
seriously degrade the performance of the catalytic converter.
• Do not exceed the correct engine oi l level =>
page 255.
• Do not drive until the fuel tank becomes comp letely empty . The
engine cou ld misfire. Unburned fuel could also get into the exhaust
system and this could cause the catalytic conver ter to overheat .
• Do not turn off the ignition while the vehicle is moving.
• Do not con tinue to operate your vehicle under these conditions,
as otherwise fuel can reach the cata lytic converter . This cou ld result
in overheating of the converter, requiring its rep lacement .
• To assure eff icient operation of the Em ission Control System:
- Have your vehicle maintained properly and in accordance with
the service recommendations in your Warranty
& Maintenance
booklet. •

-Dri
ving and environm ent --=---------------
one half . Never drive faster than the posted speed limit and weather
conditions permit .•
Reducing unnecessary idling
Even when your car is just idling it burns up fuel.
- Shut the eng ine off when you are not driving the vehicle.
- Do not warm up the vehicle by letting the engine run at
idle.
It makes sense to shut off the engine in traffic jams, when waiting
for trains to pass at rai lroad crossings, or at traffic lights that have
long waits on red. Turning the engine off for just 30 -40 seconds
saves more fuel than is burned s tarting the engine again .
It takes a long time for the engine to warm up fully when it is
running at idle. However, wear and noxious emissions are especially
high when the engine is warming up. So you should drive away as
soon as you star t the engine and avoid running at high rpms while
the engine is still warming up.
0 Note
Do not leave engine idling unattended after starting . If warning
lights should come on to indicate improper operation, they would
go unheeded. Extended id ling also produces heat, which could
resu lt in overheating or other damage to the veh icle or other
property .•
Regu1ar maintenance
A badly tuned engine unnecessarily wastes a lo t of fuel.
- Have your ve hicle serviced at regular intervals . By having your vehicle regularly serviced by an Audi dealer helps to
ensure that it runs properly and economical
ly . The condit ion of yo ur
vehic le not only affects its safety and abi lity to hold its va lue, it also
affects
fuel consumpt ion .
C heck your oil each time you fill your tank .
The amount of oil used is related to engine load and speed.
I t is norma l for the oil consumption of a new engine to reach its
lowest va lue after a certain mi leage has been driven.
You must drive your vehicle about 3,000 miles (5,000 kilometers) be fore you can properly assess oil consumption .
This also applies to fuel consumption and engine output .
0 Note
• Have your vehicle maintained properly and in accordance with
the service recommendations in your Warranty
& Maintenance
booklet. Lack of proper maintenance as well as improper use of the
vehic le wi ll impai r the function of the em ission control system and
cou ld lead to damage.
• Do no t alter or re move any component of the Emiss ion Contro l
System unless approved by the manufacturer.
• Do not alte r or remove any device, such as heat shields,
switches, ignition wires, valves, which are designed to protect your
vehic le's Emission Control System and other important veh icle
components. •
Fewer short trips
Fu el consumption will alw ays be rela tively high o n short
trips.
- Try to avo id d riving short dista nces wi th a cold engine. _,

-Tr
aile r t owing ---=--------------
W eig ht dis tri buti on
Towing a loaded trailer with an empty car resu lts in a high ly
unstable distribution of weight . If this cannot be avoided drive at
ve ry low speeds only to avoid the risk of los ing steering control.
A "ba lanced" rig is easier to operate and control. This means that
the tow vehicle should be loaded to the extent possible and permis ­
sib le whi le keeping the trailer as light as possib le under the circum ­
stances. Whenever possible, transfer some cargo to the luggage
compartment of the tow vehicle while observing tongue load
requirements and vehicle loading considerations .
Speed
The higher the speed, the more difficult it becomes for the driver to
contro l the rig . Do not drive at the maximum permissible speed.
Reduce your speed even more under unfavorable load, weather or
wind condi tions -particularly when going downhill.
Reduce vehicle speed
imm ed iately if the trailer shows the slightest
sign of swaying.
Do not try to stop the s waying by a ccelerating .
Observe speed limits. In some areas speeds for vehic les towing
trai lers are lower than for regular vehicles.
Always app ly brakes early. When driving downhill, shift into lower
gear to use the engine braking effect to slow down the vehicle. Use
of the brakes alone can cause them to overheat and fail.
C oo lan t tem pe ra ture
The coolant temperature gauge~ page 73 must be observed care ­
fully. If the needle moves close to the upper end of the scale, reduce
speed immediately and/or switch off the air conditioner.
If the coolant temperature warning light in the instrument cluster
starts flashing -~- , pul l off the road, stop and let the engine
idle for
about two minutes to prevent heat build -up .
& WARNING
An yone not prop erl y r estr ained in a mo ving ve hic le is at a much
gre ater ri sk in an accident. N ever let an yone rid e in your car who
is not p roperl y wearing the r estraint s pro vid ed by Audi.
c
Trailer towing tips
Important to know
Your vehicle handles differently when towing a trai ler because of
the additional weight and weight distribution . Safety, performance
and economy will great ly depend on how carefu lly you load your
trai ler and operate your rig.
Before you actually tow your trailer, practice turn ing, stopping and
backing up in an area away from traffic. Keep practicing unti l you
have comp letely become familiar with the way your vehicle -trailer
combination behaves and responds .
Backing up is difficu lt and requires practice. Backing up with a
trailer genera lly requires s teering action opposite of that when
backing up your vehic le without a trailer.
Maintain a greater distance between you r vehicle and the one in
front of you. You will need more room to stop.
To compensate for the trailer, you wi ll need a larger than normal
turning radius .
When passing, remember that you cannot accelerate as fast as you nor mally wou ld because of the added load . Make sure yo u have
enough room to pass. After passing, allow plenty of room for your
trai ler before changing lanes again .
Avo id jerky starts, sharp turns o r rapid lane changes.

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0 Note
• Before winter sets in, have the coolant checked to see if the
coolant additive in your vehicle is sufficient to meet the climate
conditions. This is especially important if you live in a region where
the winter is extremely cold . If necessary, increase the proportion of
coolant additive to 60% .
• When adding coolant additive to your cooling system,
remember:
-We recommend using only coolant additive G12+ + (check the
label) for your vehicle. This coolant additive is available at autho­
rized Audi dealers. Other types of antifreeze can significantly
reduce corrosion protection . The 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 could result
in damage not
covered by your New Vehicle Limited Warranty. •
Checking the engine coolant level
The engine coolant level can be checked with a quick
glance.
Fig . 202 Engine
compartment: Coolant
expansion tank
Before you check anything in the engine compartment,
always read and heed all WARNINGS~ & in "Working in
the engine compartment" on
page 250.
Turn off the ignition.
- Let the eng ine cool down.
Place a thick rag over the coolant expansion tank
~ fig. 202 and carefully twist the cap counter-clockwise
~& .
Read the engine coolant level in the open coolant expan­
sion tank~ fig. 202. With a cold engine, the coolant level
should be between the "min" and "max" markings. When
the engine is warm, the level may be slightly above the
"max" marking .
The location of the coolant expansion tank can be seen in the
engine compartment illustration=>
page 252.
To obtain an accurate reading , the engine must be switched off .
The expansion tank in your vehicle is equipped with an electric
coolant level sensor.
When the coolant l evel is too low, the warning light in the Auto ­
Check System :::::,
page 31 will blink until you add coolant and the
level has been restored to normal. Even though there is an electric
coolant level sensor, we still recommend you check the coolant level
from time to time .
Coolant loss
Coolant loss may indicate a leak in the cooling system. In the event
of coolant loss, the cooling system should be inspected immedi ­
ately by your authorized Audi dealer . It is not enough merely to add
coolant.
In a
sealed system, losses can occur only if the boiling point of the
coolant is exceeded as a result of overheating. ..,.