2015 AUDI S4 overheating

22 Instruments and warning/indicator lights
If the symbol II illuminates, the dynam ic
headlight range cont rol is no longer wo rking
properly. Have the system checked and re­
pa ired at your author iz ed Audi dealer.
~O Adaptive Light
Applies to vehicles: with adaptive light
111 Aud i adaptive l ight: defective
If t he indicator lig ht t urns on a nd th is mes­
sage appears, t he re is a ma lfunction in the
adapt ive light system. The headlig hts still
function.
Go to an a uth o rized dea le rship to have the
headlights or the contro l unit for the adapt ive
light repa ired.
~ o Light/rain sensor
Applies to vehicles: with light/rain sensor
£I Automatic headlights/ automatic wipers
defectiv e
If the indicator light t urns on and th is mes­
sage appears, the lig ht/ra in sensor is n ot
f u nctioning cor rectly .
For safety reasons the low beams are turned
on permanent ly w ith the switch in AUTO .
H owever, you can c ontinue to turn the lights
on and off using the light switc h. You can still
con trol a ll funct ions tha t are in depe nden t of
the rai n sensor through the wi ndshi eld wipe r
l eve r.
Contact your author ized Audi dealer as soon
as possible to have the prob lem cor rected .
Q Adaptive dampers
Applies to vehicles: with Audi drive select and adaptive
dampers
H Suspension: System fault!
If t he
H symbol in the disp lay comes on,
there is a malfunction in the adaptive damp ­
e rs . Please go to an authorized Audi dea ler or
qua lified workshop to have the malfu nction
repaired.
I-: Sport differential
Applies to vehicles: with Audi drive select and sport dif­
ferential
Sport differential : System fault!
There is a malfunction with t he sport d iffe ren­
tia l.
D rive to your au thorized A udi dealer immedi ­
ate ly to have the ma lfunction corrected.
Sport differential : Overheating
T he trans missio n tempera ture has inc reased
s ignifica ntly due to t he spor ty d riving manner .
Dr ive in a less sporty ma nner until the tem­
p era ture re tur ns to the normal range and t he
in dica to r li ght switc he s of.
_& WARNING ... -
Co ntac t your author ized Audi dealer or
qu alified wor kshop if the s port differential
i s faulty or malfunct io ning. T he repair
must be perf ormed by t rained personnel
usi ng the co rrect oil in o rder to ensure
safety.
~ Ignition lock
l3 Ignition lock defective
There is a malfunction in the e lectronic igni­
t ion loc k. Please go to a n author ized Audi
dealer or other qualified worksh op to have t he
malfu nction repa ired .
¢ Q Turn signals
Wh eneve r yo u use the left
Ill o r th e r ight 8]
tu rn s ignal, the in dicato r li ght blin ks. W he n
yo u use t he emerge ncy fla she rs, bo th indic a­
tor lights flash.
If one of the turn s igna l light bulbs bu rn o ut,
t h e tur n sig nal w ill bli nk twi ce as fast as no r­
m al. Ca ref ully dr ive to you r a utho rized Aud i
dealer imme diate ly to have the m alfunction
cor rected.

194 Driving and en vironm ent
8_ WARNING
After driving through water, mud, slush,
etc ., the brakes may be slow to take effect
because of wet brake rotors and pads . Dry
the brakes first by braking carefully to re­
store the full braking effect.
(D Note
Vehicle components such as the engine,
transmiss ion, suspension or electrical sys­
tem can be severely damaged by driving
through wate r.
@ Tips
- Check the depth of the water before dr iv­
i ng through it .
- Do not stop the veh icle, dr ive in reverse
or switc h the engine off when driving
t hr ough water .
- Keep in mind that oncoming vehicles
may c reate waves that raise the water
l evel and make it too deep fo r you r vehi­
cle to dr ive through safely.
-
- Avoid dr iving thro ugh salt water because
i t can ca use corrosion.
Catalytic converter
It is very important that your emission con­
trol system (catalytic conv ert er) is function ­
ing properly to ensure that your vehicle is run­
ning in on env ironm entally sound manner.
,,. Always use lead-free gaso line Q page 207,
Fuel supply .
,,. Never run the tank down a ll th e way to emp ­
ty.
,,. Never put too much moto r oil in your engine
Q page 216, ~ Adding engine oil .
,,. Never try to push -or tow -start your ve hicle .
T he cata lytic converter is an eff ic ient "clean­
up" device built in to the exhaust system of
the vehicle . The catalytic converter burns
many of the polluta nts in the exhaust gas be ­
fore they are released into the atmosphe re . The exclus
ive use of unleaded f uel is critica lly
important for the life of the catalytic conv ert­
er and p roper funct ion ing of the eng ine .
A WARNING
=
-The temperature of the exhaust system
is high, both when driving and after stop­
p ing the eng ine .
- Never touch the exhaust tail pipes once
they have become hot. This could result
in burns.
- Do not park or operate the vehicle i n
areas where the hot exhaust system may
come in co ntact with dry grass, brush,
fue l spill or other material wh ich can
cause a fire .
- Do not app ly additional undercoating or
r u stp roofing on or nea r the exhaust
manifold, exhaust pipes, cataly tic con­
ver ter or he at s hields. Dur ing driv ing, the
substance used fo r undercoating could
overheat and cause a fire.
CI) Note
- Be aware tha t just o ne tank filling with
leaded fu el w ill alre ady ser io usly de ­
grade the performance of the cata lytic
converter .
- Do not exceed the cor rect engine oil level
Q poge 216.
-Do not drive until the fuel t ank becomes
comple tely empty . The engine cou ld mis ­
fire . Unburned fuel could also get into
the exhaust system and th is co uld cause
the catalytic converter to overheat.
- Do not turn off the ignition while the ve­
hicle is mov ing.
- Do not contin ue to ope rate your veh icle
under these conditions, as otherwise fuel
can reach the catalyt ic converter. Th is
co uld result in overheating of the con­
verter, requir ing its replacement.
- To assure efficient operation of the Emis -
sion Control System: .,..

218 Check ing and filling
Engine cooling system
Coolant
The engine coolant performs two functions: it
keeps the engine from overheating and it pro ­
tects the engine from freezing in the winter .
The cooling system is sealed and generally re­
quires little attention.
The cooling system has been filled at the fac­
tory with a permanent coolant which does not need to be changed. The coolant consists of a
mixture of specially conditioned water and the
manufacturer's glycol-basedcoolant addi-
tive G13 antifreeze with ant icorrosion addi­
tives (50% for USA models; 60% for Canadian models) . This mixture both assures the neces­
sary frost protection and protects metal com­
ponents in the engine's cooling system from
corrosion and scaling.
It a lso raises the boil­
ing point of the coo lant.
Do not reduce the concentration of the coo l­
ant in the summer by adding plain water .
The
pr opor tion of coolant add itiv e m ust be at
l eas t 50% but not more than 60%
to main­
tain antifree ze protection and cooling efficien­
cy. If the coolant frost protection is too low,
the coolant could freeze and damage the veh i­
cle heating and eng ine cooling system .
For year-round driving, antifree ze is added at
the factory for temperatures down to:
- -31°F(-35°C)USA
- - 40 ° F ( - 40 °C) Canada.
I f you must add coo lant, use a m ixture of wa­
ter and coolant addit ive. M ixing the coolant
addit ive with dist illed water is recommended.
_& WARNING
Before you check anything in the engine
compartment, always read and heed all
WARNINGS
~ &. in Working in the engine
compartment on page 212.
(D 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 especia lly impor­
tant if you live in a reg ion where the win­
ter is extreme ly cold. If necessary, in­
crease the proportion of coolant additive
to 60% .
- When adding coolant additive to your
cooling system, remember :
- We recommend us ing on ly coolant ad­
d itive G12 ++ or G13 for your vehicle.
This coolant addit ive is availab le at a u­
thorized Audi dealers. Other types of
antifreeze can significantly reduce cor­ rosion protection. The resulting corro­
sion can cause a loss of coolant and se­
rious engine damage .
- Do not add any type of radiator leak seal­
ant to your vehicle's engine coolant.
Add ing radiator repa ir flu id may adverse ­
ly affect the function and performance of
your cooling system and could resu lt in
damage not covered by your New Veh icle
Limited Warranty.
Checking the engine coolant level
The engine coolant level can be checked with
a quick glance.
F ig . 1 85 Engine compar tmen t: Cover on the coo la n t
expans io n t ank
.,. Before you check anything in the engine
compa rtment,
alwa ys read and h eed all
W ARNING S ~ ,& in Working in the engine
compartment on page 212.
.,. Park your vehicle on a level surface .
.,. Turn off the ignition.
.,. Read the engine coolant level from the coo l­
ant expansion tank
c:> fig . 185, c:> page 214,
fig . 182.
With a cold engine, the coolant Iii>-

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,...., ..,., ,....,
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 illus­
tration
<=> page 214.
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 level is too low, the warning
light in the Auto-Check System <=>
page 17 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 rec­
ommend 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 cool­
ing system should be inspected immediately
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.
A WARNING
The cooling system is under pressure and
can get very hot. Reduce the risk of scald­
ing from hot coolant by following these
steps.
- Turn
off the engine and allow it to cool
down.
- Protect your face, hands and arms from escaping fluid and steam by covering the
cap with a large, thick rag .
- Turn the cap slowly and very carefully in
a counter-clockwise direction while ap­
plying light, downward pressure on the
top of the cap .
- To avoid being burned, do not spill anti­
freeze or coolant on the exhaust system
Checking and filling 219
or hot engine parts. Under certain condi­
tions, the ethylene glycol in engine cool­
ant can catch fire.
([) Note
Do not add any type of radiator leak seal­
ant to your vehicle's engine coolant. Add- ing radiator repair fluid may adversely af­
fect the function and performance of your
cooling system and could result in damage
not covered by your New Vehicle limited
Warranty .
Adding coolant
Be very careful when adding engine coolant.
Before you check anything in the engine com­
partment ,
always read and heed all WARN­
INGS <=>
A in Working in the engine compart­
ment on page 212 .
Requirement: There must be a residual
amount of coolant in the expansion tank <=>(D.
.,. Turn
off the engine.
.,. Let the engine cool down.
.,. Place a thick rag over the coolant expansion
tank
<=> page 218, fig . 185 and carefully turn
the cap counter-clockwise
<=> .&_ .
.,. Add coolant mixed in the correct ratio
<=> page 218, Coolant up to the MAX mark­
ing.
.,. Make sure that the fluid level remains sta-
ble. Add more coolant if necessary.
.,. Twist the cap on again
tightly.
Replacement engine coolant must conform to
exact specifications <=>
page 218, Coolant.
We recommend using only coolant additive
G12 ++, G13 or in an emergency G12 +. Do
not
use a different additive. In an emergency use
plain water until you can get the correct addi­
tive and can restore the correct ratio. This
should be done 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 . .,.
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~ Unscrew the va lve stem from the s pare tire .
~ Screw the tire filler hose from the compres­
sor firm ly onto the valv e of the spare tire.
~ In se rt the p lug from the compress or into a
socket of the vehicle¢
page 66.
~ Switc h the compressor on .
~ Let the compressor run until the valu e speci­
fied on the tire pressure label is reached ¢
page 234, fig . 190. Sw itch the compres­
so r off afte r runn ing for 12 minutes at the
most -danger of overhea ting!
A WARNING
The compressor and the tire filler hose can
become extremely hot while they are run­
ning -danger of burns!
(D Note
Switch the compressor off after running
for 12 minutes at the most -danger of
overheating! Allow the compressor to cool
down for a few minutes before you use it
again.
Changing a wheel
Before changing a wheel
Observe the following precautions for your
own and your passenger' s safety when chang­
ing a wheel .
~ After you experience a tire fa ilure, pu ll the
ca r well away from moving traffic and try to
r e ach
level gro und before yo u stop ¢ LI)..
~ All p assengers sho uld leave the car and
move to a safe loca tion (for instance, beh ind
the guardrai l) ¢
A .
~ Engage the parking brake to prevent your
vehicle from ro lling un intentionally ¢
A.
~ Shift into 1st gear on vehicles with manua l
transmission, o r move the
selector lever to
the P po sition
on veh icles with au toma tic
t ransmission .
~ If you are tow ing a tra ile r: u nhi tch the trail­
er from your veh icle.
~ T ake the jack ¢ page 260 and the spare tire
¢ page 261 out of the luggage compart ­
ment.
What do I do now? 263
A WARNING
You or your passengers could be injured
while c hanging a wheel if you do not fo l­
low these safety precaut ions:
- If you have a flat tire, move a safe d is­
tance off the road . T urn off the engine,
tur n the eme rg ency flashers on and use
other wa rn in g devices to a le rt othe r mo­
torists.
- Ma ke sur e that passengers wait in a safe
p lace away from the vehicle and well
away from the ro ad and traffic.
- T o help prevent the vehicle from moving
suddenly and possib ly sli pping off the
j a ck, alw ay s fu lly se t the par king br ake
an d block the wheel d iagonally opposi te
the whee l be ing changed w ith the fol d­
ing chocks or other objects. When one
front wheel is lifted off the ground, plac­ ing the Automatic Transmission in "P"
(Park) will
not prevent the vehicle from
moving .
- Before you change a wheel, be sure the
grou nd is level and firm. I f necessary,
use a sturdy board unde r the jack .
- Always sto re the vehicle tool kit, the
jack* and the replaced tire in the luggage compa rtment
¢page 132.
(D Note
If you are changing the whee l on a steep
i ncline, use a rock or s imilar object to
block the opposite whee l to prevent the
vehicle from moving.
(D Tips
Obey all laws.
Changing a wheel
When you change a wheel , follow these­
quence described below step-by-step and in
exactly that order .
l. Remove the decorative wheel cover* or
-
the wheel bolt caps* . For more details see..,.
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