2014 AUDI S4 engine overheat

202 Trailer towing
Tire pressure
When towing a trailer, inflate the tires of your
vehicle to the cold tire pressure listed under
"Full load" on the label located on the driver's
side B-pillar (visible when the door is open).
Inflate trailer tires to trailer and tire manufac ­
turers' specifications.
Lights
The headlight settings should be checked with
the trailer attached before driving off. Check
to make sure both vehicle and trailer lights
are working properly.
Safety chains
Be sure trailer safety chains are properly con­
nected from the trailer to the hitch on the ve­
hicle. Leave enough slack in the chains to per­
mit turning corners. When you install safety
chains, make sure they will not drag on the road when you are driving.
The chains should cross under the trailer
tongue to prevent it from dropping in case of
separation from the hitch.
Driving instructions
Driving with a trailer always requires extra
care and consideration.
To obtain the best possible handling of vehicle
and trailer, please note the following:
.,. Do not tow a loaded trailer when your car it­
self is not loaded.
.,. Be especially careful when passing other
vehicles.
.,. Observe speed limits .
.,. Do not drive at the maximum permissible
speed.
.,. Always apply brakes early.
.,. Monitor the temperature gauge.
Weight distribution
Towing a loaded trailer with an empty car re­
sults in a highly unstable distribution of
weight . If this cannot be avoided, drive at very
low speeds only to avoid the risk of losing
steering control. A "balanced" rig is easier
to operate and con­
trol. This means that the tow vehicle should be loaded to the extent possible and permissi­
ble, while keeping the trailer as light as possi­
ble under the circumstances. Whenever possi­
ble, transfer some cargo to the luggage com ­
partment of the tow vehicle while observing
tongue load requirements and vehicle loading
considerations.
Speed
The higher the speed, the more difficult it be­
comes for the driver to control the rig. Do not
drive at the maximum permissible speed. Re­
duce your speed even more if load, weather or
wind conditions are unfavorable -particularly
when going downhill.
Reduce vehicle speed
immediately if the trail­
er shows the slightest sign of swaying .
Do not
try to stop the swaying by accelerating.
Observe speed limits. In some areas, speeds
for vehicles towing trailers are lower than for
regular vehicles .
Always apply brakes early. When driving downhill, shift into a lower gear to use the en ­
gine braking effect to slow the vehicle . Use of
the brakes alone can cause them to overheat
and fail.
Coolant temperature
The coolant temperature gauge c> page 10
must be observed carefully . If the needle
moves close to the upper end of the scale, re­
duce speed immediately and/or turn off the
air conditioner.
If the coolant temperature warning light •
in the instrument cluster starts flashing, pull
off the road, stop and let the engine
idle for
about two minutes to prevent heat build-up .
_& WARNING
Anyone not properly restrained in a mov­
ing vehicle is at a much greater risk in an
accident. Never let anyone ride in your car
who is not properly wearing the restraints
provided by Audi.
-

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
qu ires 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-based coolant addi-
tive G13 antifreeze with anticorros ion 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 also raises the boil ­
ing point of the coolant.
Do not reduce the concentration of the coo l­
ant in the summer by adding plain water .
The
proportion of coolant additive must be at
least 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 vehi ­
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 mixture of wa­
ter and coolant addit ive. Mixing the coolant
additive with distilled water is recommended.
& WARNING
Before you check anything in the engine
compartment, always read and heed all
WARNINGS
c::;, .&. in Working in the engine
compartment on page 214.
(D Note
- Before winter sets in, have the coolant
checked to see if the coolant additive in
Checkin g and fillin g 221
your vehicle is sufficient to meet the cli ­
mate conditions. This is especia lly impor­
tant if you live in a region where the win­
ter is extremely co ld. If necessary, in­
crease the proportion of coolant additive
to 60% .
- When adding coolant additive to your
cooling system, remember :
- We recommend using only coolant ad­
ditive G12++ or G13 for your vehicle .
This coolant additive is available at au­
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.
Adding radiator repair fluid may adverse­
ly affect the function and performance of
your cooling system and could result 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.
Fig. 185 En gin e compar tment: Cover on the coo la n t
expansio n tan k
"' Before you check anything in the engine
compa rtme nt,
always read and heed all
WARNINGS c::;, .&, in Working in the engine
compartment on page 214.
"'Park your vehicle on a level su rface .
.,. Turn off the ignition .
.,. Read the engine coolant level from the cool­
ant expansion tank
i=> fig . 185, c::;, page 216,
fig . 182. With a cold engine, the coolant Iii>

222 Check ing and filling
level should be between the "MIN" and
"MAX" markings. When the engine is warm,
the leve l may be slightly above the "MAX"
marking .
The location of the coolant expansion tank
can be seen in the engine compartment illus­
tration
c:> page 216.
To obtain an accurate reading, the engine must be switched
off.
The expansion tank in you r vehicle is equipped
with an e lectric coolant level sensor.
When the coolant level is too low, the warning light in the Auto-Check System
c:> page 17will
b link until you add coo lant and the level has
been restored to no rma l. Even though there is
an electric coolant level sensor, we still rec ­
ommend you check the coolant leve l from
time to time.
Coolant loss
Coolant loss may indicate a leak in the cool ing
system. In the event of coolant loss, the cool ­
ing system should be inspected immediately
by your authorized A udi dealer.
It is not
enough merely to add coolant.
I n a sealed system, losses can occur only if
the boiling point of the coolant is exceeded as
a result of overheat ing.
A WARNING
The cooling system is unde r 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
dow n.
- Protect yo ur 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 wh ile ap­
plying light, downward pressure on the
top of the cap .
- To avoid be ing burned, do not spill ant i­
freeze or coolant on the exhaust system
'
or hot engine parts. Under certa in cond i­
tions, the ethylene glycol in engine coo l­
ant can catch fire.
(D Note
Do not a dd any type of radiator leak sea l­
ant to your veh icle's engine coolant. Add ­
i ng radiator repa ir fl uid may adverse ly af­
fect the funct ion and performance of your
cooling system and could result in damage
not covered by your New Veh icle L imited
War ranty .
Adding coolant
Be very careful when adding engine coolant.
Before you check anyth ing in the eng ine com­
partment, always read and heed all WARN­
INGS
c:> A in Working in the engine compart­
ment on page 214 .
Requirement: There m ust be a res idual
amount of coo lant in the expans ion tank
c:> (]) .
.,.. Turn off the eng ine .
.,.. Let the engin e cool down.
.,.. Place a thick rag over the coo lant expansion
tank
c:> page 221 , fig. 185 and carefully turn
the cap counter-clockwise
c:> .&_ .
.,.. Add coo lant m ixed in the correct rat io
c:> page 221, Coolant up to the MAX ma rk­
ing.
.,.. Mak e s ure t hat the fl uid leve l remains sta-
b le. Add more coo lant if necessary.
.,.. Twist the cap on again
tightly .
Replacement engine coo lant must confo rm to
ex act spec ific at ions
c:> page 221, Coolant.
We recommend using only coolant add it ive
G12 ++, G13 or i n an emergency G 12+. Do
not
use a different add it ive. In an emergen cy use
plain wa ter until yo u can ge t the correct addi­
tive and can restore t he correct ratio. This
sho uld be done as soon as possib le .
If you have los t a cons iderab le amount o f
coolant, the n you sho uld add cold ant ifree ze
and co ld wate r on ly when the engine is cold.
Always use
n ew engine coo la nt w hen refilling . .,.

~ 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 64.
~ 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. Switch 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 252 and the spare tire
¢ page 253 out of the luggage compart ­
ment.
What do I do now? 255
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 full y 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 134.
(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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