engine overheat AUDI S8 2016 User Guide

Checking and Filling
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 222.
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 15 will il­
luminate 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 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 re­
sult of overheating.
_& WARNING
The cooling system is under pressure and can
get very hot. Reduce the risk of scalding from
hot coolant by following these steps.
- Turn off the engine and allow it to cool
down.
- Protect your face, hands and arms from es­
caping 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 applying
light, downward pressure on the top of the
cap.
- To avoid being burned, do not spill anti­
freeze or coolant on the exhaust system or
hot engine parts. Under certain conditions,
the ethylene glycol in engine coolant can
catch fire.
228
(D Note
Do not add any type of radiator leak sealant
to your vehicle's engine coolant. Adding radia­
tor repair fluid may adversely affect the func­
tion 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 compart­
ment,
always read and heed all WARNINGS
¢.& in Working in the engine compartment on
page 220 .
.. 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 22 7, fig. 201 and carefully twist
the cap counter-clockwise ¢&, .
.,. Add coolant mixed in the correct ratio
r::!> page 22 7, Coolant up to the MAX marking.
.. Make sure that the fluid level remains stable.
Add more coolant if necessary .
.. Twist the cap on again
tightly.
Replacement engine coolant must conform to ex­
act specifications ¢
page 22 7, 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 wa­
ter until you can get the correct additive and can
restore the correct ratio. This should be done as
soon as possible.
If you have lost a considerable amount of cool­
ant, then you should add cold antifreeze and cold
water only when the engine is cold.
Always use
new engine coolant when refilling.
Do not fill coolant above the "MAX" mark . Excess
coolant will be forced out through the pressure
relief valve in the cap when the engine becomes
hot.
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