Get Checking and Filling -> Cooling system Guide for Audi A5 4 Door Third Generation (2025-2026)

Checking and Filling

Changing engine oil

– Drain the oil into a container designed for

this purpose that is large enough to hold the

full amount of oil in your engine.

Audi recommends having the oil changed at an

authorized Audi dealer or authorized Audi Serv-

ice Facility.

– Engine oil is poisonous. Always store out of

reach of children.

Observe the safety precautions ðpage 237, Gen-

eral information.

– Prolonged contact of used engine oil with

the skin may cause skin damage. Always

wash oil off immediately with soap and wa-

ter to protect your skin.

The engine oil must be changed at the intervals

specified in the Warranty & Maintenance Book-

let. This is very important because the lubrication

function of the oil gradually declines during regu-

lar vehicle operation.

Note

Do not mix any additives with the engine oil.

Additives may cause engine damage that is

not covered by your New Vehicle Limited War-

ranty.

The engine oil should be changed more frequent-

ly under certain circumstances. Have the oil

changed more frequently if you often drive short

distances, your vehicle is predominantly in stop-

and-go traffic situations, is in very dusty environ-

ments, or is operated for long periods of time in

temperatures below zero.

For the sake of the environment

– Before changing the engine oil, make sure

you can dispose of the used engine oil cor-

rectly.

Cleansing additives in the oil make fresh oil ap-

pear darker after the engine has run briefly. This

is normal and no reason to change the engine oil

more frequently than recommended.

– Engine oil must always be disposed of cor-

rectly. Do not dump it in the yard, in the for-

est, or in open water, river channels, or sew-

ers.

– Have your used engine oil recycled by bring-

ing it to a used oil collection site or contact

a gas station.

Because correctly disposing of engine oil is diffi-

cult and special tools and technical knowledge

are needed for an oil change, Audi recommends

having your engine oil changed by an authorized

Audi dealer or authorized Audi Service Facility.

Cooling system

If you change the engine oil yourself, please note

the following important information:

Coolant

The engine cooling system is filled with a mixture

of purified water and coolant additive at the fac-

tory. This coolant must not be not changed.

WARNING

If you change the engine oil on the vehicle

yourself, the following precautions must be

followed:

The coolant level is monitored using the  indi-

cator light. However, you should occasionally

check the coolant level.

– Wear protective eyewear.

– Due to the risk of scalding, allow the engine

to cool down sufficiently.

Messages

The following messages may appear, depending

on the vehicle equipment:

– Maintain enough distance when you are re-

moving the oil drain plug. While doing this,

keep your forearm parallel to the ground to

reduce the risk of hot oil dripping down your

arm.

 Turn off engine and check coolant level. See

owner's manual

The coolant level is too low.



244

Checking and Filling

Do not continue driving and turn off the ignition.

Check the coolant level ðpage 246.

for the climate. This is especially important

when driving in colder climates.

– If the G12evo coolant additive is not availa-

ble in an emergency, do not add any other

additive. You could damage the engine. If

this happens, only use distilled water and

restore the correct mixture ratio with the

specified coolant additive as soon as possi-

ble.

– If the coolant level is too low, add coolant

ðpage 246. Only continue driving once the in-

dicator light turns off.

 Coolant temperature: too high. Please let

engine run while vehicle is stationary

Let the engine run at idle for a few minutes to

cool off, until the indicator light turns off.

– Only refill with new coolant.

– Radiator sealant must not be mixed with

the coolant.

– If the indicator light does not turn off, do not

continue driving the vehicle. See an authorized

Audi dealer or authorized Audi Service Facility

for assistance.

– You can continue driving if the permitted

G12evo coolant additive was not added.

However, go to an authorized Audi dealer or

authorized Audi Service Facility immediately

to have the coolant replaced to reduce the

risk of engine damage.

 Coolant system: malfunction! Please turn

off engine

Do not continue driving, shut off the engine, and

turn off the ignition. See an authorized Audi deal-

er or authorized Audi Service Facility for assis-

tance.

– Due to the risk of engine damage, the cool-

ing system should only be refilled by an au-

thorized Audi dealer or authorized Audi

Service Facility. An authorized Audi dealer or

authorized Audi Service Facility can also pro-

vide you with important information about

the recommended coolant additive.

Coolant additive

The coolant additive is made of anti-freezing and

corrosion protection agents. Only add the follow-

ing coolant additives mixed with distilled water.

Coolant additive

G12evo

Specification

TL 774 L

The amount of coolant additive that needs to be

mixed with water depends on the climate where

the vehicle will be operated. If the coolant addi-

tive percentage is too low, the coolant can freeze

and damage the engine.

Coolant

additive

Freeze protec-

tion

Warm

regions

min. 40%

max. 45%

min. -13 °F

(-25 °C)

Cold

regions

min. 50%

max. 55%

max. -40 °F

(-40 °C)

Note

– Before the start of winter, have an author-

ized Audi dealer or authorized Audi Service

Facility check if the coolant additive in your

vehicle matches the percentage appropriate

245

Checking and Filling

be between the markings 2 when the engine is

cold. When the engine is warm it can be slight-

ly above the upper marking.

Checking coolant

►

If you must add coolant, use a mixture of water

and coolant additive. Audi recommends mixing

the coolant additive with distilled water.

►

Allow the engine to cool ð

Place a large, thick towel on the coolant expan-

sion tank cap.

►

Push the release button 1 ðfig. 163 on the

cap and carefully turn it to the left until you

Fig. 163 Engine compartment - coolant expansion tank

feel resistance ð

Push the release button again and remove the

cap completely.

Requirement for adding coolant: there must be

a residual amount of coolant in the expansion

(diagram):

cover with release button;

coolant expan-

►

sion tank markings( 4-cylinder engine)

tank ð

►

Add the correct mixture ratio of coolant

ðpage 245 up to the upper marking

ðfig. 163.

►

Make sure that the fluid level remains stable.

Add more coolant if necessary.

Turn the cap to the right to tighten it until you

feel resistance a second time.

Fig. 164 Coolant expansion tank markings (6-cylinder en-

gine)

Checking the coolant level/adding coolant

(2)

Applies to: vehicles with coolant expansion tank in the ple-

num chamber

Observe the safety precautions ðpage 237, Gen-

eral information.

Depending on the version of the engine, the cool-

ant expansion tank will be located in the engine

compartment ðpage 246, Checking the coolant

level/adding coolant (1) or in the plenum cham-

ber under a cover ðpage 246, Checking the cool-

ant level/adding coolant (2):

In vehicles with a 6-cylinder engine, the coolant

expansion tank is located under a cover in the

plenum chamber ðpage 240, fig. 160.

►

Park the vehicle on a level surface.

►

Turn off the ignition.

►

Allow the engine to cool ð

Open the hood ðpage 239.

Remove the cover that is located under the

windshield wiper on the front passenger's side.

Place a large, thick towel on the coolant expan-

sion tank cap.

Checking the coolant level/adding coolant

(1)

Applies to: vehicles with coolant expansion tank in the engine

compartment

►

In vehicles with a 4-cylinder engine, the coolant

expansion tank is located in the engine compart-

ment ðpage 240, fig. 160.

Push the release button 1 ðfig. 163 on the

cap and carefully turn it to the left until you

feel resistance ð

►

Park the vehicle on a level surface.

►

Push the release button again and remove the

cap completely.

There is a float located in the coolant expansion

tank. Read the coolant level using the coolant

level float ðfig. 164. When the engine is cold,

the float must be located between the MIN

►

Turn off the ignition.

Open the hood ðpage 239.

Check the coolant level in the coolant expan-

sion tank ðpage 240, fig. 160 using the outer

markings 2 ðfig. 163. The coolant level must

►



246

Checking and Filling

marking and the edge of the filler opening

(MAX) on the coolant expansion tank

ðfig. 164. When the engine is warm, the float

can also be slightly above MAX.

If the coolant level is correct, turn the cap to

the right to tighten it until you feel resistance a

second time, and then reinstall the cover below

the windshield wiper.

If you must add coolant, use a mixture of water

and coolant additive. Audi recommends mixing

the coolant additive with distilled water.

Requirement for adding coolant: there must be

a residual amount of coolant in the expansion

Note

Coolant loss that results in the coolant expan-

sion tank becoming nearly empty primarily in-

dicates that there are significant leaks in the

cooling system, which can lead to further

damage.

►

– Do not add coolant if the expansion tank is

empty. Air could enter the cooling system

and increase the risk of damage. If this is

the case, do not continue driving. See an au-

thorized Audi dealer or authorized Audi

Service Facility for assistance.

►

– If there is any coolant remaining, add addi-

tional coolant. Drive to an authorized Audi

dealer or authorized Audi Service Facility

immediately to have the malfunction cor-

rected. If the  indicator light turns on

again, do not continue driving and turn off

the ignition. See an authorized Audi dealer

or authorized Audi Service Facility for assis-

tance.

tank ð

Add coolant in the correct mixture ratio

ðpage 245 until the float is positioned at the

edge of the filler opening on the coolant expan-

sion tank (= MAX) ðfig. 164.

Make sure that the fluid level remains stable.

Add more coolant if necessary.

Turn the cap to the right to tighten it until you

feel resistance a second time, and then rein-

stall the cover below the windshield wiper.

►

– If there is too much coolant in the expan-

sion tank after adding coolant, drive to an

authorized Audi dealer or authorized Audi

Service Facility as soon as possible to have

the coolant level corrected.

WARNING

– The engine/motor compartment in any vehi-

cle is a potentially dangerous area. Shut off

the engine, turn off the ignition, and allow

the engine to cool before working in the en-

gine compartment. Always follow the infor-

mation found in ðpage 237, General infor-

mation.

– Using non-distilled water increases the risk

of engine damage. Its chemical components

may cause significant corrosion damage in

the engine.

– If you had to add a large amount of non-dis-

tilled water (more than 0.5 liter), then im-

mediately drive to an authorized Audi dealer

or authorized Audi Service Facility to have

the coolant changed.

– Never open the hood if you can see or hear

steam or coolant escaping from the engine

compartment. This increases the risk of

burns. The cooling system is under pressure.

When you no longer see or hear steam or

coolant escaping, you may open the engine

compartment with caution.

Brake fluid

– When working in the engine compartment,

remember that the radiator fan can turn on

even if the ignition is turned off, which in-

creases the risk of injury.

– Coolant additive and coolant can be danger-

ous to your health. For this reason, store the

coolant in the original container and away

from children. There is a risk of poisoning.

Fig. 165 Engine compartment: cap on brake fluid reservoir



247

Checking and Filling -> Cooling system for Your Audi A5 4 Door Third Generation (2025-2026)

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