2023 HYUNDAI SONATA engine coolant

While Driving
6-154
Winter Precautions
Use high quality ethylene glycol
coolant
Your vehicle is delivered with high
quality ethylene glycol coolant in the
cooling system. It is the only type of
coolant that should be used because it
helps prevent corrosion in the cooling
system, lubricates the water pump and
prevents freezing. Be sure to replace or
replenish your coolant in accordance
with the maintenance schedule in
chapter 8. Before winter, have your
coolant tested to assure that its freezing
point is sufficient for the temperatures
anticipated during the winter.
Change to "winter weight" oil if necessary
In some climates it is recommended that
a lower viscosity "winter weight" oil be
used during cold weather. See chapter 8
for recommendations. If you aren't sure
what weight oil you should use, consult
an authorized HYUNDAI dealer.
Check battery and cables
Winter puts additional burdens on the
battery system. Visually inspect the
battery and cables as described in
chapter 8. The level of charge in your
battery can be checked by an authorized
HYUNDAI dealer or a service station.Check spark plugs and ignition
system
Inspect your spark plugs as described in
chapter 8 and replace them if necessary. Also check all ignition wiring and
components to be sure they are not
cracked, worn or damaged in any way.
Use approved window washer anti-
freeze in system
To keep the water in the window washer
system from freezing, add an approved
window washer anti-freeze solution in
accordance with instructions on the
container. Window washer anti-freeze is
available from an authorized HYUNDAI
dealer and most auto parts outlets. Do
not use engine coolant or other types
of antifreeze as these may damage the
paint finish.
Do not let your parking brake freeze
Under some conditions your parking
brake can freeze in the engaged position.
This is most likely to happen when
there is an accumulation of snow or
ice around or near the rear brakes or
if the brakes are wet. If there is a risk
the parking brake may freeze, apply
it only temporarily while you put the
gear selector lever in P and block the
rear wheels so the car cannot roll. Then
release the parking brake.

Emergency Situations
7-6
If your temperature gauge indicates
overheating, you experience a loss of
power, or hear loud pinging or knocking,
the engine may be overheating. If this
happens, you should:
1. Pull off the road and stop as soon as it
is safe to do so.
2. Place the shift button in P (Park) and set the parking brake. If the air
conditioning is ON, turn it OFF.
3. If engine coolant is running out under the vehicle or steam is coming out
from the hood, stop the engine. Do
not open the hood until the coolant
has stopped running or the steaming
has stopped. If there is no visible
loss of engine coolant and no steam,
leave the engine running and check
to be sure the engine cooling fan is
operating. If the fan is not running,
turn the engine off.
WARNING
While the engine is running,
keep hands, clothing and tools
away from the moving parts
such as the cooling fan and
drive belt to prevent serious
injury.
4. Check for coolant leaking from the
radiator, hoses or under the vehicle. (If the air conditioning had been in use, it
is normal for cold water to be draining
from it when you stop.)
5. If engine coolant is leaking out, stop the engine immediately and call the
nearest authorized HYUNDAI dealer
for assistance.
If the engIne overheats

07
7-7
WARNING
Your vehicle is equipped
with a pressurized coolant
reserve tank. NEVER remove
the engine coolant reservoir
tank/radiator cap or the drain plug while the engine and
radiator are HOT. Hot coolant
and steam may blow out under
pressure, causing serious
injury.
Turn the engine off and wait until the
engine cools down. Use extreme care
when removing the engine coolant
reservoir tank/radiator cap. Wrap
a towel or thick rag around it, and
turn it counterclockwise slowly to
release some of the pressure from the
system. Step back while the pressure is
released.
When you are sure all the pressure has
been released, continue turning the cap
counterclockwise to remove it.
6. If you cannot find the cause of the overheating, wait until the engine
temperature has returned to normal.
Then, if coolant has been lost,
carefully add coolant to the reservoir
to bring the fluid level in the reservoir
up to the halfway mark.
7. Proceed with caution, keeping alert
for further signs of overheating. If
overheating happens again, call
an authorized HYUNDAI dealer for
assistance.
NOTICE
• Serious loss of coolant indicates a
leak in the cooling system and we
recommend the system be checked
by an authorized HYUNDAI dealer.
• When the engine overheats from
low engine coolant, suddenly adding
engine coolant may cause cracks
in the engine. To prevent damage,
add engine coolant slowly in small
quantities.
• If there is overheating, park your
vehicle in a safe place and do not
turn off the engine until the cooling
fan stops. The engine might get stuck
due to sudden increase of water
temperature.
• Turn off the engine if the cooling fan
does not rotate.

07
7-21
BasIC trouBleshootIng guIDe
SYMPTOM
PROBABLE CAUSE
Starter won’t function
Engine turns over but will not start
Engine misfires
Engine overheats
Engine stops while driving driving
Fuel consumption is excessive
Brake pedal is spongy
Braking power is insufficient
Steering wheel is heavy
Steering wheel shakes
Steering wheel pulls to one side while driving
Vehicle pulls to one side while braking
Tire wear is abnormal
Charge warning light comes on while driving
Wipers, horn or lights won’t funciton
Battery discharge is excessive
Engine overheating O
Low fuel level O O
Fuel lines clogged O O
Fuel pump defective O O
Strainer clogged O O
Rich mixture O O O Water intrusion into fuel O O O
Coolant leakage OHigh idle speed O
Engine oil insufficient or defective O O
Battery fluid shortage O O
Battery discharged O O O
Battery terminal poor contact O O
Starter or ignition switch malfunction O
Ignition timing incorrect O O O Spark plugs deteriorated O O Spark plugs defective O

Engine Compartment .................................................................................... 8-3
Maintenance Services ................................................................................... 8-5
Owner’s Responsibility ............................................................................................ 8-5
Owner Maintenance Precautions ............................................................................ 8-5
Owner Maintenance ...................................................................................... 8-6
Owner Maintenance Schedule ................................................................................ 8-6
Scheduled Maintenance Services ................................................................ 8-8
Maintenance Schedule (Smartstream G1.6 T-GDI) ................................................8-8
Maintenance Schedule (Smartstream G2.5 GDI) ..................................................8-12
Maintenance Schedule (Smartstream G2.5 T-GDI) ...............................................8-16
Explanation of Scheduled Maintenance Items ..........................................8-20
Engine Oil ..................................................................................................... 8-23
Checking the Engine Oil Level ............................................................................... 8-23
Checking the Engine Oil and Filter ....................................................................... 8-25
Engine Coolant ............................................................................................. 8-26
Checking the Engine Coolant Level ...................................................................... 8-26
Changing Engine Coolant ...................................................................................... 8-28
Brake Fluid .................................................................................................... 8-29
Checking the Brake Fluid Level ............................................................................. 8-29
Washer Fluid ................................................................................................. 8-30
Checking the Washer Fluid Level .......................................................................... 8-30
Air Cleaner ..................................................................................................... 8-31
Filter Replacement .................................................................................................. 8-31
Climate Control Air Filter ............................................................................. 8-33
Filter Inspection...................................................................................................... 8-33
Filter Replacement ................................................................................................. 8-33
Wiper Blades ................................................................................................ 8-34
Blade Inspection .................................................................................................... 8-34
Blade Replacement ................................................................................................ 8-34
Battery .......................................................................................................... 8-36
For Best Battery Service ........................................................................................ 8-36
Battery Recharging ................................................................................................ 8-37
Reset Features ........................................................................................................ 8-37
8. Maintenance
8

8-3
08
1. Engine coolant reservoir
2. Brake fluid reservoir
3. Air cleaner
4. Engine oil dipstick 5. Engine oil filler cap
6. Windshield washer fluid reservoir
7.
Fuse box
8. Battery
EnginE CompartmEnt
„„Smartstream G1.6 T-GDI
„„Smartstream G2.5 GDI
The actual engine room in the vehicle may differ from the illustration.ODN8089103/ ODN8N080008L

8-4
Maintenance
„„Smartstream G2.5 T-GDI
The actual engine room in the vehicle may differ from the illustration.ODN8N080009L
1. Engine coolant reservoir
2. Brake fluid reservoir
3. Air cleaner
4. Engine oil dipstick 5. Engine oil filler cap
6. Windshield washer fluid reservoir
7.
Fuse box
8. Battery

Maintenance
8-6
WARNING
Performing maintenance work on a
vehicle can be dangerous. If you lack
sufficient knowledge and experience or
the proper tools and equipment to do
the work, have it done by an authorized
HYUNDAI dealer.
ALWAYS follow these precautions for
performing maintenance work: • Park your vehicle on level ground,
move the shift button into the P
(Park) position, place the ignition
switch in the LOCK/OFF position.
• Block the tires (front and back) to
prevent the vehicle from moving.
Remove loose clothing or jewelry
that can become entangled in
moving parts.
• If you must run the engine during
maintenance, do so out doors or in
an area with plenty of ventilation.
• Keep flames, sparks, or smoking
materials away from the battery and
fuel-related parts. The following lists are vehicle checks and
inspections that should be performed
by the owner or an authorized HYUNDAI
dealer at the frequencies indicated to
help ensure safe, dependable operation
of your vehicle.
Any adverse conditions should be
brought to the attention of your dealer as soon as possible.
These Owner Maintenance vehicle
checks are generally not covered by
warranties and you may be charged for
labor, parts and lubricants used.
Owner Maintenance Schedule
When you stop for fuel: •
Check the coolant level in the engine
coolant reservoir.
• Check the windshield washer fluid
level.
• Check the for low or under-inflated
tires.
WARNING
Be careful when checking your engine
coolant level when the engine is hot.
This may result in coolant being blown
out of the opening and cause serious
burns and other injuries.
ownEr maintEnanCE