2023 HYUNDAI SONATA engine coolant

08
8 -7
While operating your vehicle: •
Note any changes in the sound of the
exhaust or any smell of exhaust fumes
in the vehicle.
• Check for vibrations in the steering
wheel. Notice if there is any increased
steering effort or looseness in the
steering wheel, or change in its
straight-ahead position.
• Notice if your vehicle constantly turns
slightly or “pulls” to one side when
traveling on smooth, level road.
• When stopping, listen and check for
unusual sounds, pulling to one side,
increased brake pedal travel or “hard-
to-push” brake pedal.
• If any slipping or changes in the
operation of your transmission occurs,
check the transmission fluid level.
• Check the automatic transmission P
(Park) function.
• Check the parking brake.
• Check for fluid leaks under your
vehicle (water dripping from the air
conditioning system during or after use is normal).
At least monthly: • Check coolant level in the engine
coolant reservoir.
• Check the operation of all exterior
lights, including the brake lights, turn
signals and hazard warning flashers.
• Check the inflation pressures of all
tires including the spare for tires that
are worn, show uneven wear, or are damaged.
• Check for loose wheel lug nuts. At least twice a year:
(i.e., every Spring and Autumn) •
Check radiator, heater and air
conditioning hoses for leaks or damage.
• Check windshield washer spray and
wiper operation. Clean wiper blades
with a clean cloth dampened with
washer a fluid.
• Check headlamp alignment.
• Check muffler, exhaust pipes, shields and clamps.
• Check the seat belts for wear and function.
At least once a year: • Clean body and door drain holes.
• Lubricate door hinges and hood hinges.
• Lubricate door and hood locks and
latches.
• Lubricate door rubber weather strips.
• Lubricate door checker.
• Check the air conditioning system.
• Inspect and lubricate automatic
transmission linkage and controls.
• Clean the battery and terminals.
• Check the brake fluid level.

Maintenance
8-10
Maintenance Schedule (Smartstream G1.6 T-GDI) (CONT)R : Replace A : Add S : Service I : Inspect L : Lubricate r : RotateDESCRIPTIONKILOMETERS X 1000
8 16 24 32 40 48 56 64 72 80 88 96 104 112 120 128 136 144 152 160
MONTHS 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120Fuel Tank, Fuel Filler Cap,
Canister, Vapor Hose I I I I I
Fuel Tank Air Filter I I I I I
Fuel Filter I I I I I
Fuel Lines, Hoses and Connections I I I I I
Air Cleaner Filter I R I R I R I R I R Brake fluid I I R I I R I I R ISpark plugs Replace every 72,000 km
Engine Coolant First, replace 192,000 km or 120 months.
After that, replace every 48,000 km or 24 months

Maintenance
8-14
Maintenance Schedule (Smartstream G2.5 GDI) (CONT)R : Replace A : Add S : Service I : Inspect L : Lubricate r : RotateDESCRIPTIONKILOMETERS X 1000
8 16 24 32 40 48 56 64 72 80 88 96 104 112 120 128 136 144 152 160
MONTHS 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120Fuel Tank, Fuel Filler Cap,
Canister, Vapor Hose I I I I I
Fuel Tank Air Filter I I I I I Fuel Filter I I I I I
Fuel Lines, Hoses and Connections I I I I I
Air Cleaner Filter I R I R I R I R I R Brake fluid I I R I I R I I R ISpark plugs Replace every 160,000 km or 84 months
Engine Coolant First, replace 192,000 km or 120 months.
After that, replace every 48,000 km or 24 months

Maintenance
8-18
Maintenance Schedule (Smartstream G2.5 T-GDI) (CONT)R : Replace A : Add S : Service I : Inspect L : Lubricate r : RotateDESCRIPTIONKILOMETERS X 1000
8 16 24 32 40 48 56 64 72 80 88 96 104 112 120 128 136 144 152 160
MONTHS 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120Fuel Tank, Fuel Filler Cap,
Canister, Vapor Hose I I I I I
Fuel Tank Air Filter I I I I I Fuel Filter I I I I I
Fuel Lines, Hoses and Connections I I I I I
Air Cleaner Filter I R I R I R I R I R Brake fluid I I R I I R I I R ISpark plugs Replace every 160,000 km or 84 months
Engine Coolant First, replace 192,000 km or 120 months.
After that, replace every 48,000 km or 24 months

Maintenance
8-20
Engine Oil and Filter
The engine oil and filter should be
changed at the intervals specified in the
maintenance schedule.
Drive Belts
Inspect all drive belts for evidence
of cuts, cracks, excessive wear or oil
saturation and replace if necessary. Drive
belts should be checked periodically
for proper tension and adjusted as
necessary.
Fuel Filter
A clogged-up fuel filter may limit the
vehicle driving speed, damage the
emission system, and cause the hard
starting. When a considerable amount
of foreign substances are accumulated
in the fuel tank, the fuel filter should be
replaced.
Upon installing a new fuel filter, operate
the engine for several minutes, and
check the connections for any leakages.
Fuel filters should be installed by an
authorized HYUNDAI dealer.
Fuel Lines, Fuel Hoses and Connections
Check the fuel lines, fuel hoses and
connections for leakage and damage.
Have an authorized HYUNDAI dealer
replace any damaged or leaking parts
immediately.
Vapor Hose and Fuel Filler Cap
The vapor hose and fuel filler cap should
be inspected at those intervals specified
in the maintenance schedule. Make sure
a new vapor hose or fuel filler cap is
correctly replaced.
Air Cleaner Filter
A genuine HYUNDAI air cleaner filter
is recommended when the filter is
replaced.
Spark Plugs
Make sure to install new spark plugs of
the correct heat range.
Cooling System
Check cooling system components, such
as radiator, coolant reservoir, hoses and
connections for leakage and damage.
Replace any damaged parts.
ExpLanation of SCHEDULED maintEnanCE itEmS

08
8-21
Engine Coolant
The coolant should be changed at the
intervals specified in the maintenance schedule.
Automatic Transmission Fluid
Automatic Transmission Fluid should
be replaced by an authorized HYUNDAI
dealer at the intervals specified in the
maintenance schedule.
Information
Automatic transmission fluid color is red
when new. As the vehicle is driven, the automatic transmission fluid will begin to look
darker. This is a normal condition and you
should not judge the need to replace the
fluid based upon the changed color.
NOTICE
The use of a non-specified fluid could
result in transmission malfunction
and failure. Use only the specified
automatic transmission fluid (refer
to “Recommended Lubricants and
Capacities” in chapter 2).
Brake Hoses and Lines
Visually check for proper installation,
chafing, cracks, deterioration and any
leakage. Replace any deteriorated or
damaged parts immediately.
Brake Fluid
Check the brake fluid level in the brake
fluid reservoir. The level should be
between the MIN and the MAX marks
on the side of the reservoir. Use only
hydraulic brake fluid conforming to DOT
4 specification.
Parking Brake
Inspect the parking brake system
including the parking brake pedal and cables.
Dual clutch transmission fluid (if equipped)
Inspect the dual clutch transmission fluid
according to the maintenance schedule.
Brake Discs, Pads, Calipers and
Rotors
Check the pads for excessive wear, discs
for run out and wear, and calipers for
fluid leakage.
Exhaust Pipe and Muffler
Visually inspect the exhaust pipes,
muffler and hangers for cracks,
deterioration, or damage. Start
the engine and listen carefully for
any exhaust gas leakage. Tighten
connections or replace parts as
necessary.

Maintenance
8-26
The high-pressure cooling system has a
reservoir filled with year-round antifreeze
coolant. The reservoir is filled at the
factory.
Check the antifreeze protection and
coolant level at least once a year, at
the beginning of the winter season and
before traveling to a colder climate.
NOTICE
• 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.
• Do not drive with no engine coolant.
It may cause water pump failure and
engine seizure, etc.
Checking the Engine Coolant
Level
ODN8089004
Check the condition and connections
of all cooling system hoses and
heater hoses. Replace any swollen or
deteriorated hoses.
The coolant level should be filled
between the F and the L marks on the
side of the coolant reservoir when the engine is cool. If the coolant level is low, add enough
distilled (deionized) water to bring the
level to the F mark, but do not overfill. If
frequent additions are required, see an
authorized HYUNDAI dealer for a cooling
system inspection.
Recommended engine coolant • When adding coolant, use only
distilled (deionized) water for your
vehicle and never mix hard water in
the coolant filled at the factory.
• An improper coolant mixture can
result in severe malfunction or engine damage.
• The engine in your vehicle has
aluminum engine parts and must be
protected by an ethylene-glycol with
phosphate based coolant to prevent
corrosion and freezing.
• Do not use alcohol or methanol
coolant or mix them with the specified
coolant.
• Do not use a solution that contains
more than 60% antifreeze or less than
35% antifreeze, which would reduce
the effectiveness of the solution.
EnginE CooLant

08
8-27
For mixing percentage, refer to the
following table:
Ambient
Temperature Mixture Percentage
(volume)
Antifreeze Water
-15°C (5°F) 35 65
-25°C (-13°F) 40 60
-35°C (-31°F) 50 50
-45°C (-49°F) 60 40
Information
If in doubt about the mix ratio, a 50%
water and 50% antifreeze mix is the
easiest to mix together as it will be the same quantity of each. It is suitable to
use for most temperature ranges of -35°C
(-31°F) and higher.
WARNING
Make sure the coolant cap is properly
closed after refilling coolant. Otherwise
the engine could be overheated while driving.
„„Engine room front view
ODN8089052L
1. Check if the coolant cap label is straight in front.
2. Make sure that the tiny protrusions inside the coolant cap is securely
interlocked.
ODN8089044
WARNING
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 thick towel around it, and turn it
counterclockwise slowly to the first
stop. Step back while the pressure is
released from the cooling system. When
you are sure all the pressure has been
released, press down on the cap, using
a thick towel, and continue turning
counterclockwise to remove it.