2018 Hyundai Sonata fuel cap

Maintenance
7-16
I : Inspect : Inspect and if necessary, adjust, correct, clean or replace.
R : Replace or change.
*
3: Fuel filter & Fuel tank air filter are considered to be maintenance free\
but periodic inspection is recommended for this mainte-nance schedule depends on fuel quality. If there are some important safety matters like fuel flow restriction, surging, loss of
power, hard starting problem, etc. replace the fuel filter immediately regardless of maintenance schedule a\
nd consult an
authorized HYUNDAI dealer for details.
Normal Maintenance Schedule (Theta 2.4 GDI) (CONT)
Months1224364860728496108120132144156168180
Miles×1,0007.51522.53037.54552.56067.57582.59097.5105112.5
Km×1,0001224364860728496108120132144156168180
Brake lines, hoses and connectionsIIIIIIIIIIIIIII
Disc brakes and padsIIIIIIIIIIIIIII
Driveshaft and bootsIIIIIIIIIIIIIII
Suspension mounting boltsIIIIIIIIIIIIIII
Air conditioner refrigerantIIIIIIIIIIIIIII
Air conditioner compressorIIIIIIIIIIIIIII
Exhaust pipe and mufflerIIIIIIIIIIIIIII
Automatic transaxle fluid (if equipped)No check, No service required
Steering gear rack, linkage and bootsIIIIIIIIIIIIIII
Vapor hose, fuel filler cap and fuel tankIIIIIII
Fuel tank air filter *3IIIIIII
Fuel filter *3IIIIIII
Fuel lines, hoses and connectionsIII
MAINTENANCE INTERVALS
MAINTENANCE
ITEM

7-20
Maintenance
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Engine Oil and Filter
The engine oil and filter should be
changed at the intervals specified in
the maintenance schedule. If the car
is being driven in severe conditions,
more frequent oil and filter changes
are required.
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 peri-
odically for proper tension and
adjusted as necessary.
Fuel Filter
A clogged filter can limit the speed at
which the vehicle may be driven,
damage the emission system and
cause multiple issues such as hard
starting. If an excessive amount of
foreign matter accumulates in the
fuel tank, the filter may require
replacement more frequently. After
installing a new filter, run the engine
for several minutes, and check for
leaks at the connections. 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 dam-
age. Have an authorized HYUNDAI
dealer replace any damaged or leak-
ing parts immediately.
Vapor Hose and Fuel Filler
Cap
The vapor hose and fuel filler cap
should be inspected at those inter-
vals 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.

7-42
Maintenance
Check Tire Inflation Pressure
Check your tires, including the spare
tire, once a month or more.
How to check
Use a good quality tire pressure
gauge to check tire pressure. You
can not tell if your tires are properly
inflated simply by looking at them.
Radial tires may look properly inflat-
ed when they are under-inflated.
Remove the valve cap from the tire
valve stem. Press the tire gauge firm-
ly onto the valve to get a pressure
measurement. If the cold tire inflation
pressure matches the recommended
pressure on the tire and loading
information label, no further adjust-
ment is necessary. If the pressure is
low, add air until you reach the rec-
ommended pressure. Make sure to
put the valve caps back on the valve
stems. Without the valve cap, dirt or
moisture could get into the valve
core and cause air leakage. If a valve
cap is missing, install a new one as
soon as possible.If you overfill the tire, release air by
pushing on the metal stem in the
center of the tire valve. Recheck the
tire pressure with the tire gauge. Be
sure to put the valve caps back on
the valve stems. Without the valve
cap, dirt or moisture could get into
the valve core and cause air leakage.
If a valve cap is missing, install a new
one as soon as possible.
Under-inflation results in
excessive wear, poor handling
and reduced fuel economy.
Wheel deformation is also
possible. Keep your tire pres-
sures at the proper levels. If a
tire frequently needs refilling,
have it checked by an author-
ized HYUNDAI dealer.
Over-inflation produces a
harsh ride, excessive wear at
the center of the tire tread,
and a greater possibility of
damage from road hazards.
CAUTION

7-50
Maintenance
Tire Terminology and
Definitions
Air Pressure
The amount of air inside the tire
pressing outward on the tire. Air
pressure is expressed in pounds per
square inch (psi) or kilopascal (kPa).
Accessory Weight
This means the combined weight of
optional accessories. Some exam-
ples of optional accessories are
automatic transmission, power
seats, and air conditioning.
Aspect Ratio
The relationship of a tire’s height to
its width.
Belt
A rubber coated layer of cords that is
located between the plies and the
tread. Cords may be made from steel
or other reinforcing materials.
Bead
The tire bead contains steel wires
wrapped by steel cords that hold the
tire onto the rim.
Bias Ply Tire
A pneumatic tire in which the plies
are laid at alternate angles less than
90 degrees to the centerline of the
tread.
Cold Tire Pressure
The amount of air pressure in a tire,
measured in pounds per square inch
(psi) or kilopascals (kPa) before a tire
has built up heat from driving.
Curb Weight
This means the weight of a motor
vehicle with standard and optional
equipment including the maximum
capacity of fuel, oil and coolant, but
without passengers and cargo.
DOT Markings
A code molded into the sidewall of a
tire signifying that the tire is in com-
pliance with the U.S. Department of
Transportation motor vehicle safety
standards. The DOT code includes
the Tire Identification Number (TIN),
an alphanumeric designator which
can also identify the tire manufactur-
er, production plant, brand and date
of production.

7-85
7
Maintenance
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The emission control system of your
vehicle is covered by a written limited
warranty. Please see the warranty
information contained in the Owner’s
Handbook & Warranty Information
booklet in your vehicle.
Your vehicle is equipped with an
emission control system to meet all
applicable emission regulations.
There are three emission control
systems, as follows.
(1) Crankcase emission control sys-
tem
(2) Evaporative emission control sys- tem
(3) Exhaust emission control system
In order to assure the proper function
of the emission control systems, it is
recommended that you have your
vehicle inspected and maintained by
an authorized HYUNDAI dealer in
accordance with the maintenance
schedule in this manual.1. Crankcase Emission Control System
The positive crankcase ventilation
system is employed to prevent air
pollution caused by blow-by gases
being emitted from the crankcase.
This system supplies fresh filtered air
to the crankcase through the air
intake hose. Inside the crankcase,
the fresh air mixes with blow-by
gases, which then pass through the
PCV valve into the induction system.
2. Evaporative Emission ControlSystem Including Onboard
Refueling Vapor Recovery
(ORVR)
The Evaporative Emission Control
System is designed to prevent fuel
vapors from escaping into the atmos-
phere. The ORVR system is
designed to allow the vapors from
the fuel tank to be loaded into a can-
ister while refueling at the gas sta-
tion, preventing the escape of fuel
vapors into the atmosphere.
For the Inspection and
Maintenance Test (With Electronic
Stability Control (ESC) system)
To prevent the vehicle from
misfiring during dynamome-
ter testing, turn the Electronic
Stability Control (ESC) sys-
tem off by pressing the ESC
switch (ESC OFF light illumi-
nated).
After dynamometer testing is
completed, turn the ESC sys-
tem back on by pressing the
ESC switch again.
CAUTION

I-4
Emission Control System ...............................................7-85Crankcase Emission Control System .........................7-85
\Evaporative Emission Control System Including
Onboard Refueling Vapor Recovery (ORVR) .............7-85
Exhaust Emission Control System .............................7-86
Engine ........................................................................\
.......8-2
Engine compartment..................................................1-6, 7-3
Engine Coolant ...............................................................7-26 Changing Engine Coolant ..........................................7-28
Checking the Engine Coolant Level ..........................7-26
Engine Number ...............................................................8-11
Engine Oil .......................................................................7\
-23 Checking the Engine Oil and Filter ...........................7-25
Checking the Engine Oil Level ..................................7-23
Explanation of Scheduled Maintenance Items ...............7-20 Air Cleaner Filter .......................................................7-20
Air Conditioning Refrigerant .....................................7-22
Automatic Transmission Fluid ...................................7-21
Brake Discs, Pads, Calipers and Rotors .....................7-22
Brake Fluid .................................................................7-22
Brake hoses and Lines................................................7-22
Cooling System ..........................................................7-21
Drive Belts..................................................................7-20
Drive Shafts and Boots ..............................................7-22
Ecoshift Dual Clutch Transmission Fluid ..................7-21 Engine Coolant ...........................................................7-21
Engine Oil and Filter ..................................................7-20
Exhaust Pipe and Muffler...........................................7-22
Fuel Filter ...................................................................7-20
Fuel Lines, Fuel Hoses and Connections ...................7-20
Parking Brake .............................................................7-22
Spark Plugs.................................................................7-20
Steering Gear Box, Linkage & Boots/ Lower Arm Ball Joint .............................................7-22
Suspension Mounting Bolts .......................................7-22
Valve Clearance ..........................................................7-21
Vapor Hose and Fuel Filler Cap .................................7-20
Exterior features..............................................................3-52 Fuel Filler Door ..........................................................3-59
Hood ........................................................................\
...3-52
Smart Trunk ................................................................3-56
Trunk ........................................................................\
..3-53
Exterior overview (I) ........................................................1-2
Exterior overview (II) .......................................................1-3
Fuses ........................................................................\
.......7-56 Engine Compartment Panel Fuse Replacement .........7-58
Fuse/Relay Panel Description ....................................7-60
Instrument Panel Fuse Replacement ..........................7-57
Index
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