spark plugs replace Hyundai Sonata Plug-in Hybrid 2018 Owner's Manual

5-108
Driving your vehicle
Check battery and cables
The winter temperature increases
the battery consumption. Inspect
the battery and cables, as speci-
fied in the chapter 7. The battery
charging level can be checked by an
authorized HYUNDAI dealer or in a
service station.
Change to "winter weight" oil if
necessary
In some regions during winter, it is
recommended to use the "winter
weight" oil with lower viscosity. For
further information, refer to the chap-
ter 8. When you are not sure about a
type of winter weight oil, consult an
authorized HYUNDAI dealer. Check spark plugs and ignition
system
Inspect the spark plugs, as speci-
fied in the chapter 7.
If necessary,
replace them. Also check all ignition
wirings and components for any
cracks, wear-out, and damage.
To prevent locks from freezing
To prevent the locks from being
frozen, spray approved de-icing fluid
or glycerin into key holes. When a
lock opening is already covered with
ice, spray approved de-icing fluid
over the ice to remove it. When an
internal part of a lock freezes, try to
thaw it with a heated key. Carefully
use the heated key to avoid an injury. Use approved window washer
anti-freeze solution in system
To prevent the window washer from
being frozen, add authorized window
washer anti-freeze solution, as spec-
ified on the window washer contain-
er. Window washer anti-freeze solu-
tion is available from an authorized
HYUNDAI dealer, and so are the
most vehicle accessory outlets. Do
not use engine coolant or other types
of anti-freeze solution to prevent any
damage to the vehicle paint.

7
Maintenance
7-9
Normal Maintenance Schedule
The following maintenance services must be performed to ensure good emission control and performance.
Keep receipts for all vehicle emission services to protect your warranty. Where both mileage and time are shown, the
frequency of service is determined by whichever occurs first.
Number of months or driving distance, whichever comes first
Months1224364860728496108120132144156168180
Miles7.51522.53037.54552.56067.575839098105113
Km1224364860728496108120132144156168180
HSG belts *1Inspect every 7,500 miles or 12 months,
and replace every 67,500 miles or 48 months
Engine oil and engine oil filterRRRRRRRRRRRRRRR
Fuel additives *2Add fuel additives every 7,500 miles or 12months
Air cleaner filterIIIRIIIRIIIRIII
Spark plugsReplace every 97,500 miles
Rotate tiresRotate tires every 7,500 miles
Climate control air filterReplace every 15,000 miles or 12 months
Vacuum hoseIIIIIIIIIIIIIII
Engine coolant / Inverter coolantAt first, replace at 120,000 miles or 10 years :
after that, replace every 30,000 miles or 24 months
MAINTENANCE INTERVALS
MAINTENANCE
ITEM
I : Inspect and if necessary, adjust, correct, clean or replace.
R : Replace or change.
*
1: The drive belt should be replaced when cracks occur or tension is reduced excessively.
*2: If TOP TIER Detergent Gasoline is not available, one bottle of additive is recommended. Additives are available from your authorized HYUNDAI dealer along with information on how to use them. Do not mix other additives.

Maintenance
7-12
Maintenance Under Severe Usage Conditions
The following items must be serviced more frequently on cars normally used under severe driving conditions.
Refer to the chart below for the appropriate maintenance intervals.
R : Replace I : Inspect and, after inspection, clean, adjust, repair or replace if neces\
sary
Maintenance itemMaintenance operationMaintenance intervalsDriving condition
HSG (Hybrid Starter&Generator) belt
REvery 30,000 miles (48,000 km) or 24 months
C, D, E, L
IEvery 3,750 miles (6,000 km) or 6 months
Engine oil and filterREvery 3,750 miles (6,000 km) or 6 monthsA, B, C, D, E,
F, G, H, I, K
Air cleaner filterRMore frequentlyC, E
Spark plugsRMore frequentlyB, H
Climate control air filter
(for evaporator and blower unit)RMore frequentlyC, E
Front brake disc/pads, calipersIMore frequentlyC, D, G, H

7-14
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.
HSG (Hybrid starter & genera-
tor) belt
The HSG belt should be changed at
the intervals specified in the mainte-
nance schedule.
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 con-
nections
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.