2021 INFINITI Q50 spark plugs replace

8 Do-it-yourself
Maintenance precautions ............................................... 8-2
Engine compartment check locations ......................... 8-3VR30DDTT engine ..................................................... 8-3
Engine cooling system ..................................................... 8-3 Checking engine coolant level ................................ 8-4
Changing engine coolant .......................................... 8-5
Intercooler cooling system ............................................. 8-5 Checking intercooler coolant level ......................... 8-6
Changing intercooler coolant .................................. 8-6
Engine oil ........................................................................\
..... 8-7
Checking engine oil level ........................................... 8-7
Changing engine oil and filter .................................. 8-7
Automatic Transmission Fluid (ATF) .......................... 8-9
Brake fluid ........................................................................\
8-10
Window washer fluid ................................................... 8-10
Battery ........................................................................\
....... 8-11
Checking battery fluid level .................................... 8-12
Jump starting ............................................................. 8-13
Variable voltage control system ................................. 8-13
Drive belts ........................................................................\
. 8-13
Spark plugs ....................................................................... 8-14 Replacing spark plugs .............................................. 8-14 Air cleaner ........................................................................\
8-15
Windshield wiper blades .............................................. 8-15
Cleaning ..................................................................... 8-15
Replacing ................................................................... 8-16
Brakes ........................................................................\
........ 8-16 Self-adjusting brakes ............................................. 8-16
Brake pad wear warning ....................................... 8-16
Fuses ........................................................................\
.......... 8-17 Engine compartment .............................................. 8-17
Passenger compartment ....................................... 8-18
Intelligent Key battery replacement ......................... 8-19
Lights ........................................................................\
......... 8-22 Headlights ................................................................. 8-23
Exterior and interior lights .................................... 8-23
Wheels and tires ............................................................. 8-25 Tire pressure ............................................................. 8-25
Tire labeling .............................................................. 8-29
Types of tires ........................................................... 8-31
Tire chains ................................................................. 8-33
Changing wheels and tires .................................. 8-34
Jacking up the vehicle and replacing tires ....... 8-37

8-14Do-it-yourself
If the belt is in poor condition or loose,
have it replaced or adjusted. It is recom-
mended you visit an INFINITI retailer for
this service.
2. Have the belts checked regularly for condition and tension in accordance with
the maintenance schedule shown in the
“9. Maintenance and schedules” section.
WARNING
Be sure the engine and the ignition
switch are off and that the parking
brake is engaged securely.
CAUTION
Be sure to use the correct socket to
remove the spark plugs. An incorrect
socket can damage the spark plugs.
SDI2020
REPLACING SPARK PLUGS
If replacement is required, it is recommended
you visit an INFINITI retailer for this service.
Iridium-tipped spark plugs
It is not necessary to replace the iridium-
tipped spark plugs as frequently as the
conventional type spark plugs since they will
last much longer. Follow the maintenance
schedule shown in the “9. Maintenance and
schedules” section, but do not reuse them by
cleaning or regapping.
Always replace spark plugs with recom-
mended or equivalent ones.
SPARK PLUGS

The following descriptions are provided to
give you a better understanding of the
scheduled maintenance items that should
be regularly checked or replaced. The main-
tenance schedule indicates at which mile-
age/time intervals each item requires
service.
In addition to scheduled maintenance, your
vehicle requires that some items be checked
during normal day-to-day operation. Refer
to “General maintenance” (P.9-2).
Items marked with “*” are recommended by
INFINITI for reliable vehicle operation. You
are not required to perform maintenance on
these items in order to maintain the warran-
ties which come with your vehicle. Other
maintenance items and intervals are re-
quired.
When applicable, additional information can
be found in the “8. Do-it yourself” section of
this manual.
NOTE:
INFINITI does not advocate the use of non-
OEM approved aftermarket flushing sys-
tems and strongly advises against perform-
ing these services on an INFINITI product.
Many of the aftermarket flushing systems
use non-OEM approved chemicals or sol-
vents, the use of which has not been
validated by INFINITI.
For recommended fuel, lubricants, fluids,grease, and refrigerant, refer to “Capacities
and recommended fluids/lubricants” (P.10-
2) of this manual.
EMISSION CONTROL SYSTEM
MAINTENANCE
Drive belts*:
Check engine drive belts for wear, fraying or
cracking and for proper tension. Replace any
damaged drive belts.
Engine air filter:
Replace at specified intervals. When driving
for prolonged periods in dusty conditions,
check/replace the filter more frequently.
Engine coolant*:
Replace coolant at the specified interval.
When adding or replacing coolant, be sure to
use only Genuine NISSAN Long Life Anti-
freeze/Coolant (blue) or equivalent with the
proper mixture. (Refer to “Engine cooling
system” (P.8-3) to determine the proper
mixture for your area.)
NOTE:
Mixing any other type of coolant or the use
of non-distilled water may reduce the
recommended service interval of the cool-
ant.
Intercooler coolant:
Intercooler coolant is maintenance-free.
Engine oil and oil filter:
Replace engine oil and oil filter at the
specified intervals. For recommended oil
grade and viscosity refer to “Capacities and
recommended fluids/lubricants” (P.10-2).
Engine valve clearance*:
Inspect only if valve noise increases. Adjust
valve clearance if necessary.
Evaporative emissions control vapor lines*:
Check vapor lines for leaks or looseness.
Tighten connections or replace parts as
necessary.
Fuel lines*:
Check the fuel hoses, piping and connections
for leaks, looseness, or deterioration. Tight-
en connections or replace parts as necessary.
Spark plugs:
Replace at specified intervals. Install new
plugs of the type as originally equipped.
CHASSIS AND BODY MAINTE-
NANCE
Brake lines and cables:
Visually inspect for proper installation.
Check for chafing, cracks, deterioration,
and signs of leaking. Replace any deterio-
rated or damaged parts immediately.
Brake pads, rotors, drums and linings:
Maintenance and schedules9-5
EXPLANATION OF SCHEDULED
MAINTENANCE ITEMS

Severe maintenance:.Inspect brake pads and rotors.Inspect exhaust system.Inspect steering gear and linkage.Inspect axle and suspension parts.Inspect propeller shaft (AWD models).Inspect drive shaft boots (AWD models).Replace brake fluid.Replace transfer fluid.Replace differential gear oil
(1) Replace the drive belts if found damaged.
(2) Inspect the clearance between the brake pedal
and the switches.
(3) If the oil replacement indicator is displayed,
change the engine oil and filter as soon as
possible. After replacing the engine oil, reset the
display.
(4) If your vehicle is equipped with different sized
tires in the front and rear, tires cannot be rotated.
105,000 Miles/126 Months/
168,000 Km
Standard maintenance:.Replace In-cabin microfilter.Replace Intelligent Key battery.Perform tire rotation (1).Replace spark plugs (2) (3).Replace engine coolant* (4) Severe maintenance:
.Inspect brake pads and rotors.Inspect exhaust system.Inspect steering gear and linkage.Inspect axle and suspension parts.Inspect propeller shaft (AWD models).Inspect drive shaft boots (AWD models)
(1) If your vehicle is equipped with different sized
tires in the front and rear, tires cannot be rotated.
(2) Performed based on the number of miles only.
(3) Replace spark plug when the plug gap exceeds
0.043 in (1.1 mm) even if within specified periodic
replacement mileage.
(4) First replacement interval is 105,000 miles
(168,000 km) or 84 months. After first replace-
ment, replace every 75,000 miles (120,000 km)
or 60 months.
*: Maintenance items and intervals with "*" are
recommended by INFINITI for reliable vehicle
operation. The owner need not perform such
maintenance in order to maintain the emission
warranty or manufacturer recall liability. Other
maintenance items and intervals are required.
Maintenance and schedules9-17