2018 INFINITI Q70 ignition

8-2Do-it-yourself
When performing any inspection or main-
tenance work on your vehicle, always take
care to prevent serious accidental injury to
yourself or damage to the vehicle. The
following are general precautions which
should be closely observed.
WARNING
.Park the vehicle on a level surface,
apply the parking brake securely and
block the wheels to prevent the
vehicle from moving. Move the shift
lever to P (Park).
. Be sure the ignition switch is in the
OFF or LOCK position when per-
forming any parts replacement or
repairs.
. Never connect or disconnect the
battery or any transistorized compo-
nent while the ignition switch is in the
ON position.
. Never leave the engine or automatic
transmission related component har-
nesses disconnected while the igni-
tion switch is in the ON position.
. If you must work with the engine
running, keep your hands, clothing,
hair and tools away from moving
fans, belts and any other moving parts.
. It is advisable to secure or remove
any loose clothing and remove any
jewelry, such as rings, watches, etc.
before working on your vehicle.
. Always wear eye protection when-
ever you work on your vehicle.
. If you must run the engine in an
enclosed space such as a garage, be
sure there is proper ventilation for
exhaust gases to escape.
. Never get under the vehicle while it is
supported only by a jack. If it is
necessary to work under the vehicle,
support it with safety stands.
. Keep smoking materials, flame and
sparks away from fuel tank and the
battery.
. Your vehicle is equipped with an
automatic engine cooling fan. It may
come on at any time without warn-
ing, even if the ignition key is in the
OFF position and the engine is not
running. To avoid injury, always dis-
connect the negative battery cable
before working near the fan.
. Because the fuel lines are under high
pressure even when the engine is off,
it is recommended you visit an
INFINITI retailer for service of the fuel filter or fuel lines.
CAUTION
.
Do not work under the hood while the
engine is hot. Turn the engine off and
wait until it cools down.
. Avoid direct contact with used en-
gine oil and coolant. Improperly dis-
posed engine oil, coolant, and/or
other vehicle fluids can damage the
environment. Always conform to lo-
cal regulations for disposal of vehicle
fluid.
This “8. Do-it yourself” section gives instruc-
tions regarding only those items which are
relatively easy for an owner to perform.
A genuine INFINITI Service Manual is also
available. (See “Owner’s Manual/Service
Manual order information” (P.10-26).)
You should be aware that incomplete or
improper servicing may result in operating
difficulties or excessive emissions, and could
affect your warranty coverage. If in doubt
about any servicing, it is recommended you
have it done by an INFINITI retailer.
MAINTENANCE PRECAUTIONS

8-18Do-it-yourself
CAUTION
.Do not ground accessories directly to
the battery terminal. Doing so will
bypass the variable voltage control
system and the vehicle battery may
not charge completely.
. Use electrical accessories with the
engine running to avoid discharging
the vehicle battery.
The variable voltage control system mea-
sures the amount of electrical discharge
from the battery and controls voltage gen-
erated by the generator.
SDI2545
VK56VD engine
SDI2119
VQ37VHR engine 1. Power steering fluid pump
2. Alternator
3. Crankshaft pulley
4. Air conditioner compressor
5. Drive belt auto-tensioner
WARNING
Be sure the ignition switch is in the OFF
or LOCK position before servicing drive
belts. The engine could rotate unexpect-
edly.
1. Visually inspect each belt for signs of unusual wear, cuts, fraying or looseness.
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.
VARIABLE VOLTAGE CONTROL SYSTEMDRIVE BELTS

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.
SDI2549
VK56VD engine
Do-it-yourself8-19
SPARK PLUGSAIR CLEANER

SDI2584
SDI2566
ENGINE COMPARTMENT
WARNING
Never use a fuse of a higher or lower
amperage rating than that specified on
the fuse box cover. This could damage
the electrical system or electronic con-
trol units or cause a fire.
If any electrical equipment does not operate,
check for an open fuse.
1. Be sure the ignition switch is pushed to the OFF or LOCK position and the
headlight switch is turned to OFF.
2. Open the engine hood and remove the cover on the battery and the fuse/fusible
link holder.
3. Remove the fuse/fusible link holder cover.
4. Remove the fuse with the fuse puller.
SDI1754
5. If the fuse is open, replace it with a
new fuse. Spare fuses are stored in the
passenger compartment fuse box.
6. If a new fuse also opens, have the electrical system checked and repaired.
It is recommended you visit an INFINITI
retailer for this service.
The holder
also contains the fuses. It is
recommended you visit an INFINITI retailer
for checking and/or replacing.
Do-it-yourself8-23
FUSES

8-24Do-it-yourself
Fusible links
If any electrical equipment does not operate
and fuses are in good condition, check the
fusible links. If any of these fusible links are
melted, replace only with genuine INFINITI
parts.
SDI2034
PASSENGER COMPARTMENT
CAUTION
Never use a fuse of a higher or lower
amperage rating than that specified on
the fuse box cover. This could damage
the electrical system or cause a fire.
If any electrical equipment does not operate,
check for an open fuse.
1. Be sure the ignition switch is pushed to the OFF or LOCK position and the
headlight switch is turned to OFF. 2. Open the fuse box lid.
3. Remove the fuse with the fuse puller
.
4. If the fuse is open, replace it with a new fuse.
5. If a new fuse also opens, have the electrical system checked and repaired.
It is recommended you visit an INFINITI
retailer for this service. Spare fuses are
stored in the fuse box.

problems and/or fuel system damage.
.The fuel should be unleaded and have an
octane rating no lower than that re-
commended for unleaded gasoline.
. If an oxygenate-blend, excepting a
methanol blend, is used, it should con-
tain no more than 15% oxygenate.
. If a methanol blend is used, it should
contain no more than 5% methanol
(methyl alcohol, wood alcohol). It should
also contain a suitable amount of ap-
propriate cosolvents and corrosion in-
hibitors. If not properly formulated with
appropriate cosolvents and corrosion
inhibitors, such methanol blends may
cause fuel system damage and/or vehi-
cle performance problems. At this time,
sufficient data is not available to ensure
that all methanol blends are suitable for
use in INFINITI vehicles.
If any undesirable driveability problems such
as engine stalling or hard hot starting are
experienced after using oxygenate-blend
fuels, immediately change to a non-oxyge-
nate fuel or a fuel with a low blend of MTBE.
Take care not to spill gasoline during
refueling. Gasoline containing oxygenates
can cause paint damage.E-15 fuel
E-15 fuel is a mixture of approximately 15%
fuel ethanol and 85% unleaded gasoline. E-
15 can only be used in vehicles designed to
run on E-15 fuel. U.S. government regula-
tions require fuel ethanol dispensing pumps
to be identified with small, square, orange
and black label with the common abbrevia-
tion or the appropriate percentage for that
region.
E-85 fuel
E-85 fuel is a mixture of approximately 85%
fuel ethanol and 15% unleaded gasoline. E-
85 can only be used in a Flexible Fuel Vehicle
(FFV). Do not use E-85 fuel in your vehicle.
U.S. government regulations require fuel
ethanol dispensing pumps to be identified
by a small, square, orange and black label
with the common abbreviation or the appro-
priate percentage for that region.
Fuel containing MMT
MMT, or methylcyclopentadienyl manga-
nese tricarbonyl, is an octane boosting
additive. INFINITI does not recommend the
use of fuel containing MMT. Such fuel may
adversely affect vehicle performance, in-
cluding the emissions control system. Note
that while some fuel pumps label MMT
content, not all do, so you may have to consult your gasoline retailer for more de-
tails.
Aftermarket fuel additives
INFINITI does not recommend the use of any
aftermarket fuel additives (Example: fuel
injector cleaner, octane booster, intake valve
deposit removers, etc.) which are sold com-
mercially. Many of these additives intended
for gum, varnish or deposit removal may
contain active solvent or similar ingredients
that can be harmful to the fuel system and
engine.
Octane rating tips
Using unleaded gasoline with an octane
rating lower than recommended above can
cause persistent, heavy spark knock. (Spark
knock is a metallic rapping noise.) If severe,
this can lead to engine damage. If you
detect a persistent heavy spark knock even
when using gasoline of the stated octane
rating, or if you hear steady spark knock
while holding a steady speed on level roads,
it is recommended you have an INFINITI
retailer correct the condition. Failure to
correct the condition is misuse of the
vehicle, for which INFINITI is not respon-
sible.
Incorrect ignition timing will result in knock-
ing, after-run or overheating. This in turn
may cause excessive fuel consumption or
Technical and consumer information10-5

10-8Technical and consumer information
that can be harmful to the fuel system and
engine.
Octane rating tips
Using unleaded gasoline with an octane
rating lower than recommended above can
cause persistent, heavy spark knock. (Spark
knock is a metallic rapping noise.) If severe,
this can lead to engine damage. If you
detect a persistent heavy spark knock even
when using gasoline of the stated octane
rating, or if you hear steady spark knock
while holding a steady speed on level roads,
it is recommended you have an INFINITI
retailer correct the condition. Failure to
correct the condition is misuse of the
vehicle, for which INFINITI is not respon-
sible.
Incorrect ignition timing will result in knock-
ing, after-run or overheating. This in turn
may cause excessive fuel consumption or
damage to the engine. If any of the above
symptoms are encountered, have your ve-
hicle checked. It is recommended you visit an
INFINITI retailer for this service or other
competent service facility.
However, now and then you may notice
light spark knock for a short time while
accelerating or driving up hills. This is no
cause for concern, because you get the
greatest fuel benefit when there is light
spark knock for a short time under heavyengine load.

ENGINE
ModelVK56VDVQ37VHR
Type Gasoline, 4-cycleGasoline, 4-cycle
Cylinder arrangement 8-cylinder, V-slanted at 90° 6-cylinder, V-slanted at 60°
Bore × Stroke in (mm) 3.858 × 3.622
(98.0 × 92.0)3.760 × 3.385
(95.5 × 86.0)
Displacement cu in (cm
3) 338.78 (5,552) 225.54 (3,696)
Firing order 1-8-7-3-6-5-4-21-2-3-4-5-6
Idle speed rpm No adjustment is necessary.
Ignition timing
(B.T.D.C.) degree/rpm
Spark plug DILKAR7B11FXE24HR11
Spark plug gap
(Normal) in (mm)
0.043 (1.1) 0.043 (1.1)
Camshaft operation Timing chainTiming chain
This spark ignition system complies with the Canadian standard ICES-002.
STI0397B
VK56VD engine
STI0425
VQ37VHR engine
Technical and consumer information10-11
SPECIFICATIONS