2016 SUBARU WRX engine

CAUTION. For models except STI, be careful
not to touch the engine oil filter
when removing the oil filler cap.
Doing so may result in a burn, a
pinched finger, or may cause
some other injury.
. Use only engine oil with the
recommended grade and vis-
cosity.
. Be careful not to spill engine oil
when adding it. If oil touches the
exhaust pipe, it may cause a bad
smell, smoke, and/or a fire. If
engine oil gets on the exhaust
pipe, be sure to wipe it off.
To add engine oil, remove the engine oil
filler cap and slowly pour engine oil
through the filler neck. After pouring oil
into the engine, you must use the level
gauge to confirm that the oil level is
correct.
For models STI, just after driving or while
the engine is warm, the engine oil level
reading may be in a range between the
upper level and the notch mark. This is
caused by thermal expansion of the
engine oil. NOTE To prevent overfilling the engine oil, do
not add any additional oil above the
upper level when the engine is cold.
& Changing the oil and oil filter Change the oil and oil filter according to
the maintenance schedule in the “ War-
ranty and Maintenance Booklet ” .
NOTE . Changing the engine oil and oil filter
should be performed by a well-trained
expert. Contact your SUBARU dealer
for changing the engine oil and oil filter.
Fully trained mechanics are on standby
at a SUBARU dealer to utilize the
special tools, spare parts and recom-
mended oil for this work, and also,
used oils are properly disposed of.
. If performing oil replacement your-
self, observe the local regulations and
dispose of waste oil properly.
The engine oil and oil filter must be
changed more frequently than listed in
the maintenance schedule when driving
on dusty roads, when short trips are
frequently made, or when driving in
extremely cold weather. ! Changing the oil filter
It may be difficult to change the oil filter.
Have the oil filter changed by your
SUBARU dealer if necessary.
! Changing the oil
1. Warm up the engine by letting the
engine idle for approximately 10 minutes
to ease draining the engine oil.
2. Park the vehicle on a level surface and
stop the engine.
3. Remove the oil filler cap.
STIMaintenance and service/Engine oil
– CONTINUED –11-15

Maintenance and service/Engine oil
Except STI
4. Drain out the engine oil by removing
the drain plug while the engine is still
warm. The used oil should be drained into
an appropriate container and disposed of
properly.
WARNING
Be careful not to burn yourself with
hot engine oil.
5. Wipe the seating surface of the drain
plug with a clean cloth and tighten it
securely with a new sealing washer after
the oil has completely drained out.
CAUTION
Thoroughly wipe off any engine oil that has spilled over the exhaust
pipe and/or under-cover. If spilled oil
is not promptly wiped up, the oil
could cause a fire.
6. Pour engine oil through the filler neck.
For the oil capacity (guideline), refer to
“ Engine oil ” F 12-4.
The oil quantity indicated above is only
guideline.
The necessary quantity of oil depends on
the quantity of oil that has been drained.
The quantity of drained oil differs slightly
depending on the temperature of the oil
and the time the oil is left flowing out. After
refilling the engine with oil, therefore, you
must use the level gauge to confirm that
the level is correct.
7. Start the engine and make sure that no
oil leaks appear around the drain plug.
8. Run the engine until it reaches the
normal operating temperature. Then stop
the engine and wait a few minutes to allow
the oil drain back. Check the oil level
again and if necessary, add more engine
oil.
CAUTION
Be careful not to spill engine oil
when adding it. If oil touches the exhaust pipe, it may cause a bad
smell, smoke, and/or a fire.
& Recommended grade and
viscosity CAUTIONUse only engine oil with the recom-
mended grade and viscosity.
Refer to “ Engine oil ” F 12-4.
NOTE Engine oil viscosity (thickness) affects
fuel economy. Oils of lower viscosity
provide better fuel economy. However,
in hot weather, oil of higher viscosity is
required to properly lubricate the en-
gine.
& Synthetic oil You must follow the oil and filter changing
intervals shown in the Warranty and
Maintenance booklet.
NOTE Synthetic oil of the grade and viscosity
noted in chapter 12 is the recom-
mended engine oil for optimum engine
performance. Conventional oil may be11-16

used if synthetic oil is unavailable.
Cooling system WARNING. Never attempt to remove the
radiator cap until the engine has
been shut off and has cooled
down completely. Since the cool-
ant is under pressure, you may
suffer serious burns from a spray
of boiling hot coolant when the
cap is removed.
. Be careful of the rotating cooling
fan when the engine hood is
open. When the engine tempera-
ture is high, the cooling fan in the
engine compartment may oper-
ate when the ignition switch is
turned to the “ ON ” position, even
if the engine is stopped. Touch-
ing the cooling fan while it is
rotating may result in injury.
CAUTION
. Vehicles are filled at the factory
with SUBARU Super Coolant that
does not require the first change
for 11 years/137,500 miles (11
years/220,000 km). This coolant
should not be mixed with any other brand or type of coolant
during this period. Mixing with a
different coolant will reduce the
life of the coolant. Should it be
necessary to top up the coolant
for any reason, use only
SUBARU Super Coolant.
If the SUBARU Super Coolant is
diluted with another brand or
type, the maintenance interval is
shortened to that of the mixing
coolant.
. Do not splash the engine coolant
over painted parts. The alcohol
contained in the engine coolant
may damage the paint surface.
& Cooling fan, hose and con-
nections Your vehicle employs an electric cooling
fan which is thermostatically controlled to
operate when the engine coolant reaches
a specific temperature.
If the radiator cooling fan does not operate
even when the engine coolant tempera-
ture gauge exceeds the normal operating
range, the cooling fan circuit may be
defective. Refer to “ Temperature gauge ”
F 3-11. Maintenance and service/Cooling system
– CONTINUED –11-17

Maintenance and service/Cooling system
Check the fuse and replace it if necessary.
Refer to “ Fuses ” F 11-42 and “ Fuses and
circuits ” F 12-10.
If the fuse is not blown, have the cooling
system checked by your SUBARU dealer.
If frequent addition of coolant is neces-
sary, there may be a leak in the engine
cooling system. It is recommended that
the cooling system and connections be
checked for leaks, damage, or looseness.
& Engine coolant! Checking the coolant level
1) “ FULL ” level mark
2) “ LOW ” level mark
Check the coolant level at each fuel stop.
1. Check the coolant level on the outside of the reservoir while the engine is cool.
2. If the level is close to or lower than the
“ LOW ” level mark, add coolant up to the
“ FULL ” level mark. If the reserve tank is
empty, remove the radiator cap and refill
coolant up to just below the filler neck as
shown in the following illustration.
STI
1) Fill up to this level Except STI
1) Fill up to this level
3. After refilling the reserve tank and the
radiator, reinstall the cap and check that
the rubber gaskets inside the radiator cap
are in the proper position.11-18

CAUTION. Be careful not to spill engine
coolant when adding it. If coolant
touches the exhaust pipe, it may
cause a bad smell, smoke, and/or
a fire. If engine coolant gets on
the exhaust pipe, be sure to wipe
it off.
. Do not splash the engine coolant
over painted parts. The alcohol
contained in the engine coolant
may damage the paint surface.
! Changing the coolant
It may be difficult to change the coolant.
Have the coolant changed by your
SUBARU dealer if necessary.
The coolant should be changed according
to the maintenance schedule in the
“ Warranty and Maintenance Booklet ” .Air cleaner element WARNINGDo not operate the engine with the
air cleaner element removed. The air
cleaner element not only filters
intake air but also stops flames if
the engine backfires. If the air
cleaner element is not installed
when the engine backfires, you
could be burned.
CAUTIONWhen replacing the air cleaner ele-
ment, use a genuine SUBARU air
cleaner element. If it is not used,
there is the possibility of causing a
negative effect to the engine.
The air cleaner element functions as a
filter screen. When the element is perfo-
rated or removed, engine wear will be
excessive and engine life shortened.
It is not necessary to clean or wash the air
cleaner element. & Replacing the air cleaner
element Replace the air cleaner element according
to the maintenance schedule in the
“ Warranty and Maintenance Booklet ” . Un-
der extremely dusty conditions, replace it
more frequently. It is recommended that
you always use genuine SUBARU parts.
! STI
1. Use a screwdriver to undo the clips on
the air intake duct, then remove the air
intake duct. Maintenance and service/Air cleaner element
– CONTINUED –11-19

Maintenance and service/Drive belts
Drive belts NOTE For models except STI, it is unneces-
sary to check the deflection of the drive
belt periodically because this engine is
equipped with an automatic belt ten-
sion adjuster. However, replacement of
the belt should be done according to
the maintenance schedule in the “ War-
ranty and Maintenance Booklet ” . Con-
sult your SUBARU dealer for replace-
ment.
If the drive belt is loose, cracked or
worn, contact your SUBARU dealer. STI
1) Power steering oil pump pulley
2) Front side belt
3) Alternator pulley
4) Air conditioner compressor pulley
5) Rear side belt
6) Crank pulley
A) 22 lbf (98 N, 10 kgf)
CAUTION
The front side belt, which runs in
conjunction with the following com-
ponents, must be used within the
specified deflection.
. Power steering oil pump pulley
. Alternator pulley
. Crank pulley
Check the deflection of the front side belt and if there is any loosen-
ess, cracks, wear or unusual noise
on the front side belt, contact your
SUBARU dealer.
Continuing to use the vehicle with
the belt outside of the specification
may cause the engine to malfunc-
tion and the above components to
malfunction.
To check the deflection of the front side
belt, place a straightedge (ruler) across
two adjacent pulleys (alternator pulley and
crank pulley) and apply a force of 22 lbf
(98 N, 10 kgf) midway between the pulleys
by using a spring scale. The belt deflec-
tion should be the amount specified. If the
front side belt is loose, cracked or worn,
contact your SUBARU dealer. in (mm)
Deflection
New belt
Used belt
A 0.28 – 0.35
(7.0 – 9.0) 0.35 – 0.43
(9.0 – 11.0)
The rear side belt is a stretch-type belt,
therefore the deflection does not need to
be checked. If there are cracks or wear
confirmed on the belts and a squeaking
noise is heard from them, contact your
SUBARU dealer.11-22

Maintenance and service/Power steering fluid (STI)
Power steering fluid (STI) & Checking the fluid level
The power steering fluid expands greatly
as its temperature rises; the fluid level
differs according to fluid temperature.
Therefore, the reservoir tank has two
different checking ranges for hot and cold
fluids.
Check the power steering fluid level
monthly.
1. Park the vehicle on a level surface,
and stop the engine.
2. Check the fluid level of the reservoir
tank.
When the fluid is hot after the vehicle has
been run: Check that the oil level is
between “ HOT MIN ” and “ HOT MAX ” on the surface of the reservoir tank.
When the fluid is cool before the vehicle is
run: Check that the oil level is between
“ COLD MIN ” and “ COLD MAX ” on the
surface of the reservoir tank.
3. If the fluid level is lower than the
applicable “ MIN ” line, add the recom-
mended fluid as necessary to bring the
level between the “ MIN ” and “ MAX ” line.
If the fluid level is extremely low, it may
indicate possible leakage. Consult your
SUBARU dealer for an inspection.
WARNINGBe careful not to burn yourself
because the fluid may be hot.
CAUTION
. When power steering fluid is
being added, use only clean fluid,
and be careful not to allow any
dirt into the tank. And never use
different brands together.
. Be careful not to spill power
steering fluid when adding it. If
power steering fluid touches the
exhaust pipe, it may cause a bad
smell, smoke, and/or a fire. If
power steering fluid gets on the exhaust pipe, be sure to wipe it
off.
& Recommended fluid Refer to “ Fluids ” F 12-7.
11-24

Brake booster If the brake booster does not operate as
described in the following, have it checked
by your SUBARU dealer.
1. With the engine off, depress the brake
pedal several times, applying the same
pedal force each time. The distance the
pedal travels should not vary.
2. With the brake pedal depressed, start
the engine. The pedal should move
slightly down to the floor.
3. With the brake pedal depressed, stop
the engine and keep the pedal depressed
for 30 seconds. The pedal height should
not change.
4. Start the engine again and run for
approximately one minute then turn it off.
Depress the brake pedal several times to
check the brake booster. The brake
booster operates properly if the pedal
stroke decreases with each depression.
NOTE When you depress the brake pedal
strongly or suddenly, you might feel
that lighter depression of the brake
pedal generates a greater braking
force. However, even though these
occur, they do not indicate any mal-
functions, and the brake assist system is operating properly.
Brake assist is not a system that brings
more braking ability to the vehicle
beyond its breaking capability.
Brake pedal Check the brake pedal free play and
reserve distance according to the main-
tenance schedule in the “ Warranty and
Maintenance Booklet ” .
& Checking the brake pedal
free play
1) 0.02 – 0.11 in (0.5 – 2.7 mm)
Stop the engine and firmly depress the
brake pedal several times. Lightly pull the
brake pedal up with one finger to check
the free play with a force of less than 2 lbf
(10 N, 1 kgf).
If the free play is not within proper
specification, contact your SUBARU deal-
er. Maintenance and service/Brake booster
– CONTINUED –11-27