check engine SUBARU WRX 2016 Service Manual

& When checking or servicing
in the engine compartment
CAUTION. Do not contact the drive belt
cover while checking the compo-
nents in the engine compart-
ment. Doing so may cause your
hand to slip off the cover and
result in an unexpected injury.
. Do not touch the oil filter until the
engine has cooled down comple-
tely. Doing so may result in a
burn or other injury. Note that the
oil filter becomes very hot when
the engine is running and re-
mains hot for some time after
the engine has stopped.
. Do not apply force on the fender
insulator by placing your hands on it, etc. Deformation of the
insulator and its mount may
occur.
& When checking or servicing
in the engine compartment
while the engine is running WARNINGA running engine can be dangerous.
Keep your fingers, hands, clothing,
hair and tools away from the cooling
fan, drive belt and any other moving
engine parts. Removing rings,
watches and ties is advisable.Maintenance and service/Maintenance precautions
11-5

Engine hood To open the hood:
1. If the wiper blades are lifted off the
windshield, return them to their original
position.
2. Pull the hood release knob under the
instrument panel. 3. Release the secondary hood release
by moving the lever between the front
grille and the hood toward the left.
4. Lift up the hood.
To close the hood:
1. Lower the hood to a height of approxi-
mately 11.8 in (30 cm) above its closed
position and then let it drop.
2. After closing the hood, be sure the
hood is securely locked.
If this does not close the hood, release it
from a slightly higher position. Do not push
the hood forcibly to close it. It could
deform the metal. WARNINGAlways check that the hood is
properly locked before you start
driving. If it is not, it might fly open
while the vehicle is moving and
block your view, which may cause
an accident and serious bodily in-
jury.
CAUTION. When you open the engine hood,
do not stand the wiper blades up.
Furthermore, while the hood is
open, do not operate the wind-
shield wipers. Doing so could
result in damage to the engine
hood and wiper blades.
. Be extremely careful not to catch
fingers or other objects when
closing the engine hood.
. Do not push the hood forcibly to
close it. It could deform the
metal.
. Be extremely careful opening the
engine hood when the wind is
strong. The engine hood could
close suddenly, possibly causing
injuries from slamming.
. Do not install accessories other Maintenance and service/Engine hood
– CONTINUED –11-9

Engine oil CAUTION. If the level gauge is not pulled out
easily, twist the level gauge right
and left, then pull it out. Other-
wise, you may be injured acci-
dentally straining yourself.
. 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.
& Engine oil consumption Some engine oil will be consumed while
driving. Under the following conditions, oil
consumption can be increased and thus
require refilling between maintenance
intervals:
. When the engine is new and within the
break-in period
. When the engine oil is of lower quality
. When the incorrect oil viscosity is used . When engine braking is employed
. When the engine is operated at high
engine speeds
. When the engine is operated under
heavy loads
. When the engine idles for long periods
of time
. When the vehicle is operated in stop
and go and/or heavy traffic situations
. When the vehicle is used under severe
thermal conditions
. When the vehicle accelerates and
decelerates frequently
Under these or similar conditions, you
should check your oil at least every 2nd
fuel fill-up and change your engine oil
more frequently. If your oil consumption
rate is greater than 1 quart every 1,200
miles or 1 liter every 2,000 kilometers,
contact your SUBARU dealer who may
perform a test under controlled conditions.
& Checking the oil level 1. Park the vehicle on a level surface and
stop the engine. If you check the oil level
just after stopping the engine, wait a few
minutes for the oil to drain back into the oil
pan before checking the level. STI
1) Oil level gauge
2) Oil filler capMaintenance and service/Engine oil
– CONTINUED –11-13

Maintenance and service/Engine oil
Except STI
1) Oil level gauge
2) Oil filler cap
3) Oil filter
CAUTION
If the level gauge is not pulled out
easily, twist the level gauge right
and left, then pull it out. Otherwise,
you may be injured accidentally
straining yourself.
2. Pull out the level gauge, wipe it clean,
and insert it again.
3. Be sure the level gauge is correctly
inserted until it stops. STI
1) Notch
2) Full level
3) Low level
4) Approximately 1.1 US qt (1.0 liter, 0.9
Imp qt) from low level to full level Except STI
1) Full level
2) Low level
3) Approximately 1.1 US qt (1.0 liter, 0.9
Imp qt) from low level to full level
4. Pull out the oil level gauge again.
5. STI:
Check the oil level on the gauge. If the oil
level is below the low level mark, add oil
so that the full level is reached.
Except STI:
Check the oil levels on both sides of the
level gauge. The engine oil level must be
judged by the lowest of the two levels. If
the oil level is below the low level mark,
add oil so that the full level is reached.11-14

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

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

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

Maintenance and service/Clutch pedal (MT models)
& Checking the brake pedal
reserve distance
1) More than 2.56 in (65 mm)
Depress the pedal with a force of approxi-
mately 66 lbf (294 N, 30 kgf) and measure
the distance between the upper surface of
the pedal pad and the floor.
When the measurement is smaller than
the specification, or when the pedal does
not operate smoothly, contact with your
SUBARU dealer. Clutch pedal (MT models) Check the clutch pedal free play and
reserve distance according to the main-
tenance schedule in the “ Warranty and
Maintenance Booklet ” .
& Checking the clutch function Check the clutch engagement and disen-
gagement.
1. With the engine idling, check that there
are no abnormal noises when the clutch
pedal is depressed, and that shifting into
1st or reverse feels smooth.
2. Start the vehicle by releasing the pedal
slowly to check that the engine and
transmission smoothly couple without
any sign of slippage. & Checking the clutch pedal
free play
1) 0.16 – 0.43 in (4.0 – 11.0 mm)
Lightly depress the clutch pedal down with
your finger until you feel resistance, and
check the free play.
If the free play is not within proper
specification, contact your SUBARU deal-
er.11-28