2011 SUBARU IMPREZA WRX STI check engine

Black plate (21,1)
北米Model "A1110BE-C" EDITED: 2010/ 11/ 17
Maintenance schedule ....................................... 11-3
Maintenance precautions ................................... 11-3
Before checking or servicing in the engine
compartment .................................................... 11-4
When checking or servicing in the engine compartment .................................................... 11-4
When checking or servicing in the engine compartment while the engine is running .......... 11-5
Engine hood....................................................... 11-5
Engine compartment overview .......................... 11-7
Non-turbo models.............................................. 11-7
Turbo models except STI .................................... 11-8
STI..................................................................... 11-9
Engine oil .......................................................... 11-10
Checking the oil level ....................................... 11-10
Changing the oil and oil filter ............................ 11-11
Recommended grade and viscosity .................. 11-13
Synthetic oil ..................................................... 11-13
Cooling system ................................................ 11-13
Cooling fan, hose and connections ................... 11-14
Engine coolant ................................................. 11-14
Air cleaner element .......................................... 11-17
Replacing the air cleaner element ..................... 11-17
Spark plugs...................................................... 11-19
Recommended spark plugs .............................. 11-20
Drive belts........................................................ 11-20
Manual transmission oil .................................. 11-21
Checking the oil level....................................... 11-21
Recommended grade and viscosity .................. 11-21
Automatic transmission fluid.......................... 11-22
Checking the fluid level.................................... 11-22
Recommended fluid ......................................... 11-23
Front differential gear oil (AT models) ........... 11-23
Checking the oil level...................................... 11-23
Recommended grade and viscosity .................. 11-24
Rear differential gear oil.................................. 11-24
Recommended grade and viscosity .................. 11-24
Power steering fluid........................................ 11-24
Checking the fluid level .................................... 11-24
Recommended fluid ......................................... 11-25
Brake fluid........................................................ 11-25
Checking the fluid level .................................... 11-25
Recommended brake fluid ............................... 11-26
Clutch fluid (MT models)................................. 11-26
Checking the fluid level.................................... 11-26
Recommended clutch fluid ............................... 11-27
Brake booster.................................................. 11-27
Brake pedal ...................................................... 11-28
Checking the brake pedal free play .................. 11-28
Checking the brake pedal reserve distance....... 11-28
Clutch pedal (MT models) ............................... 11-29
Checking the clutch function ............................ 11-29
Checking the clutch pedal free play .................. 11-29
Hill start assist system (MT models –if
equipped) ...................................................... 11-29
Replacement of brake pad and lining ............ 11-30
Breaking-in of new brake pads and linings ....... 11-30
Parking brake stroke....................................... 11-31
Maintenance and service
11

Black plate (364,1)
北米Model "A1110BE-C" EDITED: 2010/ 12/ 17
11-4
Maintenance and service
guard against getting oil or fluids
in your eyes. If something does
get in your eyes, thoroughly
wash them out with clean water.
. Do not tamper with the wiring of
the SRS airbag system or seat-
belt pretensioner system, or at-
tempt to take its connectors
apart, as that may activate the
system or it can render it inop-
erative. NEVER use a circuit
tester for this wiring.
If your SRS airbag or seatbelt
pretensioner needs service, con-
sult your nearest SUBARU deal-
er.
& Before checking or servicing
in the engine compartment
WARNING
. Always stop the engine and set
the parking brake firmly to pre-
vent the vehicle from moving.
. Always let the engine cool down.
Engine parts become very hot
when the engine is running and
remain hot for some time after
the engine is stopped.
. Do not spill engine oil, engine
coolant, brake fluid or any other
fluid on hot engine components.
This may cause a fire.
. Always remove the key from the
ignition switch. When the ignition
switch is in the “ON ”position,
thecoolingfanmayoperate
suddenly even when the engine
is stopped.
. Before performing any servicing
on a vehicle equipped with a
remote engine start system (a
dealer option) temporarily place
that system in the service mode
to prevent it from unexpectedly
starting the engine.
& When checking or servicing
in the engine compartment
CAUTION
Do not contact the belt cover while
checking the components in the
engine compartment. Doing so may
cause your hand to slip off the belt
cover and result in an unexpected
injury.

Black plate (365,1)
北米Model "A1110BE-C" EDITED: 2010/ 12/ 17
& When checking or servicing
in the engine compartment
while the engine is running
WARNING
A running engine can be dangerous.
Keep your fingers, hands, clothing,
hair and tools away from the cooling
fan, belts and any other moving
engine parts. Removing rings,
watches and ties is advisable.
Engine hoodTo 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 5.9 in (15 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
thehoodforciblytocloseit.Itcould
deform the metal.
Maintenance and service
11-5
–CONTINUED –
11

Black plate (370,1)
北米Model "A1110BE-C" EDITED: 2010/ 12/ 17
11-10
Maintenance and service
Engine oilNOTE. The engine oil consumption rate is
not stabilized, and therefore cannot be
determined until the vehicle has tra-
veled at least several thousand miles
(kilometers). Even after break-in, when
the vehicle is used under severe driv-
ing conditions such as those men-
tionedintheWarrantyandMainte-
nance Booklet, engine oil is consumed
or deteriorated more quickly than un-
der normal driving conditions. If you
drive your vehicle under these severe
conditions, you should check the oil
level at least at every second fuel fill-up
time, and change the oil more fre-
quently. Please refer to the Warranty
and Maintenance Booklet for more de-
tails.
. If the oil consumption rate seems
abnormally high after the break-in
period, for example more than 1 quart
per 1,200 miles or 1 liter per 2,000
kilometers, contact your SUBARU deal-
er.
& Checking the oil levelCheck the engine oil level at each fuel
stop.
1. Park the vehicle on a level surface and
stop the engine.2. Pull out the level gauge that has the
“
”symbol on top, wipe it clean, and
insert it again.
3. Be sure the level gauge is correctly
inserted until it stops.
1) Notch
2) Upper level
3) Lower level4. Pull out the level gauge again and
check the oil level on it. If it is below the
lower level, add oil to bring the level up to
the upper level.
CAUTION
. 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

Black plate (371,1)
北米Model "A1110BE-C" EDITED: 2010/ 12/ 17
pipe, be sure to wipe it off.
. 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.
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.
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.
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 filterChange the oil and oil filter according to
the maintenance schedule in the “War-
ranty and Maintenance Booklet ”.
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.
NOTEChanging the engine oil and oil filter
should be performed by a properly-
trained expert. It is recommended that
you have this service performed by
your SUBARU dealer.
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.Turbo models
Non-turbo models4. 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.
6. Remove the under cover.
Maintenance and service
11-11
– CONTINUED –
11

Black plate (372,1)
北米Model "A1110BE-C" EDITED: 2010/ 12/ 17
11-12
Maintenance and service
Turbo modelsNon-turbo models7. Remove the oil filter with an oil filter
wrench.
8. Before installing a new oil filter, apply a
thin coat of engine oil to the seal. 9. Clean the rubber seal seating area of
the bottom of engine and install the oil
filter by hand turning. Be careful not to
twist or damage the seal.
10. Tighten the oil filter by the amount
indicated in the following table after the
seal makes contact with the bottom of
engine.
Oil filter color Part number
Amount of
rotation
Black 15208AA100 1 rotation
Blue 15208AA12A 7/8
rotation
CAUTION
. Never over tighten the oil filter
because that can result in an oil
leak.
. 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.
11. Reinstall under cover.
12. Pour engine oil through the filler neck.
For the oil capacity (guideline), refer to
“Engine oil ”F 12-5. 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.
13. Start the engine and make sure that no
oil leaks appear around the filter
’s rubber
seal and drain plug.
14. 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.

Black plate (374,1)
北米Model "A1110BE-C" EDITED: 2010/ 12/ 17
11-14
Maintenance and service
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-
nectionsYour 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 following conditions occur,
the cooling fan circuit may be defective.
. For turbo models, the engine coolant
temperature gauge exceeds the normal
operating range. Refer to “Temperature
gauge (turbo models) ”F 3-11.
. For non-turbo models, the coolant
temperature high warning light blinks or
illuminates in RED. Refer to “Coolant
temperature low indicator light (non-turbo
models)/Coolant temperature high warn-
ing light (non-turbo models) ”F 3-17.
Check the fuse and replace it if necessary.
Refer to “Fuses”F 11-45 and “Fuse panel
located in the engine compartment” F12-
14. 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
WARNING
Never attempt to remove the radia-
tor cap until the engine has been
shut off and has cooled down
completely. Since the coolant is
under pressure, you may suffer
serious burns from a spray of boil-
ing hot coolant when the cap is
removed.
1) “FULL ”level mark
2) “LOW ”level markCheck 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
as required.

Black plate (375,1)
北米Model "A1110BE-C" EDITED: 2010/ 12/ 17
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.
WARNING
Never attempt to remove the radia-
tor cap until the engine has been
shut off and has cooled down
completely. Since the coolant is
under pressure, you may suffer
serious burns from a spray of boil-
ing hot coolant when the cap is
removed.
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
WARNING
Never attempt to remove the radia-
tor cap until the engine has been
shut off and has cooled down
completely. Since the coolant is
under pressure, you may suffer
serious burns from a spray of boil-
ing hot coolant when the cap is
removed.
Always add genuine SUBARU coolant
and genuine SUBARU cooling system
conditioner whenever the coolant is re-
placed. Change the engine coolant and add
genuine SUBARU cooling system condi-
tioner using the following procedures
according to the maintenance schedule.
1. Remove the under cover.
2. Place a proper container under the
drain plug and loosen the drain plug.
3. Loosen the radiator cap to drain the
coolant from the radiator. Then drain the
coolant from the reserve tank. Tighten the
drain plug securely.NOTE (Turbo models only)The cap (without tabs) on top of the
radiator does not need to be removed.
To add coolant, remove the cap (with
tabs) on the coolant tank on top of the
engine.
Maintenance and service
11-15
–
CONTINUED –
11