2003 SUBARU IMPREZA WRX engine

In case of emergency
9-17
– CONTINUED –
(1) Connect one jumper cable to the positive (+)
terminal on the discharged battery.
(2) Connect the other end of the jumper cable to
the positive (+) terminal of the booster battery.
(3) Connect one end of the other cable to thenegative (–) terminal of the booster battery.
(4) Connect the other end of the cable to the en-gine lifting bracket.
Make sure that the cables are not near any mov-
ing parts and that the cable clamps are not in
contact with any other metal.
5. Start the engine of the vehicle with the booster
battery and run it at moderate speed. Then start the
engine of the vehicle that has the discharged bat-
tery.
6. When finished, carefully disconnect the cables in
exactly the reverse order. Engine overheating
WARNING
Never attempt to remove the radiator cap until the engine has been shut off and has fullycooled down. When the engine is hot, thecoolant is under pressure. Removing the cap
while the engine is still hot could release aspray of boiling hot coolant, which could burn
you very seriously.
If the engine overheats, safely pull off the road and stop the vehicle in a safe place. If steam is coming from the engine compartment
Turn the engine off and get everyone away from the
vehicle until it cools down. If no steam is coming from the engine compartment
1. Keep the engine running at idling speed.
2. Open the hood to ventilate the engine compart-ment.

In case of emergency
9-18
Confirm that the cooling fan is turning. If the fan is
not turning, immediately turn the engine off and con-
tact your authorized dealer for repair.
3. After the engine coolant temperature has
dropped, turn off the engine.
If the temperature gauge stays at the overheated
zone, turn the engine off.
4. After the engine has fully cooled down, check the
coolant level in the reserve tank.If the coolant level is below the “LOW” mark, add
coolant up to the “FULL” mark.
5. If there is no coolant in the reserve tank, add
coolant to the reserve tank. Then remove the radia- tor cap and fill the radiator with coolant.
If you remove the radiator cap from a hot radiator,
first wrap a thick cloth around the radiator cap, then
turn the cap counterclockwise slowly without press-
ing down until it stops. Release the pressure from
the radiator. After the pressure has been fully re-
leased, remove the cap by pressing down and turn-ing it. Towing
If towing is necessary, it is best done by your
SUBARU dealer or a commercial towing service.
Observe the following procedures for safety.
WARNING
Never tow AWD vehicles (both AT and MT) with the front wheels raised off the groundwhile the rear wheels are on the ground, orwith the rear wheels raised off the groundwhile the front wheels are on the ground. This

In case of emergency
9-23
– CONTINUED –
WARNING
Never turn the ignition switch to the “LOCK”
position while the vehicle is being towed be-
cause the steering wheel and the direction ofthe wheels will be locked. Remember that the brake booster and pow-
er steering do not function when the engine is not running. Because the engine is turned off,
it will take greater effort to operate the brakepedal and steering wheel.
CAUTION
If transmission failure occurs, transport
your vehicle on a flat-bed truck. Do not run the engine while being towed in
this method. Transmission damage could re- sult if the vehicle is towed with the engine running. For vehicles with automatic transmission,
the traveling speed must be limited to lessthan 20 mph (30 km/h) and the traveling dis-tance to less than 31 miles (50 km). For greater speeds and distances, transport your
vehicle on a flat-bed truck. Maintenance toolsYour vehicle is equipped with the following mainte-
nance tools:
Wheel cover remover (vehicles with wheel covers)
Screwdriver
Towing hook (eye bolt)
Wheel nut wrench

Appearance care
10-2
Exterior care Washing
The best way to preserve your vehicle ’s beauty is
frequent washing. Wash the vehicle at least once a
month to avoid contamination by road grime.
Wash dirt off with a wet sponge and plenty of luke-
warm or cold water. Do not wash the vehicle with hot
water and in direct sunlight.
Salt, chemicals, insects, tar, soot and bird droppings
should be washed off by using a light detergent, as
required. If you use a light detergent, make certain
that it is a neutral detergent. Do not use strong soap or chemical detergents. All cleaning agents should
be promptly flushed from the surface and not al-
lowed to dry there. Rinse the vehicle thoroughly with
plenty of lukewarm water. Wipe the remaining water
off with a chamois or soft cloth. NOTE When having your vehicle washed in an auto- matic car wash, make sure beforehand that thecar wash is of suitable type. If the vehicle is
equipped with a rear/roof spoiler or rear wiper, itmay be damaged by car wash brushes or otherequipment.
CAUTION
When washing the vehicle, the brakes may
get wet. As a result, the brake stopping dis-
tance will be longer. To dry the brakes, drivethe vehicle at a safe speed while lightly press- ing the brake pedal to heat up the brakes. Do not wash the engine compartment and
area adjacent to it. If water enters the engineair intake, electrical parts or the power steer-
ing fluid reservoir, it will cause engine trouble
or faulty power steering respectively.
Washing the underbody
Chemicals, salts and gravel used for deicing road
surfaces are extremely corrosive, accelerating the
corrosion of underbody components, such as theexhaust system, fuel and brake lines, brake cables,floor pan and fenders, and suspension.
Thoroughly flush the underbody and inside of the
fenders with lukewarm or cold water at frequent in-
tervals to reduce the harmful effects of such agents.
Using a warm water washer
Keep a good distance of 12 in (30 cm) or more
between the washer nozzle and the vehicle.

11
11-1
– CONTINUED –
Maintenance schedule 11-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance precautions 11-3 . . . . . . . . . . . . . . . . . . . . . . . .
Engine hood 11-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine compartment overview 11-8 . . . . . . . . . . . . . . . . .
2.5 liter model 11-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.0 liter (Turbo) model 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 . . . . . . . . . . .
Recommended grade and viscosity under
severe driving conditions 11-15 . . . . . . . . . . . . . . . . . . . . . .
Synthetic oil 11-15
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling system 11-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling fan, hose and connections 11-16 . . . . . . . . . . . .
Engine coolant 11-16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air cleaner element 11-20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing the air cleaner element 11-20 . . . . . . . . . . . . . .
Spark plugs 11-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended spark plugs 11-24 . . . . . . . . . . . . . . . . . . . . .
Drive belts 11-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual transmission oil 11-25 . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the oil level 11-25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-26 . . . . . . . . . . .
Automatic transmission fluid 11-27 . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-27 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended fluid 11-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front differential gear oil (AT vehicles) 11-29
. . . . .
Checking the oil level 11-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-30 . . . . . . . . . . .
Rear differential gear oil 11-31 . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the gear oil level 11-31 . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-32 . . . . . . . . . . .
Power steering fluid 11-32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-32 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended fluid 11-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake fluid 11-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-34 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended brake fluid 11-34 . . . . . . . . . . . . . . . . . . . . . . .
Clutch fluid (MT vehicles) 11-35 . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-35 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended clutch fluid 11-36 . . . . . . . . . . . . . . . . . . . . . .
Brake booster 11-36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake pedal 11-37 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the brake pedal free play 11-37 . . . . . . . . . . . .
Checking the brake pedal reserve distance 11-37 . .
Clutch pedal (MT vehicles) 11-38 . . . . . . . . . . . . . . . . . . . . . .
Checking the clutch function 11-38 . . . . . . . . . . . . . . . . . . . .
Checking the clutch pedal free play 11-38 . . . . . . . . . . .
Replacement of brake pad and lining 11-39 . . . . . . . .
Breaking-in of new brake pads and linings 11-39 . . .
Parking brake stroke 11-40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tires and wheels 11-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Types of tires 11-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance and service

Maintenance and service
11-4
Always be very careful to avoid injury when
working on the vehicle. Remember that some of the materials in the vehicle may be hazard-
ous if improperly used or handled, for exam-ple, battery acid. Your vehicle should only be serviced by per-
sons fully competent to do so. Serious per-sonal injury may result to persons not experi-enced in servicing vehicles. Always use the proper tools and make cer-
tain that they are well maintained. Never get under the vehicle supported only
by a jack. Always use a safety stands to sup-port the vehicle. Never keep the engine running in a poorly
ventilated area, such as a garage or other
closed areas. Do not smoke or allow open flames around
the fuel or battery. This will cause a fire. Because the fuel system is under pressure,
replacement of the fuel filter should be per-
formed only by your SUBARU dealer. Wear adequate eye protection to 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 seatbelt pretensioner sys-tem, or attempt to take its connectors apart,as that may activate the system or it can ren-der it inoperative. The wiring and connectorsof these systems are yellow for easy identifi-cation. NEVER use a circuit tester for these wiring. If your SRS airbag or seatbelt pretensionerneeds service, consult your nearest SUBARU
dealer.
Before checking or servicing in the
engine compartment
Always stop the engine and set the parking
brake firmly to prevent the vehicle from mov- ing. Always let the engine cool down. Engine
parts become very hot when the engine is run-
ning and remain hot for some time after theengine is stopped. Do not spill engine oil, engine coolant, brake
fluid or any other fluid on hot engine compo-nents. This may cause a fire. Always remove the key from the ignition
switch. When the ignition switch is in the
“ON” position, the cooling fan may operate

Maintenance and service
11-5
– CONTINUED –
suddenly even when the engine is stopped. When you do checking or servicing in the engine compartment whilethe engine is running
A running engine can be dangerous. Keep your fingers, hands, clothing, hair and toolsaway from the cooling fan, belts and any other
moving engine parts. Removing rings,watches and ties is advisable. Engine hood
To open the hood:
1. Pull the hood release knob under the instrument panel.

Maintenance and service
11-8
Engine compartment overview 2.5 liter model
1) Manual transmission oil level gauge
(MT) (page 11-25) or Differential
gear oil level gauge (AT) (page 11-29)
2) Air cleaner element (page 11-20)
3) Clutch fluid reservoir (page 11-35)
4) Automatic transmission fluid level gauge (page 11-27)
5) Brake fluid reservoir (page 11-34)
6) Windshield washer tank (page
11-50)
7) Fuse box (page 11-56)
8) Battery (page 11-54)
9) Engine oil filler cap (page 11-10)
10) Engine coolant reservoir (page 11-16)
11) Radiator cap (page 11-16)
12) Engine oil level gauge (page 11-10)
13) Power steering fluid reservoir (page 11-32)