2003 SUBARU IMPREZA WRX cooling

4
4-1
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Ventilator 4-2
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Air flow selection 4-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Center and side ventilators 4-3 . . . . . . . . . . . . . . . . . . . . . .
Climate control system 4-4 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Control panel 4-4
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Heater operation 4-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air conditioner operation (if equipped) 4-9 . . . . . . . .
Operating tips for heater and air
conditioner 4-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning ventilation grille 4-11 . . . . . . . . . . . . . . . . . . . . . . . .
Efficient cooling after parking in direct sunlight 4-11
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Lubrication oil circulation in the refrigerant
circuit 4-11
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Checking air conditioning system before summer season 4-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling and dehumidifying in high humidity and low temperature weather conditions 4-12 . . .
Air conditioner compressor shut-off when engine is heavily loaded 4-12 . . . . . . . . . . . . . . . . . . . . . . . .
Refrigerant for your climate control system 4-12 . .
Air filtration system (if equipped) 4-13 . . . . . . . . . . . . .
Climate control

Climate control
4-9
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To force outside air through the instrument panel outlets:
1. Set the air inlet selection lever to the “
”
position.
2. Set the air flow control dial to the “
” position.
3. Set the temperature control dial all the way left.
4. Set the fan speed control dial to the desired speed.
When driving on a dusty road, set the air inlet con-
trol lever to the “ON” position.
WARNING
Continued operation in the “” position
may fog up the windows. Switch to the “
” position as soon as the outside dusty
condition clears.
Air conditioner operation (if equipped)
Cooling or dehumidifying
1) ON position
For cooling and dehumidification of the passenger
compartment, air flows through the instrument paneloutlets:
1. Set the air inlet selection lever to the “
” posi-
tion.
2. Set the air flow control dial to the “
” position.
3. Set the air conditioner button to the “ON” posi-
tion.

Climate control
4-11
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Operating tips for heater and air conditioner Cleaning ventilation grille
Always keep the front ventilation inlet grille free of
snow, leaves, or other obstructions to ensure effi-
cient heating and defrosting. Since the condenser is
located in front of the radiator, this area should be
kept clean because cooling performance is im-
paired by any accumulation of insects and leaves
on the condenser.
Efficient cooling after parking in direct sunlight
After parking in direct sunlight, drive with the win- dows open for a few minutes to allow outside air to
circulate into the heated interior. This results in
quicker cooling by the air conditioner. Keep the win-dows closed during the operation of the air condi-
tioner for maximum cooling efficiency. Lubrication oil circulation in the refrigerant circuit
Operate the air conditioner compressor at a low en- gine speed (at idle or low driving speeds) a few
minutes each month during the off-season to circu-
late its oil. Checking air conditioning system before summer season
Check the air conditioner unit for refrigerant leaks,
hose conditions, and proper operation each spring.
This check is best performed by your SUBARU
dealer.

Climate control
4-12
Cooling and dehumidifying in high humidity and low temperatureweather conditions
Under certain weather conditions (high relative hu-
midity, low temperatures, etc.) a small amount of wa-
ter vapor emission from the air outlets may be not-
iced. This condition is normal and does not indicate
any problem with the air conditioning system. Air conditioner compressor shut-off when engine is heavily loaded
To improve acceleration and gas mileage, the air
conditioner compressor is designed to temporarily
shut off during air conditioner operation whenever
the accelerator is fully depressed such as duringrapid acceleration or when driving on a steepupgrade. Refrigerant for your climate control system
Your air conditioner uses ozone friendly refrigerant
HFC134a. Therefore, the method of adding, chang-
ing or checking the refrigerant is different from the
method for CFC12 (Freon). Consult your SUBARU
dealer for service. Repairs needed as a result of using the wrong refrigerant are not covered under
warranty.

In case of emergency
9-15
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Be sure the jumper cables and clamps on
them do not have loose or missing insulation.
Do not jump start unless cables in suitablecondition are available. 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.
When your vehicle does not start due to a run down
(discharged) battery, the vehicle may be jump
started by connecting your battery to another bat-
tery (called the booster battery) with jumper cables.
Jump starting is dangerous if it done incorrectly. If
you are unsure about the proper procedure for jump
starting, consult a competent mechanic.
How to jump start
1. Make sure the booster battery is 12 volts and the
negative terminal is grounded.
2. If the booster battery is in another vehicle, do notlet the two vehicles touch.
3. Turn off all unnecessary lights and accessories.
4. Connect the jumper cables exactly in the se-
quence illustrated.

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

11
11-1
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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
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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