2003 SUBARU IMPREZA WRX engine

Maintenance and service
11-18
WARNING
Never attempt to remove the radiator cap until the engine has been shut off and has cooled
down completely. Since the coolant is underpressure, you may suffer serious burns from a
spray of boiling hot coolant when the cap is removed.
4. Install the under cover.
Non-turbo models
1) Filler neck
2) Fill up to this level
Turbo models
1) Filler neck
2) Fill up to this level
5. Slowly pour the coolant and fill to the radiator fill-
er neck. Do not pour the coolant too quickly, as this
may lead to insufficient air bleeding and trapped airin the system.

Maintenance and service
11-19
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Guideline of coolant quantity (including coolant in reser- voir tank):
Non-turbo models: MT. 7.4 US qt (7.0 liters, 6.2 Imp qt)
AT. 7.3 US qt (6.9 liters, 6.1 Imp qt)
Turbo models: MT. 8.1 US qt (7.7 liters, 6.8 Imp qt)
AT. 8.0 US qt (7.6 liters, 6.7 Imp qt)
1) “FULL” level mark
2) “LOW” level mark
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. Do not splash the engine coolant over
painted parts. The alcohol contained in the en-gine coolant may damage the paint surface.
6. Pour the coolant and fill to the reservoir tank ’s
“FULL” level mark.
1) Rubber gaskets
7. Put the radiator cap back on and tighten firmly. At

Maintenance and service
11-20
this time, make sure that the rubber gasket in the ra-
diator cap is correctly in place.
8. Start and run the engine for more than five min-utes at 2,000 to 3,000 rpm.
9. Stop the engine and wait until the coolant coolsdown (122 to 140°F [50 to 60 °C]). If there is any loss
of coolant, add coolant to the radiator ’s filler neck
and to the reserve tank ’s “FULL” level.
10. Put the radiator cap and reservoir cap back on
and tighten firmly. Air cleaner element
The air cleaner element functions as a filter screen.
When the element is perforated or removed, engine
wear will be excessive and engine life shortened.
The air cleaner element is a viscous type. It is un-
necessary to clean or wash the element.
WARNING
Do not operate the engine with the air cleaner
element removed. The air cleaner element notonly filters intake air but also stops flames ifthe engine backfires. If the air cleaner elementis not installed when the engine backfires, youcould be burned.
Replacing the air cleaner element
Non-turbo models
Replace the air cleaner element according to the
maintenance schedule in the “Warranty and Mainte-
nance Booklet ”. Under extremely dusty conditions,
replace it more frequently. It is recommended that
you always use genuine SUBARU parts.

Maintenance and service
11-26
Turbo model
Check the oil level monthly.
1. Park the vehicle on a level surface and stop theengine.
2. Pull out the dipstick, wipe it clean, and insert itagain.1) Upper level 2) Lower level
3. Pull out the dipstick again and check the oil level
on it. If it is below the lower level, add oil through thedipstick hole to bring the level up to the upper level. Recommended grade and viscosity
Each oil manufacturer has its own base oils and ad-
ditives. Never use different brands together.
Oil grade: API classification GL-5

Maintenance and service
11-27
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SAE viscosity No. and Applicable Temperature Automatic transmission fluid
Checking the fluid level
The automatic transmission fluid expands largely as
its temperature rises; the fluid level differs according
to fluid temperature. Therefore, there are two differ-ent scales for checking the level of hot fluid andcold fluid on the dipstick.
Though the fluid level can be checked without
warming up the fluid on the “COLD” range, we rec-
ommend checking the fluid level when the fluid is at
operating temperature.
Checking the fluid level when the fluid is hot
Check the fluid level monthly.
1. Drive the vehicle several miles to raise the tem-
perature of the transmission fluid up to normal oper-
ating temperature; 158 to 176 °F (70 to 80 °C) is nor-
mal.
2. Park the vehicle on a level surface and set theparking brake.
3. First shift the selector lever in each position. Then shift it in the “P” position, and run the engine at id-
ling speed.

Maintenance and service
11-29
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Recommended fluid
“ Dexron III ” Type Automatic Transmission FluidFront differential gear oil
(AT vehicles) Checking the oil level
1) Yellow handle
Check the differential oil level monthly.
1. Park the vehicle on a level surface and stop the engine.
2. Pull out the dipstick, wipe it clean, and insert itagain.

Maintenance and service
11-32
Recommended grade and viscosity
Each oil manufacturer has its own base oils and ad-
ditives. Never use different brands together.
Oil grade: API classification GL-5
SAE viscosity No. and Applicable Temperature Power steering fluid
Checking the fluid level
1) Reservoir tank
The power steering fluid expands greatly as its tem-
perature rises; the fluid level differs according to
fluid temperature. Therefore, the reservoir tank has
two different checking ranges for hot and coldfluids.
Check the power steering fluid level monthly.
1. Park the vehicle on a level surface, and stop theengine.

Maintenance and service
11-36
have the vehicle checked at your SUBARU
dealer.Never use different brands of clutch fluid to-
gether. When clutch fluid is added, be careful not to
allow any dirt into the tank.
Recommended clutch fluid
FMVSS No. 116, fresh DOT 3 or 4 brake fluidBrake booster If the brake booster does not operate as described
below, have it checked by your SUBARU dealer.
1. With the engine off, depress the brake pedal sev-
eral times, applying the same pedal force each time.
The distance the pedal travels should not vary.
2. With the brake pedal depressed, start the en-
gine. 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 about one min-
ute then turn it off. Depress the brake pedal several
times to check the brake booster. Brake booster op-
erates properly if the pedal stroke decreases with
each depression.