2004 SUBARU IMPREZA engine

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Maintenance and service
2.5-liter and 2.0-liter turbo models
1) Notch
2) Upper level
3) Lower level
4. Pull out the dipstick 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.
" Use only engine oil with the recommended
grade and viscosity. " 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 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 en-
gine oil level reading may be in a range between the
upper level and the notch mark. This is caused by ther-
mal expansion of the engine oil.
To prevent overfilling the engine oil, do not add any
additional oil above the upper level when the engine iscold. ! Changing the oil and oil filter
Change the oil and oil filter according to the mainte-
nance schedule in the “Warranty and Maintenance Booklet”.
The engine oil and oil filter must be changed more fre-
quently than listed in the maintenance schedule when
driving on dusty roads, when short trips are frequently
made, or when driving in extremely cold whether.
1. Warm up the engine by letting the engine idle for
about 10 minutes to ease draining the engine oil.
2. Park the vehicle on a level surface and stop the en-
gine.
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3
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Maintenance and service
Non-turbo models
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.
Be careful not to burn yourself with hot engineoil.
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 under cover (For turbo).
Turbo models
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Maintenance and service
– CONTINUED –
Non-turbo models
7. 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 lower
crank case/oil cooler (For Turbo) and install the oil fil-
ter by hand turning. Be careful not to twist or damage
the seal.
10.Tighten it approximately two-thirds of a turn after
the seal makes contact with the lower crank case/oil
cooler (For Turbo).
Never over tighten the oil filter because that canresult in an oil leak.
11.Reinstall under cover (For Turbo).
12.Pour engine oil through the filler neck.
Oil capacity (guideline): Non-turbo models: 4.2 US qt (4.0 liters, 3.5 Imp qt)
Turbo models:
4.8 US qt (4.5 liters, 4.0 Imp qt)
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 the dipstick to con-
firm that the level is correct.
13.Start the engine and make sure that no oil leaks ap-
pear around the filter’s rubber seal and drain plug.
14.Run the engine until it reaches the normal operat-
ing temperature. Then stop the engine and wait a few
minutes to allow the oil drain back. Check the oil level
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Maintenance and service
again and if necessary, add more engine oil.
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
Oil grade:
ILSAC GF-3, which can be identified with the new
API certification mark (Starburst mark)
or API classification SL with the words “ENERGY
CONSERVING” (if you cannot obtain the oil with
SL grade, you may use SJ grade “ENERGY CON-
SERVING” oil).
These recommended oil grades can be identified by
looking for either or both of the following marks dis-
played on the oil container. API Service label
1) Indicates the oil quality by API designations
2) Indicates the SAE oil viscosity grade
3) Indicates that the oil has fuel saving capabilities
APISERVICESL
ENERGYCONSERVING
SAE
5W
30
1
2
3
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Maintenance and service
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New API Certification Mark (Starburst Mark)
In choosing an oil, you want the proper quality and vis-
cosity, as well as one that will add to fuel economy.
The following table lists the recommended viscosities
and applicable temperatures.
When adding oil, different brands may be used togeth-
er as long as they are the same API classification and
SAE viscosity as those recommended by SUBARU. SAE viscosity number and applicable temperature
*: 5W-30 is preferred.
Engine oil viscosity (thickness) affects fuel economy.
Oils of lower viscosity provide better fuel economy.
However, in hot weather, oil of higher viscosity is re-
quired to properly lubricate the engine.
Use only engine oil with the recommended
grade and viscosity.
AMERICANPETROLEUMINSTITUTE
CERTIFIED
HSB023AA
5W-30*
10W-30, 10W-40
-30 -20 -10 0 10 20 30 40
-20
06 0
20 80 100 40
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Maintenance and service
!
Recommended grade and viscosity
under severe driving conditions
If the vehicle is used in desert areas, in areas with very
high temperatures, or used for heavy-duty applica-
tions such as towing a trailer, use of oil with the follow-
ing grade and viscosities is recommended.
API classification SL (or SJ):
SAE viscosity No.: 30, 40, 10W-50, 20W-40, 20W-50
! Synthetic oil
You can use synthetic engine oil that meets the same
requirements given for conventional engine oil. When
using synthetic oil, you must use oil of the same clas-
sification, viscosity and grade shown in this owner’s
manual, and must follow the oil and filter changing in-
tervals shown in the maintenance schedule.
Cooling system
Never attempt to remove the radiator 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 boiling hot coolant when the cap is re-
moved.
" The cooling system has been filled at the fac-
tory with a high quality, corrosion-inhibiting,
year-around coolant which provides protection
against freezing down to –33 °F (–36 °C). For
adding, use genuine SUBARU coolant or an
equivalent: a mixture of 50% soft water and 50%
ethylene-glycol basis coolant. Use of improper
coolants may result in corrosion in the cooling
system. It is important to maintain protection
against freezing and corrosion, even if freezing
temperatures are not expected. Never mix dif-
ferent kinds of coolant. " Do not splash the engine coolant over paint-

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Maintenance and service
– CONTINUED –
ed parts. The alcohol contained in the enginecoolant may damage the paint surface.
! Cooling fan, hose and connections
Your 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 engine coolant temperature gauge exceeds the
normal operating range, the cooling fan circuit may be
defective. Check the fuse and replace it if necessary.
If the fuse is not blown, have the cooling system
checked by your SUBARU dealer.
If frequent addition of coolant is necessary, there may
be a leak in the engine cooling system. It is recom-
mended 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 reser-
voir 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 re-
fill as required.
FULL
LOW
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Maintenance and service
1) Rubber gaskets
3. After refilling the reserve tank and the radiator, re-
install the caps and check that the rubber gaskets in-
side the radiator cap are in the proper position.
" 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 paint-
ed parts. The alcohol contained in the engine
coolant may damage the paint surface.
! Changing the coolant
1) Drain plug
Change the engine coolant using the following proce-
dures 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.
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1HSB027BB