2003 SUBARU IMPREZA service

Maintenance and service
11-24
CAUTION
When disconnecting the spark plug cables,
always grasp the spark plug cap, not the cables. Make sure the cables are replaced in the
correct order.
Recommended spark plugs
Non-turbo models: RC10YC4 (Champion) BKR6E-11 (NGK)
BKR5E-11 (NGK)
Turbo models: PFR6G (NGK)
Drive belts
1) Power steering pump pulley
2) Air conditioner compressor pulley
3) Crank pulley
The alternator, power steering pump, and air condi-
tioner compressor depend on drive belts. Satisfacto-
ry performance requires that belt tension be correct.
To check belt tension, place a straightedge (ruler)
across two adjacent pulleys and apply a force of 22 lb (98 N, 10 kg) midway between the pulleys by us- ing a spring scale. Belt deflection should be the
amount specified. If a belt is loose, cracked, or

Maintenance and service
11-25
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worn, contact your SUBARU dealer.
in (mm)
Deflection
New beltUsed belt
A0.28 — 0.35
(7.0 — 9.0)0.35 — 0.43
(9.0 — 11.0)
B0.30 — 0.33
(7.5 — 8.5)0.35 — 0.40
(9.0 — 10.0)
Manual transmission oil Checking the oil level
Non-turbo model
1) Yellow handle

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
11-28
1) Yellow handleA) HOT range
B) COLD range1) Upper level
2) Lower level
4. Pull out the dipstick and check the fluid level on the gauge. If it is below the lower level on the “HOT”
range, add the recommended automatic transmis- sion fluid up to the upper level.
Checking the fluid level when the fluid is cold
When the fluid level has to be checked without time
to warm up the automatic transmission, check tosee that the fluid level is between the lower leveland upper level on the “COLD” range. If it is below
that range, add fluid up to the upper level. Be care-
ful not to overfill.

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
11-30
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 to bring thelevel 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-5SAE viscosity No. and Applicable Temperature

Maintenance and service
11-31
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Rear differential gear oil Checking the gear oil level
Your vehicle may be equipped with a rear differential
protector. The differential protector provides protec-
tion to the rear differential assembly during off-road
use. Removal of the rear differential protector is not
required when checking the oil level.
1) Filler plug 2) Drain plug
1) Filler hole
2) Drain hole 3) Oil level
Remove the plug from the filler hole and check the oil level. The oil level should be kept even with thebottom of the filler hole. If the oil level is below the
bottom edge of the hole, add oil through the filler
hole to raise the level.
CAUTION
If the vehicle requires frequent refilling, there
may be an oil leak. If you suspect a problem,
have the vehicle checked at your SUBARU
dealer.