2003 NISSAN SENTRA engine

2. Check the fluid level in each cell. If it is
necessary to add fluid , add only distilled
water to bring the level up to the bottom of
the filler opening.Do not overfill.Vehicles operated in high temperatures or under
severe conditions require frequent checks of the
battery fluid level.
JUMP STARTING
If jump starting is necessary, see “Jump starting”
in the “In case of emergency” section of this
manual. If the engine does not start by jump
starting, the battery may have to be replaced.
Contact a NISSAN dealer.
1. Power steering oil pump
2. Water pump
3. Idler pulley
4. Generator
5. A/C compressor
6. Crankshaft pulley
: Tension checking points
WARNING
Be sure the ignition key is in the OFF or
LOCK position. The engine could rotate
unexpectedly.
LDI0302
QG18DE engine
WDI0191
DRIVE BELTS
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1. Visually inspect each belt for signs of un-
usual wear, cuts, fraying or looseness. If the
belt is in poor condition or is loose, have it
replaced or adjusted by a NISSAN dealer.
2. Have the belts checked regularly for condi-
tion and tension in accordance with the
maintenance schedule found in the
“NISSAN Service and Maintenance Guide”.
1. Power steering fluid pump
2. Water pump
3. Generator
4. A/C compressor
5. Crankshaft pulley
6. Auto tensionerREPLACING SPARK PLUGS
WARNING
Be sure the engine and ignition switch are
off and that the parking brake is engaged
securely.
CAUTION
Be sure to use the correct socket to re-
move the spark plugs. An incorrect socket
can damage the spark plugs.
QR25DE engine
WDI0192WDI0193
SPARK PLUGS
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Platinum-tipped spark plugs
It is not necessary to replace platinum-tipped
spark plugs as frequently as conventional type
spark plugs because they last much longer. Fol-
low the maintenance schedule, but do not reuse
the spark plugs by cleaning or regapping.
cAlways replace spark plugs with recom-
mended or equivalent ones.
1. Remove the engine cover.
2. Disconnect the ignition coil connectors. Re-
move the ignition coil bolts.
3. Disconnect the spark plug cables from the
spark plugs.When disconnecting, always hold
the boots — not the cables. Mark all
cables to identify their original loca-
tions.
4. Remove the spark plugs with a spark plug
socket.
The plug socket has a rubber seal that holds
the spark plug so it does not fall when it is
pulled out. Make sure each spark plug is
snugly fitted into the spark plug socket.
5. Fit the new plugs, one at a time, into the
spark plug socket and install them.Use
only the specified spark plugs.Turn
each plug several full turns by hand, then
tighten with the spark plug socket to the
correct torque. Do not overtighten.
Spark plug tightening torque:
14 - 22 ft-lb (20 - 29 N·m)
6. Holding the boot, reconnect each high ten-
sion cable to its proper spark plug by push-
ing it on until you feel a snap.
7. Iinstall the ignition coil bolts.
Ignition coil bolt tightening torque:
33 - 44 in-lb (3.8 - 5.0 N·m)
Connect the ignition coil connector.
8. Install the engine cover.The air cleaner filter should not be cleaned and
reused. Replace it according to the maintenance
intervals shown in the “NISSAN Service and
Maintenance Guide.” When replacing the filter,
wipe the inside of the air cleaner filter housing
and the cover with a damp cloth.
WDI0005ADI0631
AIR CLEANER
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WARNING
cOperating the engine with the air
cleaner removed can cause you or oth-
ers to be burned. The air cleaner not
only cleans the air, it stops the flame if
the engine backfires. If it isn’t there, and
the engine backfires, you could be
burned. Do not drive with the air cleaner
removed, and be careful when working
on the engine with the air cleaner
removed.
cNever pour fuel into the throttle body or
attempt to start the engine with the air
cleaner removed. Doing so could result
in serious injury.
IN-CABIN MICROFILTER (if so
equipped)
The in-cabin microfilter restricts the entry of air-
borne dust and pollen particles and reduces
some objectionable outside odors. The filter is
located behind the glove box. Refer to the
“NISSAN Service and Maintenance Guide” for
change intervals.
To change the filter, perform the following proce-
dure:1. Remove the glove box door by removing the
two lower hinge pins.2. Remove the two screws securing the glove
box frame.
3. Remove the two screws securing the glove
box door latch. Remove the latch by pulling it
down.
4. Remove the glove box frame by pulling it
away from the instrument panel to disen-
gage the retaining clips.
LDI0139LDI0140
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If you wax the surface of the hood, be careful not
to let wax get into the washer nozzle
s1. This may
cause clogging or improper windshield washer
operation. If wax gets into the nozzle, remove it
with a needle or small pin
s2.
CHECKING PARKING BRAKE
From the released position, pull the parking brake
lever up slowly and firmly. If the number of clicks is
out of the range listed, see a NISSAN dealer.
c6 - 7 clicks under pulling force of 44 lb (196
N) .
CHECKING BRAKE PEDAL
With the engine running, check the distanceA
between the upper surface of the pedal and the
metal floor. If it is out of the range shown, see a
NISSAN dealer.
Distance A: under depressing force of 110
lb (490 N)
Automatic
TransmissionManual
Transmission
3 1/2 in (90 mm) or more
WDI0195
WDI0196WDI0197
PARKING BRAKE AND BRAKE PEDAL
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Self-adjusting brakes
Your vehicle is equipped with self-adjusting
brakes.
The front (and rear, if so equipped) disc-type
brakes self-adjust every time the brake pedal is
applied. The rear drum-type brakes also self-
adjust every time the brake pedal is applied.
If the brake pedal goes down farther than normal,
it may be due to a lack of adjustment of the rear
drum brakes. To adjust, apply the parking brake
several times.
WARNING
See a NISSAN dealer for a brake system
check if the brake pedal height does not
return to normal.
Brake pad wear indicators
The disc brake pads on your vehicle have audible
wear indicators. When a brake pad requires re-
placement, a high pitched scraping or screech-
ing sound will be heard when the vehicle is in
motion. The noise will be heard whether or not the
brake pedal is depressed. Have the brakes
checked as soon as possible if the wear indicator
sound is heard.
Under some driving or climate conditions, occa-
sional brake squeak, squeal or other noise maybe heard. Occasional brake noise during light to
moderate stops is normal and does not affect the
function or performance of the brake system.
The rear drum brakes (if so equipped) do not
have audible wear indicators. Should you ever
hear an unusually loud noise from the rear drum
brakes, have them inspected as soon as possible
by a NISSAN dealer.
Proper brake inspection intervals should
be followed.For more information regarding
brake inspections, see the appropriate mainte-
nance schedule information in the “NISSAN Ser-
vice and Maintenance Guide”.
BRAKE BOOSTER
Check the brake booster function as follows:
1. With the engine off, press and release the
brake pedal several times. When brake
pedal movement (distance of travel) remains
the same from one pedal application to the
next, continue on to the next step.
2. While depressing the brake pedal, start the
engine. The pedal height should drop a little.
3. With the brake pedal depressed, stop the
engine. Keep the pedal depressed for about
30 seconds. The pedal height should not
change.4. Run the engine for one minute without de-
pressing the brake pedal, then turn it off.
Depress the brake pedal several times. The
pedal travel distance will decrease gradually
with each depression as the vacuum is re-
leased from the booster.
If the brakes do not operate properly, have the
brakes checked by a NISSAN dealer.
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ENGINE COMPARTMENT
CAUTION
Never use a fuse of a higher amperage
rating than specified on the fuse box
cover. This could damage the electrical
system or cause a fire.
If any electrical equipment does not come on,
check for an open fuse.
1. Be sure the ignition switch and the headlight
switch are OFF.
2. Open the engine hood.3. Remove the fuse box cover by pushing the
tab and lifting the cover up.
4. Remove the fuse with the fuse puller. The
fuse puller is located in the center of the fuse
block in the passenger compartment.
5. If the fuse is open, replace it with a new fuse.
6. If a new fuse also opens, have the electrical
system checked and repaired by a NISSAN
dealer.
Fusible links
If the electrical equipment does not operate and
fuses are in good condition, check the fusible
links. If any of these fusible links are melted,
replace with only genuine NISSAN parts.
WDI0199WDI0200
FUSES
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HEADLIGHTS
The headlight is a semi-sealed beam type which
uses a replaceable headlight (halogen) bulb. A
bulb can be replaced from inside the engine
compartment without removing the headlight as-
sembly.
CAUTION
cHigh pressure halogen gas is sealed
inside the halogen bulb. The bulb may
break if the glass envelope is scratched
or the bulb is dropped.
cWhen handling the bulb, do not touch
the glass envelope.
cDO NOT TOUCH THE BULB
cUse the same number and wattage as
originally installed:
Wattage 65/55Bulb No. HB5/9007*
*: Always check with the Parts Depart-
ment at a NISSAN dealer for the latest
parts information.
cDo not leave the bulb out of the head-
light reflector for a long period of time
as dust, moisture and smoke may enter
the headlight body and affect the per-
formance of the headlight.cAiming is not necessary after replacing
the bulb. When aiming adjustment is
necessary, contact a NISSAN dealer.
WDI0202
LIGHTS
8-34Maintenance and do-it-yourself
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