2004 JEEP GRAND CHEROKEE spark plugs replace

MAINTAINING YOUR VEHICLE
CONTENTS
m4.0L Engine...........................251
m4.7L/4.7 HO Engine.....................252
mOnboard Diagnostic System Ð OBD II........253
mEmissions Inspection And Maintenance
Programs............................254
mReplacement Parts......................255
mDealer Service.........................255
mMaintenance Procedures..................256
NEngine Oil..........................256NDrive Belts - Check Condition And Tension . . . 261
NSpark Plugs.........................261
NCatalytic Converter....................261
NCrankcase Emission Control System........263
NFuel Filter..........................263
NAir Cleaner Filter.....................264
NMaintenance-Free Battery................264
NAir Conditioner Maintenance.............265
NPower Steering Fluid Check..............266
7

Drive Belts - Check Condition and Tension
At the mileages shown in the appropriate ªMaintenance
Schedule,º check all drive belts for condition and proper
tension. Improper belt tension can cause belt slippage
and failure.
Inspect the drive belt for evidence of cuts, cracks, or
glazing and replace them if there is any sign of damage
which could result in belt failure. If adjustment is re-
quired, adjust the belts according to the specifications
and procedures shown in the Service Manual.
Special tools are required to properly measure tension
and to restore belt tension to factory specifications. Also,
check belt routing to make sure there is no interference
between the belts and other engine components.
Spark Plugs
Spark plugs must fire properly to assure engine perfor-
mance and emission control. New spark plugs should be
installed at the specified mileage. The entire set should be
replaced if there is any malfunction due to a faulty spark
plug. Refer to the ªVehicle Emission Control Informa-
tionº label in the engine compartment for spark plug
information.
Catalytic Converter
The catalytic converter requires the use of unleaded fuel
only. Leaded gasoline will destroy the effectiveness of the
converter as an emission control device.
Under normal operating conditions, the catalytic con-
verter will not require maintenance. However, it is im-
portant to keep the engine properly tuned to assure
proper catalyst operation and prevent possible catalyst
damage.
MAINTAINING YOUR VEHICLE 261
7

Miles 18,000 21,000 24,000 27,000 30,000
(Kilometers) (29 000) (34 000) (38 000) (43 000) (48 000)
Change the engine oil and engine oil filter. X X X X X
Inspect the engine air cleaner filter, replace if nec-
essary.X
Inspect the PCV Valve, replace if necessary.LX
Replace the spark plugs.X
Lubricate the upper knuckle ball stud at steering &
suspension ball joints.XXX
Drain and refill the front and rear axles. X
Inspect the brake linings. X
Clean and lubricate the brake caliper pins. X
Drain and refill the automatic transmission fluid,
and change filter (4.0L Only).X
Drain and refill the automatic transmission fluid,
and replace main sump filter (4.7L Only).X
Drain the transfer case and refill (Quadra-Trac
Models Only).X
SCHEDULE ªBº 301
8
M
A
I
N
T
E
N
A
N
C
E
S
C
H
E
D
U
L
E
S

Miles 48,000 51,000 54,000 57,000 60,000
(Kilometers) (77 000) (82 000) (86 000) (91 000) (96 000)
Change the engine oil and engine oil filter. X X X X X
Inspect the engine air cleaner filter, replace if necessary.X
Inspect the PCV Valve, replace if necessary.LX
Replace the spark plugs.X
Lubricate the upper knuckle ball stud at steering & sus-
pension ball joints.XXX
Clean and lubricate brake caliper pins. X X
Inspect the brake linings. X X
Drain and refill the front and rear axles. X X
Drain and refill the automatic transmission fluid, and
change filter (4.0L Only).X
Drain and refill the automatic transmission fluid, and
replace main sump filter (4.7L Only).X
Inspect the drive belt and replace as needed. Not re-
quired if belt was previously replaced (4.0L Only).X
Drain and refill the transfer case fluid (Selec-Trac and
Quadra-Trac Models).X
SCHEDULE ªBº 303
8
M
A
I
N
T
E
N
A
N
C
E
S
C
H
E
D
U
L
E
S

Miles 78,000 81,000 84,000 87,000 90,000
(Kilometers) (125 000) (130 000) (134 000) (139 000) (144 000)
Change the engine oil and engine oil filter. X X X X X
Inspect the engine air cleaner filter, replace if nec-
essary.X
Inspect the PCV Valve, replace if necessary.LX
Replace the spark plugs.X
Lubricate the upper knuckle ball stud at steering &
suspension ball joints.XXX
Drain and refill the transfer case fluid (Quadra-Trac
Models Only).X
Inspect the brake linings. X
Clean and lubricate the brake caliper pins. X
Drain and refill the front and rear axle fluid. X
Drain and refill the automatic transmission fluid,
and change filter (4.0L Only).X
SCHEDULE ªBº 305
8
M
A
I
N
T
E
N
A
N
C
E
S
C
H
E
D
U
L
E
S

Miles 108,000 111,000 114,000 117,000 120,000
(Kilometers) (173 000) (178 000) (182 000) (187 000) (192 000)
Change the engine oil and engine oil filter. X X X X X
Inspect the engine air cleaner filter, replace if nec-
essary.X
Inspect the PCV Valve, replace if necessary.LX
Replace the spark plugs.X
Lubricate the upper knuckle ball stud at steering &
suspension ball joints.XXX
Inspect the brake linings. X X
Clean and lubricate the brake caliper pins. X X
Drain and refill the front and rear axle fluid. X X
Drain and refill the automatic transmission fluid,
and change filter (4.0L Only).X
Drain and refill the automatic transmission fluid,
and replace main sump filter (4.7L Only).X
308 SCHEDULE ªBº
8
M
A
I
N
T
E
N
A
N
C
E
S
C
H
E
D
U
L
E
S

Schedule ªAº
Miles 6,000 12,000 18,000 24,000 30,000
(Kilometers) (10 000) (19 000) (29 000) (38 000) (48 000)
[Months] [6] [12] [18] [24] [30]
Change the engine oil and engine oil filter. X X X X X
Inspect the engine air cleaner filter, and replace if
necessary.X
Replace the spark plugs.X
Lubricate the upper knuckle ball stud at steering &
suspension ball joints.XX
Inspect the brake linings. X
Clean and lubricate the brake caliper pins. X
Inspect transfer case fluid (Selec-Trac Models Only). X
Drain the transfer case and refill (Quadra-Trac
Models Only).X
310 SCHEDULE ªAº
8
M
A
I
N
T
E
N
A
N
C
E
S
C
H
E
D
U
L
E
S

Miles 60,000 66,000 72,000 78,000
(Kilometers) (96 000) (106 000) (115 000) (125 000)
[Months] [60] [66] [72] [78]
Change the engine oil and engine oil filter. X X X X
Inspect the engine air cleaner filter, and replace if nec-
essary.X
Inspect the PCV Valve, replace if necessary.LX
Replace the spark plugs.X
Lubricate the upper knuckle ball stud at steering & sus-
pension ball joints.XX
Inspect and replace the drive belt if necessary (4.0L
Only). Not required if belt was previously replaced.XX
Flush and replace the engine coolant. X
Inspect the brake linings. X
Clean and lubricate the brake caliper pins. X
Inspect transfer case fluid (Selec-Trac Models Only). X
Drain the transfer case and refill (Quadra-Trac Models
Only).X
312 SCHEDULE ªAº
8
M
A
I
N
T
E
N
A
N
C
E
S
C
H
E
D
U
L
E
S