2008 JEEP GRAND CHEROKEE spark plugs replace

MAINTAINING YOUR VEHICLE
CONTENTS
mEngine Compartment ± 6.1L...............306
mOnboard Diagnostic System Ð OBD II........307
NLoose Fuel Filler Cap Message............308
mEmissions Inspection And Maintenance
Programs............................308
mReplacement Parts......................310
mDealer Service.........................310
mMaintenance Procedures..................311
NEngine Oil..........................311NEngine Oil Filter......................315
NDrive Belts Ð Check Condition And
Tensioner...........................315
NSpark Plugs.........................316
NEngine Air Cleaner Filter................316
NFuel Filter..........................317
NCatalytic Converter....................317
NMaintenance-Free Battery................318
NAir Conditioner Maintenance.............319
7

At the mileage indicated on the appropriate ªMainte-
nance Schedule,º all belts and tensioner should be
checked for condition. Improper belt tension can cause
belt slippage and failure.
Belts should be inspected for evidence of cuts, cracks,
glazing, or frayed cords and replaced if there is indication
of damage which could result in belt failure. Low gen-
erator belt tension can cause battery failure.
Also check belt routing to make sure there is no interfer-
ence 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 ªFluids, Lubricants, and Genuine Partsº in
this section for spark plug information.
Engine Air Cleaner Filter
Under normal driving conditions, replace the air filter at
the intervals shown on ªMaintenance Schedule A.º If,
however, you drive the vehicle frequently under dusty or
severe conditions, the filter element should be inspected
periodically and replaced if necessary at the intervals
shown on ªMaintenance Schedule B.º
WARNING!
The air cleaner can provide a measure of protection
in the case of engine backfire. Do not remove the air
cleaner unless such removal is necessary for repair or
maintenance. Make sure that no one is near the
engine compartment before starting the vehicle with
the air cleaner removed. Failure to do so can result in
serious personal injury.
316 MAINTAINING YOUR VEHICLE

Miles 93,000 96,000 99,000 102,000 105,000
(Kilometers) (155 000) (160 000) (165 000) (170 000) (175 000)
Change the engine oil and engine oil filter, if not
replaced at 3 months.X X XXX
Inspect the engine air cleaner filter, replace if nec-
essary.X
Replace the spark plugs.X
Inspect the drive belt, replace if necessary.* X
Inspect the brake linings. X
Drain and refill the front and rear axle fluid. X
Flush and replace the engine coolant/anti-freeze, if
not done at 60 months.X
366 SCHEDULE ªBº
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Miles 84,000 90,000 96,000 102, 000
(Kilometers) (140 000) (150 000) (160 000) (170 000)
[Months] [84] [90] [96] [102]
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
Inspect the drive belt, replace if necessary.* X
Inspect the brake linings. X
Flush and replace the engine coolant/anti-freeze if not
replaced at 60 months.X
Drain the transfer case and refill. X
372 SCHEDULE ªAº
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