Preliminary Checks - Jeep cherokee 2000 Service Manual

XJ
DIAGNOSIS AND TESTING (Continued)
CONDITION
NOISE (Objectionable squeal,
squeak, or rumble is heard or felt
while drive belt is in operation)
TENSION SHEETING FABRIC
FAILURE
(Woven fabric on outside,
circumference of belt has cracked or
separated from body of belt)
CORD EDGE FAILURE
(Tensile member exposed at edges
of belt or separated from belt body)

PRELIMINARY CHECKS

ENGINE COOLING SYSTEM OVERHEATING
Establish what driving conditions caused the com-
plaint. Abnormal loads on the cooling system such as
the following may be the cause:
PROLONGED IDLE, VERY HIGH AMBIENT TEMPERATURE,
SLIGHT TAIL WIND AT IDLE, SLOW TRAFFIC, TRAFFIC
JAMS, HIGH SPEED OR STEEP GRADES.
Driving techniques that avoid overheating are:
• Idle with A/C off when temperature gauge is at
end of normal range.
• Increasing engine speed for more air flow is rec-
ommended.
TRAILER TOWING:
Consult Trailer Towing section of owners manual.
Do not exceed limits.
AIR CONDITIONING; ADD-ON OR AFTER MARKET:
A maximum cooling package should have been
ordered with vehicle if add-on or after market A/C is
installed. If not, maximum cooling system compo-
nents should be installed for model involved per
manufacturer's specifications.
POSSIBLE CAUSES
1. Belt slippage
2. Bearing noise
3. Belt misalignment
4. Belt to pulley mismatch
5. Driven component induced
vibration
6. System resonant frequency
induced vibration
1. Tension sheeting contacting
stationary object
2. Excessive heat causing woven
fabric to age
3. Tension sheeting splice has
fractured
1. Excessive tension
2. Belt contacting stationary object
3. Pulley(s) out of tolerance
4. Insufficient adhesion between
tensile member and rubber matrix
RECENT SERVICE OR ACCIDENT REPAIR:
Determine if any recent service has been per-
formed on vehicle that may effect cooling system.
This may be:
• Engine adjustments (incorrect timing)
• Slipping engine accessory drive belt(s)
• Brakes (possibly dragging)
• Changed parts. Incorrect water pump or pump
rotating in wrong direction due to belt not correctly
routed
• Reconditioned radiator or cooling system refill-
ing (possibly under filled or air trapped in system).
NOTE: If investigation reveals none of the previous
items as a cause for an engine overheating com-
plaint, refer to following Cooling System Diagnosis
charts.
These charts are to be used as a quick-reference
only. Refer to the group text for information.
COOLING SYSTEM
CORRECTION
1. Adjust belt tension (2.5L)
2. Locate and repair
3. Align belt/pulley(s)
4. Install correct belt
5. Locate defective driven
component and repair
6. Vary belt tension within
specifications.
1. Correct rubbing condition
2. Replace belt
3. Replace belt
1. Adjust belt tension (2.5L)
2. Replace belt
3. Replace pulley
4. Replace belt and adjust tension
to specifications
7 - 11