Jeep Cherokee 1999 Electronic Service Manual page 1032

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DESCRIPTION AND OPERATION
ENGINE DESCRIPTION . . . . . . . . . . . . . . . . . . . 15
LUBRICATION SYSTEM . . . . . . . . . . . . . . . . . . . 16
OIL PUMP PRESSURE . . . . . . . . . . . . . . . . . . . . 18
SERVICE PROCEDURES
FITTING CONNECTING ROD BEARINGS . . . . . . 20
FITTING CRANKSHAFT MAIN BEARINGS . . . . . 23
PISTON FITTING . . . . . . . . . . . . . . . . . . . . . . . . 18
PISTON RING FITTING . . . . . . . . . . . . . . . . . . . 18
VALVE TIMING . . . . . . . . . . . . . . . . . . . . . . . . . . 18
REMOVAL AND INSTALLATION
CAMSHAFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
CAMSHAFT BEARINGS . . . . . . . . . . . . . . . . . . . 42
CAMSHAFT PIN REPLACEMENT . . . . . . . . . . . . 40
CRANKSHAFT MAIN BEARINGS . . . . . . . . . . . . 42
CYLINDER HEAD . . . . . . . . . . . . . . . . . . . . . . . . 33
CYLINDER HEAD . . . . . . . . . . . . . . . . . . . . . . . . 35
CYLINDER HEAD COVER . . . . . . . . . . . . . . . . . 31
ENGINE ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . 27
ENGINE MOUNTS—FRONT . . . . . . . . . . . . . . . . 26
ENGINE MOUNT—REAR . . . . . . . . . . . . . . . . . . 27
EXHAUST MANIFOLD—2.5L ENGINE . . . . . . . . . 30
HYDRAULIC TAPPETS . . . . . . . . . . . . . . . . . . . . 35
DESCRI PT I ON AN D OPERAT I ON
ENGINE DESCRIPTION
Th e 2.5 lit er (150 CID) fou r-cylin der en gin e is a n
In -lin e, ligh t weigh t , over h ea d va lve en gin e.
Th is en gin e is design ed for u n lea ded fu el. Th e
en gin e cylin der h ea d h a s du a l qu en ch -t ype com bu s-
t ion ch a m ber s t h a t cr ea t e t u r bu len ce a n d fa st bu r n -
in g of t h e a ir /fu el m ixt u r e. Th is r esu lt s in good fu el
econ om y.
Th e cylin der s a r e n u m ber ed 1 t h r ou gh 4 fr om fr on t
t o r ea r. Th e fir in g or der is 1-3-4-2 (F ig. 1).
Th e cr a n ksh a ft r ot a t ion is clockwise, wh en viewed
fr om t h e fr on t of t h e en gin e. Th e cr a n ksh a ft r ot a t es
wit h in five m a in bea r in gs a n d t h e ca m sh a ft r ot a t es
wit h in fou r bea r in gs.
2 .5 L EN GI N E
INDEX
page
INTAKE MANIFOLD—2.5L ENGINE . . . . . . . . . . 29
OIL PAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
OIL PUMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
PISTONS AND CONNECTING RODS . . . . . . . . . 46
REAR MAIN OIL SEALS . . . . . . . . . . . . . . . . . . . 47
ROCKER ARMS AND PUSH RODS . . . . . . . . . . 31
TIMING CASE COVER . . . . . . . . . . . . . . . . . . . . 37
TIMING CASE COVER OIL SEAL
TIMING CHAIN AND SPROCKETS . . . . . . . . . . . 38
VALVE SPRINGS AND OIL SEALS . . . . . . . . . . . 32
VIBRATION DAMPER . . . . . . . . . . . . . . . . . . . . . 36
DISASSEMBLY AND ASSEMBLY
CYLINDER BLOCK . . . . . . . . . . . . . . . . . . . . . . . 50
VALVE SERVICE . . . . . . . . . . . . . . . . . . . . . . . . 48
CLEANING AND INSPECTION
CYLINDER BLOCK . . . . . . . . . . . . . . . . . . . . . . . 51
ENGINE CYLINDER HEAD . . . . . . . . . . . . . . . . . 50
ROCKER ARMS AND PUSH RODS . . . . . . . . . . 50
SPECIFICATIONS
2.5L ENGINE SPECIFICATIONS . . . . . . . . . . . . . 52
2.5L TORQUE SPECIFICATIONS . . . . . . . . . . . . 54
SPECIAL TOOLS
2.5L ENGINE . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
2.5L ENGINE
Fig. 1 Engine Firing Order
9 - 15
page
. . . . . . . . . . . 36