1988 JEEP CHEROKEE drain bolt

Disconnect throttle valve linkage on A/T models.
3) Remove coolant temperature sensor wire. Disconnect
throttle cable at bellcrank. Remove intake manifold bolts. Remove
intake manifold.
4) If exhaust manifold requires removal, raise and support
vehicle. Disconnect exhaust pipe. Remove oxygen sensor wire and remove
sensor. Remove manifold-to-cylinder head bolts. Remove exhaust
manifold.
Installation
1) Ensure all gasket surfaces are clean. Install manifolds
and gasket on cylinder head. Start all bolts and finger tighten.
Tighten bolts in proper sequence. See Fig. 1. Tighten bolts to
specification. See TORQUE SPECIFICATIONS table.
2) Clean oxygen sensor threads. Apply anti-seize on oxygen
sensor threads prior to installation. Install sensor and tighten to
specification. Reverse removal procedures to complete installation.
Fill and purge cooling system. See COOLING SYSTEM AIR PURGE under
ENGINE COOLING.
Fig. 1: Manifold Bolt Tightening Sequence
CYLINDER HEAD
Removal
1) Disconnect negative battery cable. Drain cooling system.
Remove air cleaner. Remove intake and exhaust manifolds. See INTAKE &
EXHAUST MANIFOLDS.
2) Disconnect and mark all hoses and electrical connections
at cylinder head. Disconnect and mark spark plug wires. Remove spark
plugs. Remove valve cover bolts.

specification. Install front cover oil seal. See FRONT COVER OIL SEAL
Remove front cover seal installer.
4) Reverse removal procedures. Lubricate vibration damper
retaining bolt with oil prior to installation. Tighten bolts to
specification.
FRONT COVER OIL SEAL
Removal & Installation
1) Remove vibration damper. Using Seal Remover (J-9256),
remove seal from front cover. Position new seal on Front Cover Seal
Installer (J-22248) with lip facing outward.
2) Apply sealant to seal outer diameter. Lightly coat
crankshaft with oil. Place front cover seal installer on front of
crankshaft. Tap seal into front cover. Remove seal installer. Lightly
coat seal contact area of vibration damper with oil.
3) Install key in crankshaft (if removed). Install vibration\
damper. Lubricate vibration damper bolt with oil. Install retaining
bolt and washer. Tighten to specification.
CAMSHAFT & TIMING GEAR
Removal
1) Drain cooling system. Remove radiator. Remove engine front
cover. See ENGINE FRONT COVER. Remove distributor. Remove fuel pump
(if equipped with mechanical pump). Remove rocker arms and pushrods.
See ROCKER ARMS & BRIDGE under VALVES.
2) Remove valve lifters. Mark lifters for location. Remove
crankshaft oil slinger. Pull chain tensioner block toward tensioner
lever to compress spring. Hold block and move tensioner lever to lock
position. See Fig. 3.
3) Rotate crankshaft and align timing marks on crankshaft and
camshaft gears. Remove camshaft gear retaining bolt. Remove gears and
timing chain. Remove camshaft.
Fig. 3: Location of Chain Tensioner Lock
Courtesy of Chrysler Motors.
Inspection
Inspect camshaft for flaking, lobe wear or worn bearing

1) Drain cooling system. Remove fan shroud and drive belts.
Remove fan assembly.
2) Disconnect heater hoses and lower radiator hose at water
pump. Remove water pump retaining bolts. Remove water pump.
Installation
Clean all gasket surfaces. Install water pump. Tighten bolts
to specification. Ensure pump turns freely. Reverse removal
procedures. Fill and purge air from cooling system.
NOTE: It may be necessary to remove heater hose to remove trapped
air if system cannot be purged using following procedures.
Cooling System Air Purge (Vehicles With Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Install
coolant caps. Operate engine to normal operating temperature. Shut off
engine and allow system to cool. Add coolant to recovery bottle.
Repeat procedure to obtain correct coolant level.
Cooling System Air Purge (Vehicles Without Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Operate
engine to normal operating temperature with radiator cap removed. Add
necessary coolant and install radiator cap.
NOTE: For further information on cooling system capacities and
other cooling system components, see ENGINE COOLING SYSTEMS
article.
ENGINE OILING
CRANKCASE CAPACITY
Crankcase capacity is 4 qts. (3.8 L) with oil filter change.
NORMAL OIL PRESSURE
Normal oil pressure should be 13 psi (.91 kg/cm) at 600 RPM
or 37-75 psi (2.6-5.3 kg/cm) at 1600 RPM.
OIL PRESSURE REGULATOR VALVE
Oil pressure regulator valve is located in oil pump body and
is nonadjustable.
OILING SYSTEM
Engine lubrication is provided by the distributor driven
gear-type oil pump. Oil is supplied through the full-flow oil filter
and into an internal oil passage. Internal passage runs along right
side of block and intersects lifter bores.
Oil is then routed to camshaft and crankshaft bearings. Oil
is supplied to rocker arms from the hydraulic lifters and through the
push rods. By-pass valves are located in oil filter mounting and oil
pump.
OIL PUMP
Removal
Remove oil pan. See OIL PAN REMOVAL article. Remove oil pump

from intake manifold. Disconnect fuel lines at fuel rail. Fuel lines
are removed by squeezing the 2 retaining tabs against the fuel line
and pulling the fuel line from the connector. Use caution as these
fuel lines are under pressure.
3) Loosen drive belt tensioner and remove drive belt. Remove
power steering pump and bracket from intake manifold. Remove fuel rail
retaining bolts. Remove fuel rail and injector assembly.
4) Remove intake manifold heat shield. Disconnect EGR tube
fittings. Disconnect exhaust pipe from manifold. Disconnect oxygen
sensor. Remove retaining bolts and remove manifolds.
Installation
1) Install new gasket. Install exhaust and intake manifolds
and loosely install bolts. Install EGR tube between manifolds. Tighten
manifold bolts in proper sequence see Fig. 1. Tighten to
specifications, see TORQUE SPECIFICATIONS TABLE in this article.
2) Tighten EGR tube bolts. Apply anti-seize to oxygen sensor
threads prior to installation. Reverse removal procedures for
remaining components. Tighten bolts to specification.
3) Install new "O" rings on fuel line connectors prior to
installation. Ensure "CLICK" sound is heard when installing fuel
lines. This indicates that fuel lines are properly seated.
Fig. 1: Manifold Tightening Sequence (4.0L)
Courtesy of Chrysler Motors.
INTAKE & EXHAUST MANIFOLD (4.2L)
Removal
1) Remove air cleaner. Disconnect fuel line at carburetor.
Mark and disconnect all vacuum hoses, ventilation hoses and electrical
connectors at intake manifold.
2) Disconnect throttle cable at bellcrank. On A/T models,
disconnect throttle valve rod. On all models, remove PCV hose from
manifold. Drain cooling system. Remove coolant hoses from intake

manifold.
3) Remove EGR tube fittings from manifolds. Remove power
steering pump and A/C compressor and mounting brackets (if equipped).
4) Remove intake manifold bolts. Remove intake manifold. If
exhaust manifold requires removal, disconnect exhaust pipe from
manifold. Remove oxygen sensor (if equipped). Remove exhaust manifold.\
Installation
1) Install new gasket. Install exhaust manifold and loosely
install bolts. Install intake manifold. Tighten bolts to specification
in proper sequence. See Fig. 2.
2) Apply anti-seize to oxygen sensor threads prior to
installation. Reverse removal procedure for remaining components.
Tighten bolts to specification. Fill and purge cooling system. See
COOLING SYSTEM AIR PURGE under WATER PUMP in this article.
Fig. 2: Manifold Tightening Sequence (4.2L)
Courtesy of Chrysler Motors.
CYLINDER HEAD
Removal
1) Disconnect negative battery cable. Drain cooling system.
Disconnect hoses at thermostat housing. Remove intake and exhaust
manifolds. See the following:
* INTAKE & EXHAUST MANIFOLD (4.0L) .
* INTAKE & EXHAUST MANIFOLD (4.2L) .
2) Disconnect and mark all hoses and electrical connections
at cylinder head. Disconnect and mark spark plug wires. Remove spark
plugs. Remove valve cover bolts.
3) Remove the rocker arms and the push rods. Remove cylinder
head bolts. Remove cylinder head. See ROCKER ARMS & BRIDGE.
Inspection
Inspect cylinder head for cracks or damage. Using
straightedge, check cylinder head for warpage in several areas. Repair

care not to damage seal area. Position new seal on Front Cover Seal
Installer (J-22248) with lip facing outward.
2) Apply sealant to seal outer diameter. Lightly coat
crankshaft with oil. Place front cover seal installer on front of
crankshaft. Tap seal into front cover. Lightly coat seal contact area
of vibration damper with oil.
3) Install key in crankshaft (if removed). Install vibration\
damper. Lubricate vibration damper bolt with oil. Install retaining
bolt and washer. Tighten to specification.
TIMING CHAIN & SPROCKET
Removal
1) Drain cooling system. Remove radiator. Remove engine front
cover. See ENGINE FRONT COVER in this article. Remove oil slinger.
Rotate crankshaft until timing marks on sprockets are aligned. See
Fig. 4 .
2) Remove camshaft sprocket bolt. Remove timing chain and
both sprockets as an assembly.
Installation
Install timing chain and sprockets. Ensure timing marks are
aligned. See Fig. 4. Install camshaft sprocket bolt. Tighten bolts to
specification. Install new front cover oil seal. Reverse removal
procedure for remaining components.
Fig. 4: Timing Chain & Sprocket Alignment
Courtesy of Chrysler Motors.
CAMSHAFT

Removal
1) Drain cooling system. Remove radiator. Discharge A/C
system if necessary. Remove A/C condenser and receiver assembly (if
equipped). Remove fuel pump (if equipped with mechanical pump),
ignition wires and distributor.
2) Remove cylinder head. See CYLINDER HEAD in this article.
Remove hydraulic lifters. Using Lifter Remover/Installer (J-21884),
remove lifters. Mark lifter location for reassembly reference.
3) Remove engine front cover. See ENGINE FRONT COVER in this
article. Remove timing chain and sprockets. Remove front bumper and
grille (if necessary). Carefully remove camshaft.
Inspection
Inspect camshaft for flaking, lobe wear or worn bearing
journals. Replace if not within specification. See ENGINE
SPECIFICATIONS tables.
Installation
Lubricate camshaft and install into place. Use care not to
damage camshaft bearings. Reverse removal procedure to complete
installation. Tighten bolts to specification.
Camshaft Bearing
Replace camshaft bearings using camshaft bearing
remover/installer. Ensure oil holes are aligned after installation.
OIL PAN
See OIL PAN REMOVAL at end of ENGINE section.
PISTON & ROD
NOTE: Mark piston cylinder location for reassembly reference.
Install pistons in original cylinder location.
Removal
1) Remove cylinder head. See CYLINDER HEAD in this article.
Remove oil pan. See OIL PAN REMOVAL at end of ENGINE section. Remove
ridge or deposits from cylinder bore.
2) Mark connecting rod and piston for cylinder
identification. Remove bearing cap. Remove piston and rod assembly.
CAUTION: Arrows on top of piston must point toward front of engine.
Oil squirt holes in connecting rod must face camshaft side
of engine.
Installation
1) Ensure ring end gap and side clearance are within
specification. See ENGINE SPECIFICATIONS tables. Install rings on
piston. Position ring end gaps at specified areas. See Fig. 5. Ring
gaps may vary 20 degrees from positions illustrated.

Removal
Drain cooling system. Disconnect radiator and heater hoses
from pump. Remove drive belt(s). Remove fan shroud. Remove fan
assembly. Remove electric cooling fan (if equipped). Remove power
steering bracket from water pump. Remove water pump and gasket.
Installation
Ensure gasket surfaces are clean. Install water pump. Tighten
bolts to specification. Ensure pump turns freely. Reverse removal
procedures. Fill and purge air from cooling system.
NOTE: It may be necessary to remove heater hose to remove trapped
air if system cannot be purged using following procedures.
Cooling System Air Purge (Vehicles W/Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Install
coolant caps. Operate engine to normal operating temperature. Shut off
engine and allow system to cool. Add coolant to recovery bottle.
Repeat procedure to obtain correct coolant level.
Cooling System Air Purge (Vehicles W/O Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Operate
engine to normal operating temperature with radiator cap removed. Add
necessary coolant and install radiator cap.
NOTE: For further information on cooling systems, see appropriate
article in the ENGINE COOLING section.
LUBRICATION
CRANKCASE CAPACITY
Crankcase capacity for 4.0L is 5 1/2 qts. (5.2L) or 5 qts.
(4.7L) for 4.2L with oil filter change.
NORMAL OIL PRESSURE
Normal oil pressure should be 37-75 psi (2.6-5.3 kg/cm)
maximum above 1600 RPM. Minimum oil pressure should be 13 psi (.9
kg/cm
) at 600 RPM.
OIL PRESSURE REGULATOR VALVE
Oil pressure regulator valve is located in pump body. Valve
is nonadjustable and serviced as an assembly.
ENGINE OILING SYSTEM
Engine lubrication is provided by the distributor driven
gear-type oil pump. Oil is supplied through the full-flow oil filter
and into an internal oil passage. Internal passage provides oil to the
lifter bores. Oil is then routed to camshaft and crankshaft bearings.
Oil is supplied to rocker arms from the hydraulic lifters and through
the push rods.
OIL PUMP
Removal
Remove oil pan. See OIL PAN REMOVAL in this section. Remove