Jeep Wrangler TJ. Manual — part 427
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE
PRESSURE
BUILT
UP,
BY
CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester’s pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL - CYLINDER HEAD
(1) Perform fuel system pressure release procedure
before attempting any repairs. (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY - SPECIFICA-
TIONS)
(2) Disconnect battery negative cable.
(3) Drain cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(4) Remove air filter housing and inlet tube.
(5) Remove intake manifold.
(6) Remove heater tube support bracket from cyl-
inder head.
(7) Disconnect radiator upper and heater supply
hoses from water outlet connections.
(8) Remove accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY
DRIVE/DRIVE
BELTS
-
REMOVAL)
(9) Raise vehicle and remove exhaust pipe from
manifold.
(10) Remove power steering pump and set aside.
Do not disconnect lines.
(11) Remove accessory drive bracket
(12) Remove ignition coil and wires from engine.
(13) Disconnect cam sensor and fuel injector wir-
ing connectors.
(14) Remove timing belt and camshaft sprockets.
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT/CHAIN AND SPROCKETS - REMOVAL)
(15) Remove timing belt idler pulley and rear tim-
ing belt cover. (Refer to 9 - ENGINE/VALVE TIM-
ING/TIMING
BELT
/
CHAIN
COVER(S)
-
REMOVAL)
(16) Remove cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER
HEAD/CYLINDER
HEAD
COVER(S) - REMOVAL)
(17) Remove camshafts (Refer to 9 - ENGINE/
CYLINDER HEAD/CAMSHAFT(S) - REMOVAL).
NOTE: Identify rocker arm position to ensure cor-
rect re-installation in original position, if reused.
(18) Remove rocker arms. (Refer to 9 - ENGINE/
CYLINDER HEAD/ROCKER ARMS - REMOVAL).
(19) Remove cylinder head bolts in REVERSE
sequence of tightening.
(20) Remove cylinder head from engine block.
(21) Inspect and clean cylinder head. (Refer to 9 -
ENGINE/CYLINDER HEAD - INSPECTION) (Refer
to 9 - ENGINE/CYLINDER HEAD - CLEANING)
CLEANING
To ensure engine gasket sealing, proper surface
preparation must be performed, especially with the
use of aluminum engine components and multi-layer
steel cylinder head gaskets.
NOTE: Multi-Layer Steel (MLS) head gaskets require
a scratch free sealing surface.
Remove all gasket material from cylinder head and
block (Refer to 9 - ENGINE - STANDARD PROCE-
DURE). Be careful not to gouge or scratch the alumi-
num head sealing surface.
Clean all engine oil passages.
INSPECTION
(1)
Cylinder head must be flat within 0.1 mm
(0.004 in.) (Fig. 8).
(2)
Inspect camshaft bearing journals for scoring.
(3) Remove carbon and varnish deposits from
inside of valve guides with a reliable guide cleaner.
Fig. 8 Checking Cylinder Head Flatness
1 - FEELER GAUGE
2 - STRAIGHT EDGE
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ENGINE 2.4L
9 - 23
CYLINDER HEAD (Continued)
(4) Using a small hole gauge and a micrometer,
measure valve guides in 3 places top, middle and bot-
tom (Fig. 9). (Refer to 9 - ENGINE - SPECIFICA-
TIONS) Replace guides if they are not within
specification.
(5) Check valve guide height (Fig. 10).
INSTALLATION - CYLINDER HEAD
NOTE: The Cylinder head bolts should be examined
BEFORE reuse. If the threads are necked down, the
bolts must be replaced (Fig. 11).
Necking can be checked by holding a scale or
straight edge against the threads. If all the threads
do not contact the scale, the bolt should be replaced.
(1) Before installing the bolts, the threads should
be coated with engine oil.
(2) Position cylinder head gasket on engine block
(Fig. 12).
(3) Install cylinder head on engine block.
(4) Tighten the cylinder head bolts in the sequence
shown in (Fig. 13). Using the 4 step torque turn
method, tighten according to the following values:
• First All to 34 N·m (25 ft. lbs.)
• Second All to 68 N·m (50 ft. lbs.)
• Third All to 68 N·m (50 ft. lbs.)
CAUTION: Do not use a torque wrench for the fol-
lowing step.
• Fourth Turn an additional 1/4 Turn,
Fig. 9 Checking Wear on Valve Guide - Typical
1 - TOP
2 - MIDDLE
3 - BOTTOM
4 - CUT AWAY VIEW OF VALVE GUIDE MEASUREMENT
LOCATIONS
Fig. 10 Valve Guide Height
1 - VALVE GUIDE
2 - 13.25 - 13.75 MM (.521 - .541 IN.)
3 - SPRING SEAT
Fig. 11 Checking Bolts for Stretching (Necking)
1 - STRETCHED BOLT
2 - THREADS ARE NOT STRAIGHT ON LINE
3 - THREADS ARE STRAIGHT ON LINE
4 - UNSTRETCHED BOLT
Fig. 12 Cylinder Head Gasket Positioning
1 - PART NUMBER FACES UP
2 - NO. 1 CYLINDER
Fig. 13 Cylinder Head Tightening Sequence
9 - 24
ENGINE 2.4L
TJ
CYLINDER HEAD (Continued)
(5) Install rocker arms. (Refer to 9 - ENGINE/
CYLINDER HEAD/ROCKER ARMS - INSTALLA-
TION)
(6) Install camshafts. (Refer to 9 - ENGINE/CYL-
INDER HEAD/CAMSHAFT(S) - INSTALLATION).
(7) Install cylinder head cover. (Refer to 9 -
ENGINE/CYLINDER
HEAD/CYLINDER
HEAD
COVER(S) - INSTALLATION)
(8) Install timing belt rear cover and timing belt
idler pulley. (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT / CHAIN COVER(S) - INSTALLA-
TION)
(9)
Install timing belt and camshaft sprockets.
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT/CHAIN AND SPROCKETS - INSTALLATION)
(10) Connect cam sensor and fuel injectors wiring
connectors.
(11) Install ignition coil and wires. Connect igni-
tion coil wiring connector.
(12) Install accessary drive bracket.
(13) Install power steering pump to cylinder head.
(14) Raise vehicle and install the exhaust pipe to
the manifold.
(15) Install accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY
DRIVE/DRIVE
BELTS
-
INSTALLATION)
(16) Install heater tube support bracket to cylinder
head.
(17) Install intake manifold.
(18) Connect all vacuum lines, electrical wiring,
ground straps and fuel line.
(19) Fill cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(20) Connect battery negative cable.
CAMSHAFT OIL SEAL(S)
REMOVAL
(1) Remove timing belt. (Refer to 9 - ENGINE/
VALVE
TIMING/TIMING
BELT/CHAIN
AND
SPROCKETS - REMOVAL)
(2) Hold each camshaft sprocket with Special Tool
6847 while removing center bolt (Fig. 14).
(3) Remove camshaft sprockets.
(4) Remove exhaust camshaft target ring.
(5) Remove exhaust camshaft sensor.
CAUTION: Inspect sensor and target ring for exces-
sive wear. Clean sensor face and install new spacer
pad.
(6) Remove rear timing belt cover. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL)
(7) Remove
camshaft
seal
using
Special
Tool
C-4679-A (Fig. 15).
CAUTION: Do not nick shaft seal surface or seal
bore.
Fig. 14 Camshaft Sprocket - Removal/Installation
1 - SPECIAL TOOL 6847
Fig. 15 Camshaft Oil Seal - Removal With C-4679-A
1 - SPECIAL TOOL C-4679
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ENGINE 2.4L
9 - 25
CYLINDER HEAD (Continued)
INSTALLATION
NOTE: Clean and inspect sensor and target ring for
excessive wear. Clean sensor face and always
install a new spacer pad.
(1) Shaft seal surface must be free of varnish, dirt
or nicks. Polish with 400 grit paper if necessary.
(2) Install camshaft seals into cylinder head using
Special Tool MD-998306 until flush with head (Fig.
16).
(3) Install timing belt rear cover. (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION)
NOTE: Target ring tab should provide positive
snap-on fit on the camshaft.
(4) Install exhaust camshaft target ring with the
word FRONT facing forward.
(5) Install exhaust camshaft sensor.
(6) Install camshaft sprockets. Hold each sprocket
with Special Tool 6847 and tighten center bolt to 101
N·m (75 ft. lbs.).
(7) Install timing belt and front covers. (Refer to 9
- ENGINE/VALVE TIMING/TIMING BELT/CHAIN
AND SPROCKETS - INSTALLATION) (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION)
CAMSHAFT(S)
DESCRIPTION
Both nodular iron camshafts have six bearing jour-
nal surfaces and two cam lobes per cylinder (Fig. 17).
Flanges at the rear journals control camshaft end
play. Provision for a cam position sensor is located on
the exhaust camshaft on the front of the cylinder
head. A hydrodynamic oil seal is used for oil control
at the front of the camshaft.
OPERATION
The camshaft is driven by the crankshaft via drive
sprockets and belt. The camshaft has precisely
machined lobes to provide accurate valve timing and
duration.
Fig. 16 Camshaft Seal - Installation
1 - SPECIAL TOOL MD 998306
Fig. 17 Camshafts
1 - CAMSHAFT BEARING CAPS
2 - PLUG
3 - CAMSHAFT
4 - CYLINDER HEAD
5 - CAMSHAFT OIL SEAL
9 - 26
ENGINE 2.4L
TJ
CAMSHAFT OIL SEAL(S) (Continued)
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