Chrysler Town, Dodge Caravan. Manual — part 303
INSPECTION
(1) Inspect camshaft bearing journals for damage
and binding (Fig. 27). If journals are binding, check
the cylinder head for damage. Also check cylinder
head oil holes for clogging.
(2) Check the cam lobe and bearing surfaces for
abnormal wear and damage. Replace camshaft if
defective.
NOTE: If camshaft is replaced due to lobe wear or
damage, always replace the rocker arms.
(3) Measure the lobe actual wear (unworn area -
wear zone = actual wear) (Fig. 27) and replace cam-
shaft if out of limit. Standard value is 0.0254 mm
(0.001 in.), wear limit is 0.254 mm (0.010 in.).
INSTALLATION
CAUTION: Ensure that NONE of the pistons are at
top dead center when installing the camshafts.
(1) Lubricate all camshaft bearing journals, rocker
arms and camshaft lobes.
(2) Install all rocker arms in original positions, if
reused.
(3) Position camshafts on cylinder head bearing
journals. Install right and left camshaft bearing caps
No. 2 – 5 and right No. 6. Tighten M6 fasteners to 12
N·m (105 in. lbs.) in sequence shown in (Fig. 28).
(4) Apply Mopar
t Gasket Maker to No. 1 and No.
6 bearing caps (Fig. 29). Install bearing caps and
tighten M8 fasteners to 28 N·m (250 in. lbs.).
NOTE: Bearing end caps must be installed before
seals can be installed.
(5) Install
camshaft
oil
seals
(Refer
to
9
-
ENGINE/CYLINDER
HEAD/CAMSHAFT
OIL
SEAL(S) - INSTALLATION).
(6) Install camshaft target magnet and camshaft
position sensor.
Fig. 26 Camshaft Bearing Cap - Removal
1 - REMOVE OUTSIDE BEARING CAPS FIRST
Fig. 27 Checking Camshaft(s) for Wear
1 - UNWORN AREA
2 - ACTUAL WEAR
3 - BEARING JOURNAL
4 - LOBE
5 - WEAR ZONE
Fig. 28 Camshaft Bearing Cap Tightening Sequence
Fig. 29 Camshaft Bearing Cap Sealing
1 - 1.5 mm (.060 in.) DIAMETER BEAD OF MOPAR GASKET
MAKER
9 - 30
ENGINE 2.4L
RS
CAMSHAFT(S) (Continued)
(7) Install cylinder head cover (Refer to 9 -
ENGINE/CYLINDER
HEAD/CYLINDER
HEAD
COVER - INSTALLATION).
(8) Install timing belt rear cover and camshaft
sprockets (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT COVER(S) - INSTALLATION).
(9) Install timing belt (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT AND SPROCKETS -
INSTALLATION).
CYLINDER HEAD COVER
REMOVAL
(1) Remove upper intake manifold. (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE
MANIFOLD
-
REMOVAL)
(2) Remove upper manifold support bracket.
(3) Remove ignition coil and spark plug wires.
(4) Disconnect PCV and make-up air hoses from
cylinder head cover.
(5) Remove cylinder head cover bolts.
(6) Remove cylinder head cover from cylinder
head.
CLEANING
Clean cylinder head and cover mating surfaces
using a suitable solvent.
INSPECTION
Inspect cover rails for flatness.
INSTALLATION
NOTE: Replace spark plug well seals and bolt
assemblies when installing a new cylinder head
cover gasket.
(1) Install new cylinder head cover gaskets and
spark plug well seals (Fig. 30).
(2) Replace cylinder head cover bolt assemblies.
CAUTION: Do not allow oil or solvents to contact
the timing belt as they can deteriorate the rubber
and cause tooth skipping.
(3)
Apply Mopar
t Engine RTV GEN II at the
camshaft cap corners and at the top edges of the 1/2
round seal (Fig. 31).
(4)
Install cylinder head cover assembly to cylin-
der head. Install all bolts, ensuring the single (1)
stud used to attach the upper intake manifold sup-
port bracket is located in the #8 location as shown in
torque sequence diagram (Fig. 32). Tighten bolts in
sequence shown in (Fig. 32). Using a 3 step torque
method as follows:
(a) Tighten all bolts to 4.5 N·m (40 in. lbs.).
(b) Tighten all bolts to 9.0 N·m (80 in. lbs.).
(c) Tighten all bolts to 12 N·m (105 in. lbs.).
(5) Install ignition coil and spark plug wires.
Tighten fasteners to 12 N·m (105 in. lbs.).
Fig. 30 Spark Plug Well Seals
Fig. 31 Sealer Locations
1 – SEALER LOCATION
RS
ENGINE 2.4L
9 - 31
CAMSHAFT(S) (Continued)
(6) If the PCV valve was removed, apply Mopar
t
Thread Sealant with Teflon to threads and install
valve to cylinder head cover. Tighten PCV valve to 8
N·m (70 in. lbs.).
(7) Connect PCV and make-up air hoses to cylin-
der head cover.
(8) Install upper intake manifold. (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE
MANIFOLD
-
INSTALLATION)
INTAKE/EXHAUST VALVES &
SEATS
DESCRIPTION
The valves are made of heat resistant steel. They
have chrome plated stems to prevent scuffing. Viton
rubber valve stem seals are integral with the spring
seats. The valves have three-bead lock keepers to
retain springs and to promote valve rotation.
CLEANING
(1) Clean
all
valves
thoroughly
and
discard
burned, warped and cracked valves.
VALVE SPRINGS & SEALS
REMOVAL
REMOVAL - CYLINDER HEAD ON
(1) Remove cylinder head cover (Refer to 9 -
ENGINE/CYLINDER
HEAD/CYLINDER
HEAD
COVER(S) - REMOVAL).
(2) Remove camshafts (Refer to 9 - ENGINE/CYL-
INDER HEAD/CAMSHAFT(S) - REMOVAL).
(3) Rotate crankshaft until piston is at TDC on
compression.
(4) With air hose attached to adapter tool installed
in spark plug hole, apply 90-120 psi air pressure.
(5) Using Special Tool MD-998772-A with adapter
6779 (Fig. 33), compress valve springs and remove
valve locks.
(6) Remove valve spring(s).
(7) Remove valve stem seal(s) by a using valve
stem seal tool (Fig. 35).
REMOVAL - CYLINDER HEAD OFF
(1) With cylinder head removed from cylinder
block, compress valve springs using a universal valve
spring compressor.
(2) Remove valve retaining locks, valve spring
retainers, valve stem seals and valve springs.
(3) Before removing valves, remove any burrs
from valve stem lock grooves to prevent dam-
age to the valve guides. Identify valves, locks and
retainers to insure installation in original location.
(4) Inspect the valves. (Refer to 9 - ENGINE/CYL-
INDER HEAD/VALVE SPRINGS - INSPECTION)
INSPECTION
(1) Whenever valves have been removed for inspec-
tion, reconditioning or replacement, valve springs
should be tested for correct tension. Discard the
springs that do not meet specifications. The following
specifications apply to both intake and exhaust
valves springs:
• Valve Closed Nominal Tension—76 lbs. @ 38.0
mm (1.50 in.)
• Valve Open Nominal Tension—136 lbs. @ 29.75
mm (1.17 in.)
(2) Inspect each valve spring for squareness with a
steel square and surface plate, test springs from both
ends. If the spring is more than 1.5 mm (1/16 inch)
out of square, install a new spring.
Fig. 32 Cylinder Head Cover Tightening Sequence
(Typical Cover Shown)
Fig. 33 Valve Spring - Removal/Installation
1 - VALVE SPRING COMPRESSOR MD 998772A
2 - AIR HOSE
9 - 32
ENGINE 2.4L
RS
CYLINDER HEAD COVER (Continued)
INSTALLATION
INSTALLATION - CYLINDER HEAD ON
(1)
Install valve seal/valve spring seat assembly
(Fig. 34). Push the assembly down to seat it onto the
valve guide.
(2)
Install valve spring and retainer, use Special
Tool MD-998772-A with adapter 6779 to compress
valve springs only enough to install locks (Fig. 33).
Correct alignment of tool is necessary to avoid nick-
ing valve stems.
(3)
Remove air hose and install spark plugs.
(4)
Install camshafts (Refer to 9 - ENGINE/CYL-
INDER HEAD/CAMSHAFT(S) - INSTALLATION).
(5) Install cylinder head cover (Refer to 9 -
ENGINE/CYLINDER
HEAD/CYLINDER
HEAD
COVER - INSTALLATION).
INSTALLATION - CYLINDER HEAD OFF
(1)
Coat valve stems with clean engine oil and
insert in cylinder head.
(2)
Install new valve stem seals on all valves
using a valve stem seal tool (Fig. 35). The valve stem
seals should be pushed firmly and squarely over
valve guide.
CAUTION: When oversize valves are used, the cor-
responding oversize valve seal must also be used.
Excessive guide wear may result if oversize seals
are not used with oversize valves.
(3)
Install valve springs and retainers. Compress
valve springs only enough to install locks, taking
care not to misalign the direction of compression.
Nicked valve stems may result from misalignment of
the valve spring compressor.
CAUTION: When depressing the valve spring retain-
ers with valve spring compressor the locks can
become dislocated. Ensure both locks are in the
correct location after removing tool.
(4) Check the valve spring installed height B after
refacing the valve and seat (Fig. 36). Make sure mea-
surements are taken from top of spring seat to the
bottom surface of spring retainer. If height is greater
than 38.75 mm (1.525 in.), install a 0.762 mm (0.030
in.) spacer under the valve spring seat to bring
spring height back within specification.
Fig. 34 Valve Stem Seal/Valve Spring Seat
1 - VALVE RETAINING LOCKS
2 - VALVE SPRING
3 - VALVE SEAL AND VALVE SPRING SEAT ASSEMBLY
4 - VALVE SPRING RETAINER
Fig. 35 Valve Stem Oil Seal Tool
1 - VALVE SEAL TOOL
2 - VALVE STEM
Fig. 36 Checking Spring Installed Height and Valve
Tip Height Dimensions
1 - GARTER SPRING
2 - VALVE SPRING SEAT
3 - CYLINDER HEAD SURFACE
RS
ENGINE 2.4L
9 - 33
VALVE SPRINGS & SEALS (Continued)
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