1998 DODGE RAM 1500 Engine control 2

(12) Disconnect heater hoses from heater core and
remove hose assembly.
(13) Disconnect throttle and speed control cables.
(14) Remove upper radiator hose from engine.
(15) Remove lower radiator hose from engine.
(16) Remove radiator/cooling module assembly.
(17) Disconnect the engine to body ground straps
at the left side of cowl.
(18) Disconnect the engine wiring harness at the
following points:
²Intake air temperature (IAT) sensor
²Fuel Injectors
²Throttle Position (TPS) Switch
²Idle Air Control (IAC) Motor
²Engine Oil Pressure Switch
²Engine Coolant Temperature (ECT) Sensor
²Manifold Absolute Pressure MAP) Sensor
²Camshaft Position (CMP) Sensor
²Coil Over Plugs
²Crankshaft Position Sensor
(19) Remove coil over plugs.
(20) Release fuel rail pressure.
(21) Remove fuel rail and secure away from
engine.
NOTE: It is not necessary to release the quick con-
nect fitting from the fuel supply line for engine
removal.
(22) Remove the PCV hose.
(23) Remove the breather hoses.
(24) Remove the vacuum hose for the power brake
booster.
(25) Disconnect knock sensors.
(26) Remove engine oil dipstick tube.
(27) Remove intake manifold.
(28) Install engine lifting fixture,special tool#8247,
using original fasteners from the removed intake
manifold, and fuel rail. Torque to factory specifica-
tions.
NOTE: Recheck bolt torque for engine lift plate
before removing engine.
(29) Secure the left and right engine wiring har-
nesses away from engine.
(30) Raise vehicle.
(31) Disconnect oxygen sensor wiring.
(32) Disconnect crankshaft postion sensor.
(33) Disconnect the engine block heater power
cable, if equipped.
(34) Disconnect the front propshaft at the front
differential and secure out of way.
NOTE: It is necessary to disconnect the front prop-
shaft for access to the starter and left side exhaust
flange.(35) Remove the starter.
(36) Remove the ground straps from the left and
right side of the block.
(37) Disconnect the right and left exhaust pipes at
the manifolds and from the crossover, and remove
from the vehicle.
NOTE: The exhaust clamps at the manifolds cannot
be reused. New clamps must be used or leaks may
occur.
(38) Remove the structural cover.
(39) Remove torque convertor bolts, and mark
location for reassembly.
(40) Remove transmission bellhousing to engine
bolts.
(41) Remove left and right engine mount thru
bolts.
(42) Lower the vehicle.
(43) Support the transmission with a suitable jack.
(44) Connect a suitable engine hoist to the engine
lift plate.
(45) Remove engine from vehicle.
INSTALLATION
(1) Position the engine in the vehicle.
(2) Install both left and right side engine mounts
onto engine.
(3) Raise the vehicle.
(4) Install the transmission bellhousing to engine
mounting bolts. Tighten the bolts to 41 N´m (30ft.
lbs.).
(5) Tighten the engine mount thru bolts.
(6) Install the torque convertor bolts.
(7) Connect the ground straps on the left and right
side of the engine.
(8) Install the starter.
(9) Connect the crankshaft position sensor.
(10) Install the engine block heater power cable, if
equipped.
CAUTION: The structural cover requires a specific
torque sequence. Failure to follow this sequence
may cause severe damage to the cover.
(11) Install the structural cover.
NOTE: New clamps must be used on exhaust man-
ifold flanges. Failure to use new clamps may result
in exhaust leaks.
(12) Install the left and right exhaust pipes.
(13) Connect the left and right oxygen sensors.
(14) Lower vehicle.
(15) Remove the engine lift plate.
(16) Connect the knock sensors.
DRENGINE - 3.7L 9 - 11
ENGINE - 3.7L (Continued)

(17) Connect the engine to body ground straps at
the left side of the cowl.
(18) Install the intake manifold.
(19) Install the engine oil dipstick tube.
(20) Install the power brake booster vacuum hose.
(21) Install the breather hoses.
(22) Install the PCV hose.
(23) Install the fuel rail.
(24) Install the coil over plugs.
(25) Connect the engine wiring harness at the fol-
lowing points:
²Intake air temperature (IAT) sensor
²Fuel Injectors
²Throttle Position (TPS) Switch
²Idle Air Control (IAC) Motor
²Engine Oil Pressure Switch
²Engine Coolant Temperature (ECT) Sensor
²Manifold Absolute Pressure MAP) Sensor
²Camshaft Position (CMP) Sensor
²Coil Over Plugs
²Crankshaft Position Sensor
(26) Reinstall the radiator/cooling module assem-
bly.
(27) Connect lower radiator hose.
(28) Connect upper radiator hose.
(29) Connect throttle and speed control cables.
(30) Install the heater hose assembly.
(31) Install coolant recovery bottle.
(32) Install the power steering pump.
(33) Install the generator.
(34) Install the A/C compressor.
(35) Install the drive belt.
(36) Install the fan shroud with the viscous fan
assembly.
(37) Install the radiator core support bracket.
(38) Install the air cleaner assembly.
(39) Refill the engine cooling system.
(40) Recharge the air conditioning.
(41) Install the hood.
(42) Check and fill engine oil.
(43) Connect the battery negative cable.
(44) Start the engine and check for leaks.SPECIFICATIONS
SPECIFICATIONS - 3.7L ENGINE
GENERAL SPECIFICATIONS
DESCRIPTION SPECIFICATION
Type 90É SOHC V6 12 Valve
Number of
Cylinders4
Firing Order 1-6-5-4-3-2
Lead Cylinder No. 1 Left Bank
Compression
Ratio9.1:1
Max. Variation
Between
Cylinders25%
Metric Standard
Displacement 3.7 Liters 226 Cubic
Inches
Bore 93.0 mm 3.66 in.
Stroke 90.8 mm 3.40 in.
Horsepower 210@5200 RPM
Torque 225ft. lbs.@4200 PRM
Compression
Pressure1172-1551 kPa 170-225 psi
CYLINDER BLOCK
DESCRIPTION SPECIFICATION
Metric Standard
Bore Diameter 93.0   .0075
mm3.6619   0.0003
in.
Out of Round
(MAX)0.076 mm 0.003 in.
Taper (MAX) 0.051 mm 0.002 in.
9 - 12 ENGINE - 3.7LDR
ENGINE - 3.7L (Continued)

PISTONS
DESCRIPTION SPECIFICATION
Metric Standard
Diameter 92.975 mm 3.6605 in.
Weight 367.5 grams 12.96 oz
Ring Groove
Diameter
No. 1 83.73 - 83.13
mm3.296 - 3.273 in
No. 2 82.833 - 83.033
mm3.261 - 3.310 in.
No. 3 83.88 - 84.08
mm3.302 - 3.310 in.
PISTON PINS
DESCRIPTION SPECIFICATION
Metric Standard
Clearance In
Piston0.006 - 0.015
mm0.0002 - 0.0005
in.
Diameter 24.017 - 24.020
mm0.9455 - 0.9456
in.
PISTON RINGS
DESCRIPTION SPECIFICATION
Metric Standard
Ring Gap
To p
Compression
Ring0.20 - 0.36 mm 0.0079 - 0.0142
in.
Second
Compression
Ring0.37 - 0.63 mm 0.0146 - 0.0249
in.
Oil Control
(Steel Rails)0.25 - 0.76 mm 0.0099 - 0.30 in.
Side Clearance
To p
Compression
Ring.051 - .094 mm 0.0020 - 0.0037
in.
Second
Compression
Ring0.040 - 0.080
mm0.0016 - 0.0031
in.
Oil Ring (Steel
Ring).019 - .229 mm .0007 - .0091 in.
DESCRIPTION SPECIFICATION
Metric Standard
Ring Width
To p
Compression
Ring1.472 - 1.490
mm0.057 - 0.058 in.
Second
Compression
Ring1.472 - 1.490
mm0.057 - 0.058 in.
Oil Ring (Steel
Rails)0.445 - 0.470
mm0.017 - 0.018 in.
CONNECTING RODS
DESCRIPTION SPECIFICATION
Metric Standard
Bearing
Clearance0.015 - 0.055
mm0.0006 - 0.0022
in.
Side Clearance 0.10 - 0.35 mm 0.004 - 0.0138
in.
Piston Pin
Clearance.015 - .028 mm 0.0006 - 0.0011
in.
Bearing Bore
Out of Round
(MAX)0.004 mm 0.0002 in.
Total Weight
(Less Bearing)612 grams 21.588 ounces
DRENGINE - 3.7L 9 - 13
ENGINE - 3.7L (Continued)

²Step 1: Tighten bolts 1-8, 27 N´m (20 ft. lbs.).
²Step 2: Verify that bolts 1-8, all reached 27 N´m
(20 ft. lbs.), by repeating step 1 without loosening the
bolts. Tighten bolts 9 thru 12 to 14 N´m (10 ft. lbs.).
²Step 3: Tighten bolts 1-8, 90 degrees (Fig. 11).
²Step 4: Tighten bolts 1-8, 90 degrees, again.
Tighten bolts 9-12, 26 N´m (19 ft. lbs.)
(7) Position the secondary chain onto the camshaft
drive gear, making sure one marked chain link is on
either side of the V6 mark on the gear then using
Special Tool 8428 Camshaft Wrench, position the
gear onto the camshaft.
CAUTION: Remove excess oil from camshaft
sprocket retaining bolt before reinstalling bolt. Fail-
ure to do so may cause over-torqueing of bolt
resulting in bolt failure.
(8) Install the camshaft drive gear retaining bolt.
(9) Install the left side secondary chain guide(Re-
fer to 9 - ENGINE/VALVE TIMING/TIMING BELT/
CHAIN AND SPROCKETS - INSTALLATION).
(10) Install the cylinder head access plug.
(11) Re-set and install the left side secondary
chain tensioner(Refer to 9 - ENGINE/VALVE TIM-
ING/TIMING BELT/CHAIN AND SPROCKETS -
INSTALLATION).
(12) Remove Special Tool 8429.
(13) Install the timing chain cover(Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).(14) Install the crankshaft damper(Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION). Tighten damper bolt 175 N´m (130
Ft. Lbs.).
(15) Install the power steering pump.
(16) Install the fan blade assembly and fan shrou-
d(Refer to 7 - COOLING/ENGINE/RADIATOR FAN -
INSTALLATION).
(17) Install the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(18) Install the master cylinder and booster assem-
bly(Refer to 5 - BRAKES/HYDRAULIC/MECHANI-
CAL/POWER BRAKE BOOSTER - INSTALLATION).
(19) Install the intake manifold(Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION).
(20) Refill the cooling system(Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(21) Raise the vehicle.
(22) Install the exhaust pipe onto the left exhaust
manifold.
(23) Lower the vehicle.
(24) Connect the negative cable to the battery.
(25) Start the engine and check for leaks.
CAMSHAFT(S)
DESCRIPTION
The camshafts consist of powdered metal steel
lobes which are sinter-bonded to a steel tube. Four
bearing journals are machined into the camshaft.
Camshaft end play is controlled by two thrust walls
that border the nose piece journal. Engine oil enters
the hollow camshafts at the third journal and lubri-
cates every intake lobe rocker through a drilled pas-
sage in the intake lobe.
REMOVAL
CAUTION: When the timing chain is removed and
the cylinder heads are still installed, DO NOT force-
fully rotate the camshafts or crankshaft indepen-
dently of each other. Severe valve and/or piston
damage can occur.
CAUTION: When removing the cam sprocket, timing
chains or camshaft, Failure to use Special Tool
8379 will result in hydraulic tensioner ratchet over
extension, requiring timing chain cover removal to
reset the tensioner ratchet.
(1) Remove cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
Fig. 11 Cylinder head Tightening Sequence
* - INDICATES SEALANT ON THREADS
DRENGINE - 3.7L 9 - 25
CYLINDER HEAD - LEFT (Continued)

VALVE GUIDE SEALS
DESCRIPTION
The valve guide seals are made of rubber and
incorporate an integral steel valve spring seat. The
integral garter spring maintains consistent lubrica-
tion control to the valve stems.
VALVE SPRINGS
DESCRIPTION
The valve springs are made from high strength
chrome silicon steel. The springs are NOT common
for intake and exhaust applications. The exhaust
spring has an external damper. The valve spring seat
is integral with the valve stem seal, which is a posi-
tive type seal to control lubrication.
REMOVAL
(1) Remove the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(2) Using Special Tool 8516 Valve Spring Compres-
sor, remove the rocker arms and the hydraulic lash
adjusters.
(3) Remove the spark plug for the cylinder the
valve spring and seal are to be removed from.
(4) Apply shop air to the cylinder to hold the
valves in place when the spring is removed.
NOTE: All six valve springs and seals are removed
in the same manner; this procedure only covers
one valve seal and valve spring.
(5) Using Special Tool 8387 Valve Spring Compres-
sor, compress the valve spring.
NOTE: It may be necessary to tap the top of the
valve spring to loosen the spring retainers locks
enough to be removed.
(6) Remove the two spring retainer lock halves.
NOTE: the valve spring is under tension use care
when releasing the valve spring compressor.
(7) Remove the valve spring compressor.
NOTE: The valve springs are NOT common between
intake and exhaust.
(8) Remove the spring retainer, and the spring.
(9) Remove the valve stem seal.
NOTE: The valve stem seals are common between
intake and exhaust.
INSTALLATION
NOTE: All six valve springs and seals are removed
in the same manner; this procedure only covers
one valve seal and valve spring.
(1) Apply shop air to the cylinder to hold the
valves in place while the spring is installed.
NOTE: The valve stem seals are common between
intake and exhaust.
(2) Install the valve stem seal.
NOTE: The valve springs are NOT common between
intake and exhaust.
(3) Install the spring retainer, and the spring.
(4) Using Special Tool 8387 Valve Spring Compres-
sor, compress the valve spring.
(5) Install the two spring retainer lock halves.
NOTE: the valve spring is under tension use care
when releasing the valve spring compressor.
(6) Remove the valve spring compressor.
(7) Disconnect the shop air to the cylinder.
(8) Install the spark plug for the cylinder the valve
spring and seal was installed on.
(9) Using Special Tool 8516 Valve Spring Compres-
sor, install the rocker arms and the hydraulic lash
adjusters.
(10) Install the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
CYLINDER HEAD - RIGHT
DIAGNOSIS AND TESTING - HYDRAULIC LASH
ADJUSTER
A tappet-like noise may be produced from several
items. Check the following items.
(1) Engine oil level too high or too low. This may
cause aerated oil to enter the adjusters and cause
them to be spongy.
(2) Insufficient running time after rebuilding cylin-
der head. Low speed running up to 1 hour may be
required.
(3) Turn engine off and let set for a few minutes
before restarting. Repeat this several times after
engine has reached normal operating temperature.
(4) Low oil pressure.
(5) The oil restrictor in cylinder head gasket or the
oil passage to the cylinder head is plugged with
debris.
9 - 32 ENGINE - 3.7LDR

CAUTION: The nut on the right side camshaft
sprocket should not be removed for any reason, as
the sprocket and camshaft sensor target wheel is
serviced as an assembly. If the nut was removed,
torque nut to 5 NM ( 60 in. lbs.).
(7) Position the secondary chain onto the camshaft
drive gear, making sure one marked chain link is on
either side of the V6 mark on the gear then using
Special Tool 8428 Camshaft Wrench, position the
gear onto the camshaft.
CAUTION: Remove excess oil from camshaft
sprocket retaining bolt before reinstalling bolt. Fail-
ure to do so may cause over-torquing of bolt result-
ing in bolt failure.
(8) Install the camshaft drive gear retaining bolt.
(9) Install the right side secondary chain guide(Re-
fer to 9 - ENGINE/VALVE TIMING/TIMING BELT/
CHAIN AND SPROCKETS - INSTALLATION).
(10) Install the cylinder head access plug.
(11) Re-set and install the right side secondary
chain tensioner(Refer to 9 - ENGINE/VALVE TIM-
ING/TIMING BELT/CHAIN AND SPROCKETS -
INSTALLATION).
(12) Remove Special Tool 8429.
(13) Install the timing chain cover(Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL).
(14) Install the crankshaft damper(Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION). Tighten damper bolt 175 N´m (130
Ft. Lbs.).
(15) Install accessory drive belt(Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(16) Install the fan shroud(Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - INSTALLATION).
(17) Install the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(18) Install the intake manifold(Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION).
(19) Install oil fill housing onto cylinder head.
(20) Refill the cooling system(Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(21) Raise the vehicle.
(22) Install the exhaust pipe onto the right
exhaust manifold.
(23) Lower the vehicle.
(24) Reconnect battery negative cable.
(25) Start the engine and check for leaks.CAMSHAFT(S)
DESCRIPTION
The camshafts consist of powdered metal steel
lobes which are sinter-bonded to a steel tube. Four
bearing journals are machined into the camshaft.
Camshaft end play is controlled by two thrust walls
that border the nose piece journal. Engine oil enters
the hollow camshafts at the third journal and lubri-
cates every intake lobe rocker through a drilled pas-
sage in the intake lobe.
REMOVAL
CAUTION: When the timing chain is removed and
the cylinder heads are still installed, DO NOT force-
fully rotate the camshafts or crankshaft indepen-
dently of each other. Severe valve and/or piston
damage can occur.
CAUTION: When removing the cam sprocket, timing
chains or camshaft, Failure to use special tool 8379
will result in hydraulic tensioner ratchet over exten-
sion, Requiring timing chain cover removal to re-set
the tensioner ratchet.
(1) Remove the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(2) Set engine to TDC cylinder No. 1, camshaft
sprocket V6 marks at the 12 o'clock position.
(3) Mark one link on the secondary timing chain
on both sides of the V6 mark on the camshaft
sprocket to aid in installation.
CAUTION: Do not hold or pry on the camshaft tar-
get wheel for any reason, Severe damage will occur
to the target wheel. A damaged target wheel could
cause a vehicle no start condition.
(4) Loosen butDO NOTremove the camshaft
sprocket retaining bolt. Leave bolt snug against
sprocket.
NOTE: The timing chain tensioners must be
secured prior to removing the camshaft sprockets.
Failure to secure tensioners will allow the tension-
ers to extend, requiring timing chain cover removal
in order to reset tensioners.
CAUTION: Do not force wedge past the narrowest
point between the chain strands. Damage to the
tensioners may occur.
DRENGINE - 3.7L 9 - 35
CYLINDER HEAD - RIGHT (Continued)

VALVE GUIDE SEALS
DESCRIPTION
The valve guide seals are made of rubber and
incorporate an integral steel valve spring seat. The
integral garter spring maintains consistent lubrica-
tion control to the valve stems.
VALVE SPRINGS
DESCRIPTION
The valve springs are made from high strength
chrome silicon steel. There are different springs for
intake and exhaust applications. The exhaust spring
has an external damper. The valve spring seat is
integral with the valve stem seal, which is a positive
type seal to control lubrication.
REMOVAL
(1) Remove the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(2) Using Special Tool 8516 Valve Spring Compres-
sor, remove the rocker arms and the hydraulic lash
adjusters.
(3) Remove the spark plug for the cylinder the
valve spring and seal are to be removed from.
(4) Apply shop air to the cylinder to hold the
valves in place when the spring is removed.
NOTE: All six valve springs and seals are removed
in the same manner; this procedure only covers
one valve seal and valve spring.
(5) Using Special Tool 8387 Valve Spring Compres-
sor, compress the valve spring.
NOTE: It may be necessary to tap the top of the
valve spring to loosen the spring retainers locks
enough to be removed.
(6) Remove the two spring retainer lock halves.
NOTE: the valve spring is under tension use care
when releasing the valve spring compressor.
(7) Remove the valve spring compressor.
NOTE: The valve springs are NOT common between
intake and exhaust.
(8) Remove the spring retainer, and the spring.
(9) Remove the valve stem seal.
NOTE: The valve stem seals are common between
intake and exhaust.
INSTALLATION
NOTE: All six valve springs and seals are removed
in the same manner; this procedure only covers
one valve seal and valve spring.
(1) Apply shop air to the cylinder to hold the
valves in place while the spring is installed.
NOTE: The valve stem seals are common between
intake and exhaust.
(2) Install the valve stem seal.
NOTE: The valve springs are NOT common between
intake and exhaust.
(3) Install the spring retainer, and the spring.
(4) Using Special Tool 8387 Valve Spring Compres-
sor, compress the valve spring.
(5) Install the two spring retainer lock halves.
NOTE: the valve spring is under tension use care
when releasing the valve spring compressor.
(6) Remove the valve spring compressor.
(7) Disconnect the shop air to the cylinder.
(8) Install the spark plug for the cylinder the valve
spring and seal was installed on.
(9) Using Special Tool 8516 Valve Spring Compres-
sor, install the rocker arms and the hydraulic lash
adjusters.
(10) Install the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
ENGINE BLOCK
DESCRIPTION
The cylinder block is made of cast iron. The block
is a closed deck design with the left bank forward. To
provide high rigidity and improved NVH an
enhanced compacted graphite bedplate is bolted to
the block. The block design allows coolant flow
between the cylinders bores, and an internal coolant
bypass to a single poppet inlet thermostat is included
in the cast aluminum front cover.
STANDARD PROCEDURE - CYLINDER BORE
HONING
Before honing, stuff plenty of clean shop towels
under the bores and over the crankshaft to keep
abrasive materials from entering the crankshaft
area.
(1) Used carefully, the Cylinder Bore Sizing Hone
C-823, equipped with 220 grit stones, is the best tool
9 - 38 ENGINE - 3.7LDR

for this job. In addition to deglazing, it will reduce
taper and out-of-round, as well as removing light
scuffing, scoring and scratches. Usually, a few strokes
will clean up a bore and maintain the required lim-
its.
CAUTION: DO NOT use rigid type hones to remove
cylinder wall glaze.
(2) Deglazing of the cylinder walls may be done if
the cylinder bore is straight and round. Use a cylin-
der surfacing hone, Honing Tool C-3501, equipped
with 280 grit stones (C-3501-3810). about 20-60
strokes, depending on the bore condition, will be suf-
ficient to provide a satisfactory surface. Using honing
oil C-3501-3880, or a light honing oil, available from
major oil distributors.
CAUTION: DO NOT use engine or transmission oil,
mineral spirits, or kerosene.
(3) Honing should be done by moving the hone up
and down fast enough to get a crosshatch pattern.
The hone marks should INTERSECT at 50É to 60É
for proper seating of rings (Fig. 29).
(4) A controlled hone motor speed between 200 and
300 RPM is necessary to obtain the proper cross-
hatch angle. The number of up and down strokes per
minute can be regulated to get the desired 50É to 60É
angle. Faster up and down strokes increase the cross-
hatch angle.(5) After honing, it is necessary that the block be
cleaned to remove all traces of abrasive. Use a brush
to wash parts with a solution of hot water and deter-
gent. Dry parts thoroughly. Use a clean, white, lint-
free cloth to check that the bore is clean. Oil the
bores after cleaning to prevent rusting.
CLEANING
Thoroughly clean the oil pan and engine block gas-
ket surfaces.
Use compressed air to clean out:
²The galley at the oil filter adaptor hole.
²The front and rear oil galley holes.
²The feed holes for the crankshaft main bearings.
Once the block has been completely cleaned, apply
Loctite PST pipe sealant with Teflon 592 to the
threads of the front and rear oil galley plugs. Tighten
the 1/4 inch NPT plugs to 20 N´m (177 in. lbs.)
torque. Tighten the 3/8 inch NPT plugs to 27 N´m
(240 in. lbs.) torque.
INSPECTION
(1) It is mandatory to use a dial bore gauge to
measure each cylinder bore diameter. To correctly
select the proper size piston, a cylinder bore gauge,
capable of reading in 0.003 mm (.0001 in.) INCRE-
MENTS is required. If a bore gauge is not available,
do not use an inside micrometer (Fig. 30).
Fig. 29 CYLINDER BORE CROSSHATCH PATTERN
1 - CROSSHATCH PATTERN
2 - INTERSECT ANGLE
Fig. 30 BORE GAUGE-TYPICAL
1 - FRONT
2 - BORE GAUGE
3 - CYLINDER BORE
4 - 38 MM (1.5 in)
DRENGINE - 3.7L 9 - 39
ENGINE BLOCK (Continued)