2001 DODGE RAM length

DESCRIPTION SPECIFICATION
Number of Coils 6.8
Installed Height 41.66 mm
(1.64 in.)
Wire Diameter 4.50 mm
(0.177 in.)
HYDRAULIC TAPPETS
Body Diameter 22.949 - 22.962 mm
(0.9035 - 0.9040 in.)
Clearance in Block 0.0279 - 0.0610 mm
(0.0011 - 0.210 in.)
Dry Lash 1.524 - 5.334 mm
(0.060 - 0.210 in.)
Push Rod Length 175.64 - 176.15 mm
(6.915 - 6.935 in.)
OIL PRESSURE
@ Curb Idle (Min.)* 41.4 kPa
(6 psi)
@ 3000 rpm 207 - 552 kPa
(30 - 80 psi)
Bypass Valve Setting 62 - 103 kPa
(9 - 15 psi)
Switch Actuating
Pressure34.5 - 48.3 kPa
(5 - 7 psi)
* If oil pressure is zero at curb idle, DO NOT RUN
ENGINE.
OIL PUMP
Clearance Over Rotors
(Max) 0.1016 mm
(0.004 in.)
Cover Out of Flat
(Max) 0.0381 mm
(0.0015 in.)
Inner Rotor Thickness
(Min) 20.955 mm
(0.825 in.)DESCRIPTION SPECIFICATION
Outer Rotor Clearance
(Max) 0.3556 mm
(0.014 in.)
Outer Rotor Diameter
(Min) 62.7126 mm
(2.469 in.)
Outer Rotor Thickness
(Min) 20.955 mm
(0.825 in.)
Tip Clearance Between
Rotors
(Max) 0.2032 mm
(0.008 in.)
PISTONS
Clearance at Top of Skirt 0.0127 - 0.0381 mm
(0.0005 - 0.0015 in.)
Land Clearance
(Diameter)0.635 - 1.016 mm
(0.025 - 0.040 in.)
Piston Length 86.360 mm
(3.40 in.)
Ring Groove Depth
#1 & 2 4.572 - 4.826 mm
(0.180 - 0.190 in.)
#3 3.810 - 4.064 mm
(0.150 - 0.160 in.)
Weight 592.6 - 596.6 grams
(20.90 - 21.04 oz.)
PISTON PINS
Clearance in Piston 0.0064 - 0.0191 mm
(0.00025 - 0.00075 in.)
Clearance in Rod
(Interference)0.0178 - 0.0356 mm
(0.0007 - 0.0014 in.)
Diameter 24.996 - 25.001 mm
(0.9841 - 0.9843 in.)
9 - 16 ENGINE 3.9LBR/BE
ENGINE 3.9L (Continued)

DESCRIPTION SPECIFICATION
End Play None
Length 75.946 - 76.454 mm
(2.990 - 3.010 in.)
PISTON RINGS
Ring Gap
Compression Rings 0.254 - 0.508 mm
(0.010 - 0.020 in.)
Oil Control (Steel Rails) 0.254 - 1.270 mm
(0.010 - 0.050 in.)
Ring Side Clearance
Compression Rings 0.038 - 0.076 mm
(0.0015 - 0.0030 in.)
Oil Control (Steel Rails) 0.06 - 0.21 mm
(0.002 - 0.008 in.)
Ring Width
Compression Rings 1.971 - 1.989 mm
(0.0776 - 0.0783 in.)
Oil Control (Steel Rails) 3.848 - 3.975 mm
(0.1515 - 0.1565 in.)
VALVE TIMING
Exhaust Valve
Closes 16É (ATDC)
Opens 52É (BBDC)
Duration 248É
Intake Valve
Closes 50É (ABDC)
Opens 10É (BTDC)
Duration 240É
Valve Overlap 26ÉOVERSIZE AND UNDERSIZE ENGINE
COMPONENT MARKINGS CHART
OS-US Item Identification Location of
Identification
U/S Crankshaft R or M M-2-3
ect.Milled flat on
.0254
MM(indicating No.
2&No. eight
(.001
IN.)3 main
bearingcrankshaft
journal) and/or counterweight.
R-1-4 ect.
(indicating No.
1&
4 connecting
rod
journal)
O/S TappetsL3/89
.2032
mmdiamound
(.008 in.) -shaped
stamp Top
pad
Ð Front of
engine and
flat
ground on
outside
surface
of each O/S
tappet bore.
O/S Valve
StemsX Milled pad
.127 mm adjacent to
two
(0.005
in.)3/89tapped
holes on
each
end of
cylinder
head.
BR/BEENGINE 3.9L 9 - 17
ENGINE 3.9L (Continued)

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
The alloy cast iron cylinder heads (Fig. 7) are held
in place by eight bolts. The spark plugs are located
at the peak of the wedge between the valves.
(1) Disconnect the battery negative cable from the
battery.
(2) Drain cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Remove the intake manifold-to-generator
bracket support rod. Remove the generator.
(4) Remove closed crankcase ventilation system.
(5) Disconnect the evaporation control system.
(6) Remove the air cleaner, air in-let hose and res-
onator.
(7) Perform fuel system pressure release procedure
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
(8) Disconnect the fuel supply line from the fuel
rail (Refer to 14 - FUEL SYSTEM/FUEL DELIVERY/
QUICK CONNECT FITTING - STANDARD PROCE-
DURE).
(9) Disconnect accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.
(10) Remove distributor cap and wires.
(11) Disconnect the coil wires.
(12) Disconnect coolant temperature sending unit
wire.
(13) Disconnect heater hoses and bypass hose.
(14) Disconnect the vacuum supply hoses from the
intake manifold.
(15) Disconnect the fuel injector harness and
secure out of the way.
(16) Remove cylinder head covers and gaskets
(Refer to 9 - ENGINE/CYLINDER HEAD/CYLIN-
DER HEAD COVER(S) - REMOVAL).(17) Remove intake manifold and throttle body as
an assembly. Discard the flange side gaskets and the
front and rear cross-over gaskets.
(18) Remove exhaust manifolds (Refer to 9 -
ENGINE/MANIFOLDS/EXHAUST MANIFOLD -
REMOVAL).
(19) Remove rocker arm assemblies and push rods.
Identify to ensure installation in original locations.
(20) Remove the head bolts from each cylinder
head and remove cylinder heads. Discard the cylin-
der head gasket.
(21) Remove spark plugs.
CLEANING
Clean all surfaces of cylinder block and cylinder
heads.
Clean cylinder block front and rear gasket surfaces
using a suitable solvent.
INSPECTION
Inspect all surfaces with a straightedge if there is
any reason to suspect leakage. If out-of-flatness
exceeds 0.00075mm (0.0001in.) times the span length
in any direction, either replace head or lightly
machine the head surface.
FOR EXAMPLE:ÐA 305 mm (12 in.) span is
0.102 mm (0.004 in.) out-of-flat. The allowable out-of-
flat is 305 x 0.00075 (12 x 0.00075) equals 0.23 mm
(0.009 in.). This amount of out-of-flat is acceptable.
The cylinder head surface finish should be
1.78-3.00 microns (70-125 microinches).
Inspect push rods. Replace worn or bent rods.
INSTALLATION
The alloy cast iron cylinder heads (Fig. 7) are held
in place by eight bolts. The spark plugs are located
at the peak of the wedge between the valves.
(1) Position the new cylinder head gaskets onto
the cylinder block.
(2) Position the cylinder heads onto head gaskets
and cylinder block.
(3) Starting at top center, tighten all cylinder head
bolts, in sequence, to 68 N´m (50 ft. lbs.) torque (Fig.
7). Repeat procedure, tighten all cylinder head bolts
to 143 N´m (105 ft. lbs.) torque. Repeat procedure to
confirm that all bolts are at 143 N´m (105 ft. lbs.)
torque.
CAUTION: When tightening the rocker arm bolts, be
sure the piston in that cylinder is NOT at TDC. Con-
tact between the valves and piston could occur.
(4) Install push rods and rocker arm assemblies in
their original positions. Tighten the bolts to 28 N´m
(21 ft. lbs.) torque.
BR/BEENGINE 3.9L 9 - 23
CYLINDER HEAD (Continued)

(1) When refacing valve seats, it is important that
the correct size valve guide pilot be used for reseat-
ing stones. A true and complete surface must be
obtained.
(2) Measure the concentricity of valve seat using a
dial indicator. Total runout should not exceed 0.051
mm (0.002 in.) total indicator reading.
(3) Inspect the valve seat with Prussian blue, to
determine where the valve contacts the seat. To do
this, coat valve seat LIGHTLY with Prussian blue
then set valve in place. Rotate the valve with light
pressure. If the blue is transferred to the center of
valve face, contact is satisfactory. If the blue is trans-
ferred to the top edge of valve face, lower valve seat
with a 15É stone. If the blue is transferred to bottom
edge of valve face raise valve seat with a 60É stone.
(4) When seat is properly positioned the width of
intake seats should be 1.016-1.524 mm (0.040-0.060
in.). The width of the exhaust seats should be 1.524-
2.032 mm (0.060-0.080 in.).
VALVE SPRINGS
Whenever valves have been removed for inspection,
reconditioning or replacement, valve springs should
be tested. As an example the compression length of
the spring to be tested is 1-5/16 in.. Turn table of
Universal Valve Spring Tester Tool until surface is in
line with the 1-5/16 in. mark on the threaded stud.
Be sure the zero mark is to the front (Fig. 14). Place
spring over stud on the table and lift compressing
lever to set tone device. Pull on torque wrench until
ping is heard. Take reading on torque wrench at this
instant. Multiply this reading by 2. This will give the
spring load at test length. Fractional measurements
are indicated on the table for finer adjustments.
Refer to specifications to obtain specified height and
allowable tensions. Discard the springs that do not
meet specifications.
REMOVAL
(1) Remove the cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - REMOVAL).
(2) Compress valve springs using Valve Spring
Compressor Tool MD- 998772A and adapter 6716A.
(3) Remove valve retaining locks, valve spring
retainers, valve stem seals and valve springs.
(4) Before removing valves, remove any burrs from
valve stem lock grooves to prevent damage to the
valve guides. Identify valves to ensure installation in
original location.
CLEANING
Clean valves thoroughly. Discard burned, warped,
or cracked valves.
Remove carbon and varnish deposits from inside of
valve guides with a reliable guide cleaner.
INSPECTION
Measure valve stems for wear. If wear exceeds
0.051 mm (0.002 in.), replace the valve.
Measure valve stem guide clearance as follows:
(1) Install Valve Guide Sleeve Tool C-3973 over
valve stem and install valve (Fig. 15). The special
sleeve places the valve at the correct height for
checking with a dial indicator.
(2) Attach dial indicator Tool C-3339 to cylinder
head and set it at right angles to valve stem being
measured (Fig. 16).
(3) Move valve to and from the indicator. The total
dial indicator reading should not exceed 0.432 mm
(0.017 in.). Ream the guides for valves with oversize
stems if dial indicator reading is excessive or if the
stems are scuffed or scored.
Fig. 14 Testing Valve Spring for Compressed
Length
1 - TORQUE WRENCH
2 - VALVE SPRING TESTER
Fig. 15 Positioning Valve with Tool C-3973
1 - VALVE
2 - SPACER TOOL
BR/BEENGINE 3.9L 9 - 27
INTAKE/EXHAUST VALVES & SEATS (Continued)

HYDRAULIC LIFTERS (CAM IN
BLOCK)
DIAGNOSIS AND TESTINGÐHYDRAULIC
TAPPETS
Before disassembling any part of the engine to cor-
rect tappet noise, check the oil pressure. If vehicle
has no oil pressure gauge, install a reliable gauge at
the pressure sending-unit. The pressure should be
between 207-552 kPa (30-80 psi) at 3,000 RPM.
Check the oil level after the engine reaches normal
operating temperature. Allow 5 minutes to stabilize
oil level, check dipstick. The oil level in the pan
should never be above the FULL mark or below the
ADD OIL mark on dipstick. Either of these two con-
ditions could be responsible for noisy tappets.
OIL LEVEL
HIGH
If oil level is above the FULL mark, it is possible
for the connecting rods to dip into the oil. With the
engine running, this condition could create foam in
the oil pan. Foam in oil pan would be fed to the
hydraulic tappets by the oil pump causing them to
lose length and allow valves to seat noisily.
LOW
Low oil level may allow oil pump to take in air.
When air is fed to the tappets, they lose length,
which allows valves to seat noisily. Any leaks on
intake side of oil pump through which air can be
drawn will create the same tappet action. Check the
lubrication system from the intake strainer to the
pump cover, including the relief valve retainer cap.
When tappet noise is due to aeration, it may be
intermittent or constant, and usually more than one
tappet will be noisy. When oil level and leaks have
been corrected, operate the engine at fast idle. Run
engine for a sufficient time to allow all of the air
inside the tappets to be bled out.
TAPPET NOISE DIAGNOSIS
(1) To determine source of tappet noise, operate
engine at idle with cylinder head covers removed.
(2) Feel each valve spring or rocker arm to detect
noisy tappet. The noisy tappet will cause the affected
spring and/or rocker arm to vibrate or feel rough in
operation.
NOTE: Worn valve guides or cocked springs are
sometimes mistaken for noisy tappets. If such is
the case, noise may be dampened by applying side
thrust on the valve spring. If noise is not apprecia-
bly reduced, it can be assumed the noise is in thetappet. Inspect the rocker arm push rod sockets
and push rod ends for wear.
(3) Valve tappet noise ranges from light noise to a
heavy click. A light noise is usually caused by exces-
sive leak-down around the unit plunger, or by the
plunger partially sticking in the tappet body cylinder.
The tappet should be replaced. A heavy click is
caused by a tappet check valve not seating, or by for-
eign particles wedged between the plunger and the
tappet body. This will cause the plunger to stick in
the down position. This heavy click will be accompa-
nied by excessive clearance between the valve stem
and rocker arm as valve closes. In either case, tappet
assembly should be removed for inspection and clean-
ing.
(4) The valve train generates a noise very much
like a light tappet noise during normal operation.
Care must be taken to ensure that tappets are mak-
ing the noise. If more than one tappet seems to be
noisy, it's probably not the tappets.
LEAK-DOWN TEST
After cleaning and inspection, test each tappet for
specified leak-down rate tolerance to ensure zero-lash
operation (Fig. 38).
Swing the weighted arm of the hydraulic valve tap-
pet tester away from the ram of the Universal Leak-
Down Tester.
(1) Place a 7.925-7.950 mm (0.312-0.313 inch)
diameter ball bearing on the plunger cap of the tap-
pet.
(2) Lift the ram and position the tappet (with the
ball bearing) inside the tester cup.
(3) Lower the ram, then adjust the nose of the ram
until it contacts the ball bearing. DO NOT tighten
the hex nut on the ram.
(4) Fill the tester cup with hydraulic valve tappet
test oil until the tappet is completely submerged.
(5) Swing the weighted arm onto the push rod and
pump the tappet plunger up and down to remove air.
When the air bubbles cease, swing the weighted arm
away and allow the plunger to rise to the normal
position.
(6) Adjust the nose of the ram to align the pointer
with the SET mark on the scale of the tester and
tighten the hex nut.
(7) Slowly swing the weighted arm onto the push
rod.
(8) Rotate the cup by turning the handle at the
base of the tester clockwise one revolution every 2
seconds.
(9) Observe the leak-down time interval from the
instant the pointer aligns with the START mark on
the scale until the pointer aligns with the 0.125
mark. A normally functioning tappet will require
9 - 38 ENGINE 3.9LBR/BE

(3) Using the transmission jack, lower the trans-
mission and support cushion onto the crossmember
(Fig. 49).
(4) Install the support cushion bolts and tighten to
41 N´m (30 ft. lbs.) torque.
(5) Remove the transmission jack.
(6) Lower the vehicle.
LUBRICATION
DESCRIPTION
A gear-type positive displacement pump (Fig. 50)is
mounted at the underside of the rear main bearing
cap. The pump uses a pick-up tube and screen
assembly to gather engine oil from the oil pan.
OPERATION
The pump draws oil through the screen and inlet
tube from the sump at the rear of the oil pan. The oil
is driven between the drive and idler gears and
pump body, then forced through the outlet to the
block. An oil gallery in the block channels the oil to
the inlet side of the full flow oil filter. After passing
through the filter element, the oil passes from the
center outlet of the filter through an oil gallery that
channels the oil up to the main gallery, which
extends the entire length on the right side of the
block. The oil then goes down to the No. 1 main bear-
ing, back up to the left side of the block, and into the
oil gallery on the left side of the engine.
Galleries extend downward from the main oil gal-
lery to the upper shell of each main bearing. The
crankshaft is drilled internally to pass oil from the
main bearing journals to the connecting rod journals.
Each connecting rod bearing has half a hole in it, oil
passes through the hole when the rods rotate and the
hole lines up, oil is then thrown off as the rod
rotates. This oil throwoff lubricates the camshaft
lobes, distributor drive gear, cylinder walls, and pis-
ton pins.The hydraulic valve tappets receive oil directly
from the main oil gallery. The camshaft bearings
receive oil from the main bearing galleries. The front
camshaft bearing journal passes oil through the cam-
shaft sprocket to the timing chain. Oil drains back to
the oil pan under the No. 1 main bearing cap.
The oil supply for the rocker arms and bridged
pivot assemblies is provided by the hydraulic valve
tappets, which pass oil through hollow push rods to a
hole in the corresponding rocker arm. Oil from the
rocker arm lubricates the valve train components.
The oil then passes down through the push rod guide
holes and the oil drain-back passages in the cylinder
head, past the valve tappet area, and then returns to
the oil pan (Fig. 51).
Fig. 50 Positive Displacement Oil PumpÐTypical
1 - INNER ROTOR AND SHAFT
2 - BODY
3 - DISTRIBUTOR DRIVESHAFT (REFERENCE)
4 - COTTER PIN
5 - RETAINER CAP
6 - SPRING
7 - RELIEF VALVE
8 - LARGE CHAMFERED EDGE
9 - BOLT
10 - COVER
11 - OUTER ROTOR
BR/BEENGINE 3.9L 9 - 45
REAR MOUNT (Continued)

Measure thickness and diameter of outer rotor. If
outer rotor thickness measures 20.9 mm (0.825 in.)
or less, or if the diameter is 62.7 mm (2.469 in.) or
less, replace outer rotor (Fig. 60).
If inner rotor measures 20.9 mm (0.825 in.) or less,
replace inner rotor and shaft assembly (Fig. 61).
Slide outer rotor into pump body. Press rotor to the
side with your fingers and measure clearance
between rotor and pump body (Fig. 62). If clearance
is 0.356 mm (0.014 in.) or more, replace oil pump
assembly.
Install inner rotor and shaft into pump body. If
clearance between inner and outer rotors is 0.203
mm (0.008 in.) or more, replace shaft and both rotors
(Fig. 63).
Place a straightedge across the face of the pump,
between bolt holes. If a feeler gauge of 0.102 mm
(0.004 in.) or more can be inserted between rotors
and the straightedge, replace pump assembly (Fig.
64).
Inspect oil pressure relief valve plunger for scoring
and free operation in its bore. Small marks may be
removed with 400-grit wet or dry sandpaper.The relief valve spring has a free length of approx-
imately 49.5 mm (1.95 in.). The spring should test
between 19.5 and 20.5 pounds when compressed to
34 mm (1-11/32 in.). Replace spring that fails to meet
these specifications (Fig. 65).
If oil pressure was low and pump is within specifi-
cations, inspect for worn engine bearings or other
reasons for oil pressure loss.
ASSEMBLY
(1) Install pump rotors and shaft, using new parts
as required.
(2) Position the oil pump cover onto the pump
body. Tighten cover bolts to 11 N´m (95 in. lbs.)
torque.
Fig. 60 Measuring Outer Rotor Thickness
Fig. 61 Measuring Inner Rotor Thickness
Fig. 62 Measuring Outer Rotor Clearance in
Housing
1 - PUMP BODY
2 - OUTER ROTOR
3 - FEELER GAUGE
Fig. 63 Measuring Clearance Between Rotors
1 - OUTER ROTOR
2 - FEELER GAUGE
3 - INNER ROTOR
BR/BEENGINE 3.9L 9 - 51
OIL PUMP (Continued)

(3) Install the relief valve and spring. Insert the
cotter pin.
(4) Tap on a new retainer cap.
(5) Prime oil pump before installation by filling
rotor cavity with engine oil.
INSTALLATION
(1) Install oil pump. During installation, slowly
rotate pump body to ensure driveshaft-to-pump rotor
shaft engagement.(2) Hold the oil pump base flush against mating
surface on No. 4 main bearing cap. Finger-tighten
pump attaching bolts. Tighten attaching bolts to 41
N´m (30 ft. lbs.) torque.
(3) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
INTAKE MANIFOLD
DESCRIPTION
The aluminum intake manifold (Fig. 66) is a single
plane design with equal length runners. This mani-
fold uses a separate plenum pan and gasket, there-
fore the plenum gasket is servicable. It also uses
separate flange gaskets and front and rear cross-over
gaskets. Extreme care must be used when sealing
the gaskets to ensure that excess sealant does not
enter the intake runners causing a restriction.
OPERATION
The intake manifold, meters and delivers air to the
combustion chambers allowing the fuel delivered by
the fuel injectors to ignite, thus producing power.
Fig. 64 Measuring Clearance Over Rotors
1 - STRAIGHT EDGE
2 - FEELER GAUGE
Fig. 65 Proper Installation of Retainer Cap
1 - RETAINER CAP
2 - CHAMFER
3 - COTTER KEY
Fig. 66 Intake Manifold with Tightening SequenceÐ
3.9L Engine
9 - 52 ENGINE 3.9LBR/BE
OIL PUMP (Continued)