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3.9L ENGINE
9 - 17
3.9L
ENGINE SERVICE PROCEDURES
INDEX
page
Camshaft
31
Crankshaft
38
Crankshaft Main Bearings
39
Crankshaft Rear
Oil
Seals
. 40
Cylinder Block
41
Cylinder Head Cover
. , 21
Cylinder Heads
. 22
Distributor
33
Engine
Assembly .........................
20
Engine
Front Mounts
17
Engine
Rear Mount
18
Front Crankshaft
Oil
Seal Replacement ........
31
GENERAL INFORMATION
The 3.9 Liter (238 CID) six-cylinder engine is a
V-Type, lightweight, single cam, overhead valve en gine with hydraulic roller tappets (Fig. 1).
Engine
Type
90° V-6 OHV
Bore
and Stroke 99.3
x
84.0 mm (3.91 x3.31
in.)
Displacement 3.9L (238 cu.
in.)
Compression
Ratio
9.1:1
Torque 305 N-m (225
ft.
lbs.)
@
3,200
rpm
Firing Order.... 1-6-5-4-3-2
Lubrication
Pressure
Feed-Full Flow
Filtration
Engine
Oil
Capacity 3.8L (4.0 Qts)
with Filter
Cooling
System
Liquid Cooled-Forced
Circulation
Cooling Capacity 14.3L
(15.1
Qts)
Cylinder Block Cast Iron
Crankshaft Nodular Iron
Cylinder Head
Cast
Iron
Combustion Chambers "Fast
Burn"
Design
Camshaft Nodular
Cast
Iron
Pistons
Aluminum Alloy
w/Strut
Connecting
Rods
Forged Steel
J9309-29
Fig.
1
Engine
Description
This engine is designed for unleaded fuel. Engine lubrication system consists of a rotor type
oil pump and a full flow oil filter.
The cylinders are numbered from front to rear; 1,
3,
5 on the left bank and 2, 4, 6 on the right bank.
The firing order is
1-6-5-4-3-2
(Fig. 2).
The engine serial number is stamped into a ma
chined pad located on the left, front corner of the cyl
inder block. When component part replacement is
necessary, use the engine type and serial number for
reference (Fig. 3).
page
General
Information
17
Hydraulic Tappets
27
Oil
Pan 34
Oil Pump
34
Piston
/
Connecting
Rod
Assembly
36
Rocker
Arms
21
Specifications—3.9L Engine
43
Timing Chain Cover
29
Valve Stem Seal
/
Spring Replacement ........
27
Valve Timing
28
Valves
/
Valve Springs
25
Vibration
Damper
29
J9309-26
Fig.
2 Firing Order i M 3.9L T xxxx
XXXXXXXX
X
=
Last Digit
of
Model Year
M
=
Plant -
M
Mound
Road
S
Sabillo
T Trenton
K
Toluca
3.9L
=
Engine Displacement
T
=
Usage
-
T Truck
XXXX
=
Month/Day
XXXXXXXX
- Serial Code -
Last
8
Digits of
VIN
No.
J9209-72
Fig.
3
Engine
identification
Number
ENGINE FRONT MOUNTS
REMOVAL (1) Disconnect the negative cable from the battery.
