2007 Wrangler JK Factory Service Manual 9 - ENGINE

SPECIFICATIONS

3.8L ENGINE


GENERAL DESCRIPTION

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Engine Type
 
60° V-6 Engine
 
Number of Cylinders
 
6
 
Displacement 3.8L
 
3.8 Liters
 
231 cu. in.
 
Bore 3.8L
 
96.0 mm
 
3.779 cu.in.
 
Stroke
 
87 mm
 
3.425 in.
 
Compression Ratio 3.8L
 
-
 
9.6:1
 
Firing Order
 
-
 
1-2-3-4-5-6
 
Compression Pressure-Minimum
 
689.5 kPa
 
100 psi.
 
Cylinder Compression (Max. Difference Between Cylinders
 
-
 
25%
 


CYLINDER BLOCK

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Cylinder Bore Diameter (Standard) 3.8L
 
95.993-96.007 mm
 
3.7792-3.780 in.
 
Out of Round (Service Limits)
 
0.076 mm
 
0.003 in.
 
Taper (Service Limits)
 
0.051 mm
 
0.002 in.
 
Lifter Bore Diameter
 
22.980-23.010 mm
 
0.905-0.906 in.
 
Deck Surface Flatness (Max.)
 
0.1 mm
 
0.004 in.
 


CRANKSHAFT

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Connecting Rod Journal Diameter
 
57.979-58.005 mm
 
2.2827-2.2837 in.
 
Main Bearing Journal Diameter
 
63.993-64.013 mm
 
2.5194-2.5202 in.
 
Journal Out-of-Round (Max.)
 
0.025 mm
 
0.001 in.
 
Journal Taper (Max.)
 
0.025 mm
 
0.001 in
 
End Play
 
0.09-0.24 mm
 
0.0036-0.0095 in.
 
Wear Limit
 
0.381 mm
 
0.015 in.
 
Main Bearing Diametrical Clearance 1-2-3-4
 
0.011-0.055 mm
 
0.0005-0.0022 in.
 
Wear Limit
 
0.076 mm
 
0.003 in.
 


CONNECTING RODS

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Bearing Clearance
 
0.019-0.065 mm.
 
0.017-0.020 in.
 
Wear Limit
 
0.074 mm
 
0.003 in.
 
Side Clearance
 
0.13-0.32 mm
 
0.005-0.013 in.
 
Wear Limit
 
0.38 mm
 
0.015 in.
 


PISTONS

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Piston Diameter 3.8L-Measured 33.01 mm (1.30 in) From Piston Top
 
95.968-95.998 mm.
 
3.778-3.779 in.
 
Clearance in Bore @ Size Location (New)
 
-0.005-0.039 mm
 
-0.0002–0.0015 in.
 
Weight 3.8L
 
426 ± 5 grams
 
15.03 ± 0.1764 oz.
 


PISTON PINS

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Type
 
Press Fit in Rod (Serviced as a Assembly)
 
Clearance in Piston @ 21C (70°F)
 
0.006-0.019 mm
 
0.0002-0.0007 in.
 
Clearance in Connecting Rod
 
Interference Fit
 
Diameter
 
22.87-22.88 mm
 
0.9007-0.9009 in.
 
Length 3.8L
 
71.25-71.75 mm
 
2.805-2.824 in.
 


PISTON RINGS

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Ring End Gap
 
   
Top Compression Ring
 
0.18-0.38 mm
 
0.007-0.015 in.
 
Second Compression Ring
 
0.28-0.57 mm
 
0.011-0.022 in.
 
Oil Control (Steel Rails)
 
0.23-0.78 mm
 
0.009-0.030 in.
 
Wear Limit-Compression Rings
 
1.0 mm
 
0.039 in.
 
Wear Limit-Oil Control Steel Rails
 
1.88 mm
 
0.074 in.
 
Ring Side Clearance
 
   
Top Compression Ring 3.8L
 
0.030-0.069 mm
 
0.0012-0.0027 in.
 
Second Compression Ring 3.8L
 
0.041-0.085 mm
 
0.0016-0.0033 in.
 
Oil Ring (Steel Ring)
 
0.039-0.200 mm
 
0.0015-0.0078 in.
 
Wear Limit- Top Ring
 
0.10 mm
 
0.004 in.
 
Wear Limit-2nd Ring
 
0.13 mm
 
0.005
 
Wear Limit Oil Ring Pack
 
0.266 mm
 
0.009
 
Ring Width-Top Compression Ring 3.8L
 
1.175-1.190 mm
 
0.0462-0.0468
 
Ring Width-2nd Compression Ring 3.8L
 
1.46-1.49 mm
 
0.0575-0.058 in.
 
Ring Width-Oil Ring (Steel Rails) 3.8L
 
0.435-0.510 mm
 
0.017-0.020
 


CAMSHAFT

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Journal Diameter
 
 
#1
 
50.724-50.775 mm
 
1.997-1.999 in.
 
#2
 
50.317-50.368 mm
 
1.9809-1.9829 in.
 
#3
 
49.936-49.987 mm
 
1.9659-1.9679 in.
 
#4
 
49.530-49.581 mm
 
1.9499-1.9520 in.
 
Bearing Clearance-Diametrical
 
0.025-0.101 mm
 
0.001-0.004 in.
 
Bearing Clearance (Max.Allowable)
 
0.127 mm
 
0.005 in.
 
End Play
 
0.254-0.508 mm
 
0.010-0.020 in.
 
Camshaft Bearing Diameter
 
 
#1
 
50.800-50.825
 
1.9999-2.0009 in.
 
#2
 
50.393-50.419 mm
 
1.9839-1.9849 in.
 
#3
 
50.013-50.038 mm
 
1.9690-1.9699 in.
 
#4
 
49.606-49.632 mm
 
1.9529-1.954 in.
 
Exhaust Valve Timing
 
 
Closes-3.8L (ATDC)
 
-
 
18°
 
Opens-3.8L (BBDC)
 
-
 
46°
 
Duration-3.8L
 
-
 
244°
 
Intake Valve Timing
 
 
Closes-3.8L (ABDC)
 
-
 
63°
 
Opens-3.8L (ATDC)
 
-
 

 
Duration-3.8L
 
-
 
242°
 
Valve Overlap-3.8L
 
-
 
17°
 


HYDRAULIC LIFTER

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Type
 
Hydraulic Roller
 
Outside Diameter
 
22.949-22.962 mm
 
0.903-0.904 in.
 
Clearance in Block
 
0.020-0.061 mm
 
0.0007-0.0024 in.
 


CYLINDER HEAD

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Gasket Thickness (Compressed)
 
0.65-0.75 mm
 
0.0007-0.0024 in.
 


VALVES

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Face Angle-Intake
 
-
 
45-45.5°
 
Face Angle-Exhaust
 
-
 
45-45.5°
 
Head Diameter-Intake
 
47.87-48.13 mm
 
1.88-1.89 in.
 
Head Diameter-Exhaust
 
35.37-35.63 mm
 
1.39-1.40 in.
 
Valve Lift (Zero Lash)-Intake and Exhaust-3.8L
 
11.0 mm
 
0.433 in.
 
Valve Length-Intake
 
125.84-126.6 mm
 
4.95-4.98 in.
 
Valve Length-Exhaust
 
127.20-127.96
 
5.00-5.04 in.
 
Valve Stem to Tip Height (valve tip to spring seat washer)-Intake
 
48.1-49.7 mm
 
1.89-1.95 in.
 
Valve Stem to Tip Height (valve tip to spring seat washer)-Exhaust
 
48.53-50.09 mm
 
1.91-1.97 in.
 


VALVE SEAT

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Angle
 
-
 
44.5-45°
 
Run Out (Service Limits)
 
0.0762 mm
 
0.003 in.
 
Width-Intake and Exhaust
 
1.50-2.00 mm
 
0.057-0.078 in.
 


VALVE GUIDE

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Guide Bore Diameter (Std.)
 
6.975-7.00 mm
 
0.274-0.275 in.
 


VALVE MARGIN

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Intake
 
0.825-0.973 mm
 
0.032-0.038 in.
 
Exhaust
 
1.565-1.713 mm
 
0.061-0.067 in.
 


VALVE STEM DIAMETER

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Intake (Standard)
 
6.935-6.953 mm
 
0.2718-0.2725 in.
 
Exhaust (Standard)
 
6.906-6.924 mm
 
0.2718-0.2725 in.
 


VALVE STEM TO GUIDE CLEARANCE

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Intake
 
0.025-0.065 mm
 
0.001-0.0025 in.
 
Exhaust
 
0.059-0.094 mm
 
0.002-0.0037 in.
 
Max Allowable-Intake (Rocking Method)
 
0.247 mm
 
0.010 in.
 
Max Allowable-Exhaust (Rocking Method)
 
0.414 mm
 
0.016 in.
 


PUSH RODS

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Length
 
135.438 mm
 
5.33 in.
 


VALVE SPRING

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Free Length-Type A
 
51.4 mm
 
2.02 in.
 
Free Length-Type B
 
53.4 mm
 
2.10 in.
 
Wire Diameter Type A
 
3.95-4.77 mm
 
0.15-0.19 in.
 
Wire Diameter Type B
 
4.19-4.29 mm
 
0.16-0.17 in.
 
Number of Coils Type A
 
7.52
 
Number of Coils Type B
 
7.25
 
Spring Tension (Valve Closed) Type A
 
376.4-424.4 N @ 41.9 mm
 
84.6-95.6 lbs. @ 1.65 in.
 
Spring Tension (Valve Open) Type A
 
863.9-959.9 N @ 41.9 mm
 
194.2-215.8 lbs. @ 1.65 in.
 
Spring Tension (Valve Closed) Type B
 
377-423 N @ 41.9 mm
 
84.8-95.2 lbs. @ 1.65 in.
 
Spring Tension (Valve Open) Type B
 
880-962 N @ 30.91 mm
 
197.9-216.3 lbs. @ 122 in.
 
Installed Height
 
41.1-42.7 mm
 
1.61-1.68 in
 


LUBRICATION

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
At Curb Idle Speed* (Minimum with engine at operating temperature)
 
34.47 kPa
 
5 psi
 
At 3000 RPM
 
205-551 kPa
 
30-80 psi
 
Oil Filter By-Pass Valve Setting
 
62-103 kPa
 
9-15 psi
 
Oil Pressure Switch Actuating Pressure
 
14-28 Kpa
 
2-4 psi
 

CAUTION: *If pressure is ZERO at curb idle, DO NOT run engine at 3000 rpm.

 


OIL PUMP

DESCRIPTION
 
SPECIFICATION
 
Metric
 
Standard
 
 
Clearance Over rotors-Inner and Outer
 
0.10 mm
 
0.004 in.
 
Cover Out-Of-Flat (Max.)
 
0.025 mm
 
0.001 in.
 
Inner Rotor Thickness
 
7.64 mm
 
0.301 in.
 
Outer Rotor Thickness (Min)
 
7.64 mm
 
0.301 in.
 
Outer Rotor Clearance (Max)
 
0.039 mm
 
0.015 in.
 
Outer Rotor Diameter (Min)
 
79.95 mm
 
3.148 in.
 
Tip Clearance Between Rotors (Max)
 
0.20 mm
 
0.008 in.
 


SPECIFICATIONS - TORQUE


DESCRIPTION
 
N·m
 
Ft. Lbs.
 
In. Lbs.
 
Camshaft Sprocket—Bolt
 
54
 
40
 

 
Camshaft Thrust Plate—Bolts
 
12
 

 
105
 
Forged Connecting Rod Cap-Nuts
 
54 +¼ turn
 
40 +¼ turn
 

 
Cracked Connecting Rod Cap-Bolts
 
(Refer to 9 - ENGINE/ENGINE BLOCK/PISTON & CONNECTING ROD - INSTALLATION)
 
Crankshaft Main Bearing Cap-Bolts
 
41 +¼ turn
 
30 +¼ turn
 

 
Crankshaft Main Bearing Cap Cross Bolts (3.8L)
 
61
 
45
 

 
Crankshaft Oil Seal Retainer Rear-Bolts
 
12
 

 
105
 
Crankshaft Damper-Bolt
 
54
 
40
 

 
Cylinder Block Drain Plugs
 
20
 
15
 

 
Cylinder Head-Bolts
 
(Refer to 9 - ENGINE/CYLINDER HEAD - INSTALLATION)
 
Cylinder Head Cover-Bolts
 
12
 

 
105
 
Flex Plate to Crankshaft
 
88
 
65
 

 
Engine Mounting
 
(Refer to 9 - ENGINE/ENGINE MOUNTING)
 
Exhaust Manifold-Bolts
 
23
 

 
200
 
Intake Manifold - Lower-Bolts
 
23
 

 
200
 
Intake Manifold - Lower Gasket Retainer-Bolts
 
12
 

 
105
 
Intake Manifold Upper-Bolts
 
12
 

 
105
 
Lifter Yoke Retainer-Bolts
 
12
 

 
105
 
Oil Filter Attaching Fitting
 
54
 
40
 

 
Oil Cooler Attaching Fitting
 
27
 
20
 

 
Oil Filter
 
20
 
15
 

 
Oil Filter Adapter-Bolts
 
28
 

 
250
 
Oil Gallery Plug
 
27
 
20
 

 
Oil Pan—Bolts
 
12
 

 
105
 
Oil Pan Drain-Plug
 
27
 
20
 

 
Oil Pressure Switch
 
23
 

 
200
 
Oil Pump Cover Plate-Screws
 
12
 

 
105
 
Oil Pump Pick-up Tube-Bolt
 
28
 

 
250
 
Oil Dipstick Housing-Bolts
 
48
 
35
 

 
Rocker Arm Shaft-Bolts
 
23
 

 
200
 
Spark Plug
 
16
 
12
 

 
Thermostat Housing
 
12
 

 
105
 
Timing Chain Case Cover
 
     
—M8 Bolt
 
27
 
20
 

 
—M10 Bolt
 
54
 
40
 

 
Water Pump-Bolts
 
12
 

 
105
 
Water Pump Pulley-Bolts
 
28
 

 
250