Engine Specifications

I6, 4.0 liter engine

Displacement
243 cubic inches
Cylinder numbers (front to rear)
1-2-3-4-5-6
Firing order
1-5-3-6-2-4
Spark Plug gap
0.033 to 0.038
Ignition timing
9 to 11 degrees
Idle speed (auto)
600 +/- 70 rpm

(manual)

680 +/- 70 rpm
Engine oil
API SE of SF
Above 0°F/-18°C - 10W30, Below 60°F/16°C - 5W30
Oil capacity
6 quarts (5.7 liters)
Automatic Transmission Fluid
Mercon ATF
ATF Capacity
4 quarts

I4, 2.5 liter engine

Displacement
150 cubic inches
Cylinder numbers (front to rear)
1-2-3-4
Firing order
1-3-4-2
Spark Plug gap
0.033 to 0.038
Ignition timing
9 to 11 degrees
Idle speed (auto)
600 +/- 70 rpm

(manual)

680 +/- 70 rpm
Engine oil
API SE of SF
Above 0°F/-18°C - 10W30, Below 60°F/16°C - 5W30
Oil capacity
4 quarts (3.8 liters)
Automatic Transmission Fluid
Mercon ATF
ATF Capacity
4 quarts

I6, 4.2 liter engine (not fuel injected)

Displacement
256 cubic inches
Cylinder numbers (front to rear)
1-2-3-4-5-6
Firing order
1-5-3-6-2-4
Spark Plug gap
0.033 to 0.038
Ignition timing
9 to 11 degrees
Idle speed (auto)
600 +/- 70 rpm

(manual)

680 +/- 70 rpm
Engine oil
API SE of SF
Oil capacity
6qts
Automatic Transmission Fluid
Mercon ATF
ATF Capacity
4qts

Engine Transmission Initial Timing at
Curb Idle
(Vacuum Hose
Disconnected)

Curb Idle Speed RPM

Set To
Acceptable
Range
Set To
Acceptable
Range
258
1 Barrel carb
Manual

(49)

850
(49)
750
950
10°
(Alt)

12°
600
(Alt)
500
700

(Cal)

10°
850
(Cal)
750
950
Automatic

(49)

10°
550
(49)
450
650
10°
(Alt)

12°
550
(Alt)
450
650

(Cal)

10°
550
(Cal)
450
650
258
2 Barrel carb
Manual

650
550
750
Automatic

550
450
650

 

* Disclaimer: Specifications/descriptions/data provided for informational purposes only. If it's important, make sure you consult with an authorized Jeep mechanic/factory service center. The site operator claims no responsibility for damage or losses incurred as a result of using information posted here.