AMC 150 (2.5L) Inline-4 Engine

The AMC 2.5L Inline-4 engine was developed by American Motors Corporation (AMC) that was used in AMC, Jeep, and Dodge vehicles. The engine block and head are both made of cast iron, and features an Overhead Valve (OHV) design with 2 valves per cylinder. Production began in 1984 and seized in 2002.

AMC 2.5L I4 in a Wrangler YJ

The AMC Inline-4 engine began production after 3 years of development within AMC. It was specifically designed to be used in Jeeps, and was not designed as a standard passenger car engine.

The 2.5L was produced between 1984-2002. Just like the other inline engines AMC created, it was considered reliable and inexpensive to repair. The 1984 and 1985 model years were paired with a single barrel carburetor. In 1986 the engine was paired with the Renix computer system and changed over to Throttle-body Fuel Injection (TBI) which injected fuel into the throttle body.. In 1991, the engine fuel delivery system was again updated to the Mopar Sequential Multi-Point Fuel Injection system (MPFI), which injects fuel above each cylinder’s intake valve.

This engine was used in a variety of vehicles throughout AMCs lineup – but here are some of the Jeeps you can find it in:

  • 1983-1984 Jeep DJ-5M
  • 1984-1986 Jeep CJ-7
  • 1984-2000 Jeep Cherokee
  • 1986-1992 Jeep Comanche
  • 1987-2002 Jeep Wrangler

Engine Power Specifications

YEARHPTQ
1984-1985105hp @ 5000rpm132lb-ft @ 2800rpm
1986-1990 (TBI)117hp @ 5000rpm135lb-ft @ 3500rpm
1991-2002 (MPFI)120hp @ 5250rpm139lb-ft @ 3250rpm

Oil Types and Capacities

ViscosityAbove 0°F: 10W-30
Below 60°F: 5W-30
Capacity4 qts (3.8L)
Oil FilterMopar 5281090AB
WIX 51085
Drain Plug Torque30ft-lbs

Tune-up Parts

Spark Plug1984-1985: Champion 82
1986-1998: Champion 412
1999-2002: Champion 438
Plug Wires1984-1990: NGK 53292
1991-2002: NGK 53186

Common Problems

Lifter Tick

Lifter tick is a common issue on these engines. While essentially harmless, many people do not enjoy the sound of the top of the engine slightly ticking when running. Besides replacing rockers and lifters, the only solution I’ve seen to work is to use a zinc additive in your oil or switch to an oil type that includes higher levels of zinc. One of the most recommended oils to use in the 2.5L engine (and 4.2L & 4.0L for that matter) is the Shell Rotella Diesel Engine Oil. The oil works great in the engine and includes lots of Zinc. As a result, this engine oil usually reduces lifter tick noise.

Modification

Since the 2.5L engine is a low-powered engine, it’s not common that people modify them. A common upgrade to the engine would be to swap it out for a 4.0L engine.

Downloads

Engine Fluids

EngineFluid TypeCapacity
AMC 2.5L I4Above 0°F: 10W-30
Below 60°F: 5W-30
4.0 qts
AMC 4.0L I6Above 0°F: 10W-30
Below 32°F: 5W-30
6.0 qts
GM 2.5L I4Above 0°F: 10W-30
Below 0°F: 5W-30
3.0 qts
Renault 2.1Ltbdtbd
VM Motori 2.5Ltbdtbd

Transmission Fluids

TransmissionFluid TypeCapacity
Chrysler A904 3-Speed
Aisin-Warner AW-4 4-Speed
Chrysler 30RH 3-Speed
Borg-Warner T-4 4-Speed ATF Dexron II1.75qts
Aisin-Warner AX4 4-Speed75W-90 GL3 or GL4
10W-30 Motor Oil
2WD: 3.7qts
4WD: 3.5qts
Borg-Warner T-5 5-SpeedATF Dexron II1.75qts
Aisin-Warner AX5 5-Speed75W-90 GL3 or GL4
10W-30 Motor Oil
2WD: 3.7qts
4WD: 3.5qts
Peugeot BA-10/5 5-Speed
Aisin-Warner AX15 5-Speed75W-90 GL3 or GL4
10W-30 Motor Oil
2WD: 3.32qts
4WD: 3.27qts
New Venture Gear NV3550 5-SpeedMopar MT Fluid
SAE 30W Oil
3.3qts

Axle Fluids

AxleFluid TypeCapacity
Dana 3075W-90
75W-140 (towing)
1.26qts
Dana 3575W-90
75W-140 (towing)
1.75qts
Dana 4475W-90
75W-140 (towing)
2.00qts
Chrysler 8.2575W-90
75W-140 (towing)
2.11qts

Transfer Case Fluids

Transfer CaseFluid TypeCapacity
NP207
NP228/229
NP231
NP242

This will close in 0 seconds

4.0L

This will close in 0 seconds