Spark Plug Type 2001 Dodge Ram 3.9L

Two of the most common questions we get are; what type of spark plug for my 2001 Dodge Ram 1500 3.9-liter V6 engine, or what brand of spark plug is best for my full-size pickup truck? The best kind or type of spark plug has already been determined by DaimlerChrysler automotive corporation. Daimler AG has specified in their 2001 Dodge Ram dealership service manual which plug type to use for each engine model and the plug electrode gap, or spark plug gap. 

Spark Plug Description

A spark plug is an electrical device inserted into an opening on a cylinder head so as to emit a spark of electricity and ignite the explosive mixture in an internal-combustion engine. As the name implies, “spark” emit sparks of electricity and “plug” fills a threaded hole on the cylinder head. The electric spark causes the compressed fuel and air to explode turning mechanical power into motion.

Spark Plug Type

The vehicle manufacturer recommend that newer Dodge Ram pickup trucks use NGK brand spark plugs. However, the service department strictly advise the use of Champion RC12LC4 copper plus replacement spark plugs for 2001 3.9-liter engines.

3.9L V6 RC12LC4 1.01 mm (.040 in.)
5.2L/5.9L V8 RC12LC4 1.01 mm (.040 in.)
8.0L V10 QC9MC4 1.14 mm (.045 in.)

The printed numbers and letters on a spark plug define its classification, design and other characteristics. The letter “R” on a 3.9L plug identifies it as a resistor type spark plug. The “Q” refers to inductive type spark plugs, which are used on 8.0L V-10 engines. Additional characters specify the shell type, heat range application, gap dimension and firing end design.

Torque Specifications

DESCRIPTION N·m Ft. Lbs. In. Lbs.
Spark Plugs (all engines) 41    –     30

Never install a spark plug of a different type. A spark plug that is too long can cause severe engine damage. A longer spark plug can make contact with moving parts and brake off or flatten the electrode. A spark plug that is shorter than what is recommended will result in poor fuel economy and spark plug fouling.

Gavin Whiteley

Hi, I'm Gavin, ASE Master automotive technician with 15+ years of experience. I am a lead mechanic for a high-volume dealership service department. If you have a repair question, post it in the comment box and I will do my best to answer it. Be certain to provide as much detail as possible so that I can better answer your question.

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