P0308 Dodge Ram 1500 – Causes And Solutions

The P0308 Dodge Ram 1500 is a common issue that can cause various problems with the engine’s performance.

There are several causes and solutions for this error that can help drivers get their vehicles back to running smoothly. Let’s read on to learn how to fix it.

What Is P0308 Dodge Ram 1500?

p0308 dodge ram 1500
P0308 Dodge Ram 1500

The P0308 error code on a Dodge Ram 1500 is related to the engine’s ignition system and indicates a #8 cylinder misfire on the engine.

Specifically, this code suggests that the combustion process in this cylinder is not happening as it should.

It could happen due to various issues related to the engine’s ignition system, such as a problem with the spark plug, ignition coil, fuel injector, or other related components.

A misfire in some cylinders can cause reduced engine power and decreased fuel economy, leading to further engine damage if not addressed.

Typically, this may occur several times before a misfire code is saved and the check engine light becomes activated.

What Are The Causes Of The P0308 Dodge Ram 1500?

The culprits behind the P0308 code on the Dodge Ram 1500 may include bad spark plugs, faulty ignition coils, malfunctioning fuel injector, vacuum leak, low compression, faulty PCM, defective camshaft sensor, and faulty spark plug wires.

Defective Spark Plugs

These plugs are in charge of sparking the fuel in the cylinders and igniting the engine. If the spark plugs are worn, dirty, or damaged, they can spark a misfire, triggering the code po308.

Over time, spark plugs can wear out and need to be replaced.

Bad Ignition Coils

Ignition coils help to generate the high voltage for creating a spark in the spark plug.

If an ignition coil is fouled, it may result in an ignition failure in the corresponding cylinder, leading to the P0308 code. Ignition coils can fail due to age, heat, or other factors.

Malfunctioning Fuel Injector

Fuel injectors play a role in delivering gas to the engine’s cylinders. If a fuel injector is not functioning correctly, it can lead to a lean or rich fuel mixture, leading to a misignition.

Contamination, wear and tear, and fuel quality can lead to a faulty fuel injector, causing the P0308 code.

Vacuum Leak

A vacuum leak occurs when air enters the engine’s intake system from an unintentional source. It can cause a lean air/fuel combination, which can end up with a misfire.

Vacuum leaks can stem from a variety of issues, including bad valve cover gasket, and damaged vacuum lines or gaskets.

Low Compression

Low compression in a cylinder can also trigger the P0308 code due to many issues, including worn piston rings, damaged valves, or a blown head gasket.

Faulty PCM

The Powertrain Control Module (PCM) helps to control the engine’s ignition system. Electrical overload and heat can make it function improperly, and the P0308 code will pop up.

Defective Camshaft Sensor

The camshaft sensor is in charge of providing the engine control module (ECM) with information about the position of the camshaft, which is used to control the timing of the engine’s intake and exhaust valves.

If the camshaft sensor malfunctions, the ECM won’t be able to accurately adjust the timing of the engine’s valves, leading them not to ignite properly in the cylinders.

Faulty Spark Plug Wires

The spark plug wires contribute to electrical current delivering from the ignition coil to the spark plugs, which ignite the fuel in the cylinders.

If the spark plug wires are damaged, worn, or not connected properly, it can end up with a weak or intermittent spark and finally a misfire in one or more cylinders.

How Do You Fix A Cylinder 8 Misfire?

code p0308 dodge ram
Way To Repair A Cylinder 8 Misfire

Check The Ignition System

First, I checked the ignition system by resetting the trouble codes and transferring the coil pack, wire, and plug from cylinder 8 to a different cylinder.

If a different P030X code appears, it indicates that coil packs, wires, or plugs are defective.

This is because moving the components changes the cylinder where the trouble code is registered. Once you have identified the faulty component, you can replace it or have it tested.

It is a simple and cost-effective method of diagnosing ignition component issues.

Check Each Component And Replace It If Needed

Then, I looked at the spark plugs to see if they needed to be replaced. You should replace them if they are worn out, damaged, or fouled.

My spark plugs at that time were still in good condition, so the next step was to inspect the ignition coils. I used a multimeter to check the resistance of the coils. If a coil goes wrong, replace it.

I continued to examine the vacuum leaks in the intake manifold or hoses.

Inspect all vacuum connections and ensure they are properly tightened, as loose connections can cause vacuum leaks. If the hose or the vacuum line is damaged, replace it with a new one.

What Are The Common Symptoms Of The P0308?

cylinder 8 misfire causes
Some Symptoms Of The P0308

The most common symptoms associated with P0308 code Dodge Ram 1500 I’ve ever encountered include difficult engine starting, rough engine idle, or irregular engine operation.

Besides, engine shutdown during acceleration, reduced engine power during driving, and reduced fuel economy can be obvious signs of this problem.

If you experience any of these symptoms, having your vehicle diagnosed and repaired as soon as possible is important to avoid potential engine damage and further performance issues.


What Is The Cost Of Repairing Code P0308 Dodge Ram?

The cost of repairing the code P0308 is $154.99 for Ford cars, $154.99 for Toyotas, and $164.99 for BMWs. These include both labor costs and repair of broken parts.

What Are Some Common Mistakes When Checking The P0308 Code?

One common mistake I usually make when checking the P0308 Dodge code is immediately replacing the spark plugs without thoroughly checking every aspect of the issue.

While fouled spark plugs can indeed cause the code to appear, other issues, such as bad ignition coils, malfunctioning fuel injectors, or low compression, can also be at fault.

Diagnosing and addressing all possible causes is crucial to resolve the issue completely.

Is P0308 Code A Serious Problem?

Yes, the P0308 code is a serious problem as it can wreak havoc on the engine.

If left unresolved, this can lead to several issues, such as decreased fuel system efficiency, rough idling, loss of power, and even engine damage.

Besides, the vehicle may sometimes break down and leave drivers stuck on the road.

It’s important to address this issue promptly to prevent more severe damage and ensure safe and reliable driving.


In conclusion, the P0308 Dodge Ram 1500 is a serious issue that requires prompt attention to prevent further damage to the engine.

By identifying and addressing the root cause, such as faulty spark plugs, bad ignition coils, or low compression, drivers can effectively fix the issue and restore their vehicle’s performance.

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