Symptoms of Bad Ignition Coil In A Truck

The ignition system is an essential part of every petrol engine truck, and the ignition coil is one of its components. The ignition coil supplies adequate current to initiate a spark in the spark plugs. It is between the battery and the spark plugs and therefore receives the current from the battery before delivering it to the spark plugs. If it fails, your truck may not start, but before it dies completely, it will develop the symptoms below.

The Appearance of the Engine Check Light

When your engine becomes faulty, the ECU will light the engine check light on your truck’s dashboard. The activities of the ignition coil directly affect the engine. Therefore when the engine is faulty, the check light will appear.

Engine Misfiring and Backfiring

In the initial stages at the beginning of ignition coil failure, you will notice engine backfires. It happens due to unburnt fuel within the cylinder that flows to the exhaust pipe.

You will also feel a bad smell of fuel, and your truck will emit black smoke. When you note such from your truck, consider checking the ignition coil and correct it as soon as possible.

Stalling Truck

If your truck has only one ignition coil, which is common in old trucks, it will stall on the highway if it is faulty. When driving at an average speed and your truck stops abruptly, your ignition might be faulty. 

A faulty ignition coil will deliver inadequate current to the spark plug. When this happens, the fuel and air in the combustion chamber will not ignite, making your engine stop.

Increase in Fuel Consumption

Faulty ignition causes engine misfires. As this happens, fuel pours out to the exhaust pipe, which increases fuel consumption. When the rate at which your truck consumes fuel goes up, consider checking the condition of the ignition coil.

Funny Engine Noises

A faulty ignition coil does not generate adequate voltage for the spark plugs causing a spark in the engine. As a result, your engine will strain to initiate combustion. Your truck will sound like a tractor if a spark delays in a single cylinder. When you hear any funny sound like the engine is straining, consider checking the condition of the ignition cylinder.

Truck Not Starting

When the ignition is completely dead, your truck’s engine will not start. Instead, you will hear a clicking sound whenever you try to start the engine. If such happens, it might be the ignition coil or the entire ignition system. Such a problem is common in old trucks with only a single ignition coil for all the cylinders.


When the engine starts and runs, spark plugs are essential as they are the source of heat that causes combustion in the cylinders. However, the spark plugs need adequate voltage from the battery. The ignition coil ensures the spark plugs receive the necessary voltage.

If the coil springs become faulty before they cease functioning, your truck will develop symptoms like the ones discussed above. 

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