Will Bad Spark Plugs Cause Car not to Start

Spark plugs are little items or devices that are responsible for the production of the electric spark that ignites the mixture of air and fuel in the combustion chamber.

Over time, it is possible for these plugs to wear out and be less effective. At this point, you will need to replace them because using bad spark plugs in your car has many disadvantages. But the question is, will bad spark plugs cause the car not to start? 

Yes, bad spark plugs can cause a car not to start because the spark plugs are responsible for producing the needed spark to ignite the engine. Therefore, a failed spark plug may hinder a car from starting.

Will Bad Spark Plugs Cause Car Not to Start?

In many cases, it is possible for a car with bad, damaged, foul, or worn-out spark plugs not to start. Because the spark plugs are responsible for producing the needed spark to ignite the engine, a failed spark plug might hinder a car from starting.

In this case, you should replace the spark plugs as soon as you notice any of the symptoms of a failing spark plug. It is not safe for you to drive with bad spark plugs because your engine will have problems. Failure to change your spark plugs can cause many things to happen.

What are Considered Bad Spark Plugs?

Bad spark plugs are often referred to as faulty, fouled, or damaged spark plugs. A bad spark plug is a plug that is covered with materials such as carbon, fuel, or oil. It can also be a plug that is damaged from overheating.

If you drive with bad spark plugs, you risk damaging other components of your car’s engine. The spark plugs in your engine should be cleaned regularly to prevent damage to the electrodes to maintain optimum performance.

How do you know when a spark plug is faulty? There are some noticeable symptoms which include loss of power, engine misfires, poor fuel economy, slow acceleration, and difficulty in starting the car.

We need to understand the role of spark plugs for us to know why it is dangerous when it gets faulty. A spark is needed to ignite the fuel-air mixture in the combustion chamber. Spark plugs provide that needed spark and so they are so important in the engine.

Every vehicle needs some kind of spark plug designed with specific materials and an approved spark plug gap to be set by a mechanic during the installation process.

A spark plug in normal working conditions will burn fuel well, but a faulty spark plug will make it difficult for the vehicle to start.

Listed below are some of the symptoms of faulty spark plugs;

1. Engine Misfires

Whenever an engine misfires, it is due to problems in the ignition system. In some modern vehicles, it can be caused by faulty sensors.

But it can also be caused by a damaged spark plug. You would know when a misfiring engine by the stumbling sounds produced by the engine.

If you do not repair a misfiring engine, emissions from the exhaust will increase and the engine power will decrease massively. The fuel economy will also drop.

2. Slow Acceleration

An issue with the ignition system is most likely the cause of slow acceleration in vehicles. Sometimes, a bad spark plug might be the reason behind it though.

When the materials used in producing a spark plug wear out, the plug loses its effectiveness and the acceleration of the vehicle is affected.

3. Rough Idling

Bad spark plugs cause the engine to sound jittery while it is idling. When driving, you will feel a vibrating sound from your engine. That is a sign of bad spark plugs, it causes the cylinder to misfire when the engine is idling, thereby causing rough idling.

4. Surges of the Engine

It is possible you notice that your engine hesitates when you press on the throttle. It is a case of the engine not working as it should.

It may experience a surge in power and then drop all of a sudden. A problem with the spark plug can be responsible for that.

What happens is that the engine has taken in more air than it should take and so it causes a delay in the power delivery.

What Causes Spark Plugs to Go Bad?

What are the causes of failure or bad spark plugs? They are:

1. Oil in Combustion Chamber

The main cause of a bad spark plug is the flow of engine oil into the combustion chamber. The tip of a spark plug can get really oily and dirty when oil flows into the combustion chamber as a result of leakage. This causes damage to the spark plug.

If you drive an older vehicle and you notice that the oil in your car is consumed faster than normal, it could be an indicator that the spark plugs are damaged.

2. Carbon Buildup

Carbon in the form of noticeable black and dry soot on the electrodes indicates a fouled spark plug. When there is carbon residue on the insulator tip of a spark plug, it causes the lifespan to be reduced drastically.

This will cause many problems in the car engine such as decreased acceleration, rough idling, misfiring of the engine, etc.

Carbon buildup on spark plugs is caused by an excess mixture of fuel and air, dirty fuel injectors, idling for too long, dirty air filter, and many more.

3. Overheating

Constant overheating of spark plugs can damage them severely. Overheating is caused by a faulty cooling system and pre-ignition.

When pre-ignition occurs, it leads to the accumulation of heat in the combustion chamber which eventually leads to total failure of the spark plugs.

Also, when a cooling system fails, it makes the spark plugs and the engine overheat. The electrodes of the spark plug are affected by this and they will wear out faster.

4. Unsuitable Gapping of Spark Plugs

The side electrodes and center electrodes of the spark plugs need to be gapped properly by measuring accurately. If the gap is accurate, your car’s engine will work at optimal performance.

Not only that, having the right gap between the electrodes makes the arcing take place at the right voltage which can ignite the fuel and produce the combustion to make the engine run.

If the gap is not suitable or proper, excess pressure will be placed on the tip of the spark plug which will make it wear out and erode quickly.

Benefits of Good Spark Plugs

Benefits of good spark plugs:

  • Smooth Start: When you switch on the ignition of your car with good spark plugs, you will notice a smooth process. Everything will work as normal; you won’t experience those difficult starts you get when you had bad spark plugs.
  • Fully Functional Combustion Process: Good spark plugs help in having a fully working combustion process. There will be fewer performance issues in your car.
  • Increased Fuel Efficiency: Bad spark plugs reduce the fuel efficiency of an engine by 30% as claimed by the National Institute for Automotive Service Excellence. With good spark plugs, the fuel economy of your car will increase and in the long run, you will spend less money.
  • Reduced Harmful Emissions: Good spark plugs reduce the emissions from your vehicle. This means that there will be less air pollution in the environment.

Final Thoughts

To conclude, spark plugs are responsible for a lot of processes in your car. When they become faulty, the overall engine performance will drop. You will observe some signs when driving with a bad spark plug. Replace them as soon as possible to avoid worst-case scenarios.