How Long Can You Drive With Bad Spark Plugs : The Effects Of Spark Plug

Once the spark plugs become faulty, you will notice a decrease in fuel economy, low engine performance, misfires, idles, and so on. Moreover, there will be issues with the engine starting as well.

Now, how long can you drive with bad spark plugs? A car can still drive for a while with a faulty spark plug if not broken. In this situation, you may have some minor engine issues. But, you can’t drive with a broken plug since the engine cannot start.

However, we never recommend driving with a bad spark plug. You should change it once you find it faulty. Otherwise, it may cause permanent engine malfunction. To know more details about driving a car with faulty spark plugs, go through this article.

How Long Can You Drive With Bad Spark Plugs?

With bad spark plugs, your car may run for kilometers/miles, depending on the engine’s model. If the spark plug is not broken yet, you can drive around 500-1000 miles, depending upon the condition of the plug.

Before the plug is severed, the car can travel for a few miles in the first stage. Misfires at idle speed are the most likely problem in the first stages of troubleshooting your vehicle. Problems with acceleration and fuel mileage will arise as the gap between the plugs fills up.

The last stage of a bad spark plug is when it is broken completely. In this situation, you can hardly start the car. So, in this situation, you can not drive the car. So, before it is completely broken, go and change the plugs.

How Long Do Spark Plugs Last?

The life of spark plugs depends on the type of plugs and how you maintain them. Changing your spark plugs is something that is typically recommended every 30,000 miles. Here some spark plugs’ lifespans are mentioned below as per their types.

Spark Plugs (Types)Life Span (Miles)
Copper Spark Plug10,000 – 20,000
Silver Spark Plug15,000 – 20,000
Platinum or Iridium Spark Plug60,000
Extended Life Spark Plug (Long Life)1,00,000
High-End Iridium Spark Plug1,00,000
Extended Life Iridium Spark Plug1,20,000
Double Platinum Spark Plug1,00,000

Apart from the chart, the lifespan of a spark plug can be extended if you maintain it properly and clean it regularly. And the life span will decrease if you are not cautious enough with your car maintenance.

When To Replace The Spark Plug?

Bad spark plugs can cause a variety of issues, so it’s important to get them checked out if you see any of the signs. If it’s broken or malfunctioning, it has to be replaced. We recommend changing the spark plug even if it is in good condition if the vehicle has been driven for 70,000 to 80,000 miles.

Here are some common bad spark plug symptoms mentioned below. When you notice any of the following signs, it’s time to get a new spark plug.

  • Check Engine Light Flashing
  • Trouble With Engine Starting
  • Low Fuel Efficiency
  • Engine Idles
  • Unresponsive Acceleration
  • Engine Misfires

Apart from these, there are other possible indications of faulty spark plugs. Bad spark plugs can cause knock sensor code. Even more so, it can amplify the engine noise. If it remains unreplaced for so long, it can damage your engine.

Can Bad Spark Plugs Stop A Car While Running?

In a gasoline-powered automobile, the combustion is ignited by spark plugs. If the spark plugs are unable to ignite the engine, your vehicle may stop running.

After all, the gasoline compound won’t ignite with worn-out spark plugs. You may only get a little time to get your car to the nearest repair shop and get the plugs replaced.

Thinking about what to do with the old one? Read out the article “What to do with old spark plugs?’

How To Start Car Engine With Bad Spark Plug?

A bad spark plug can still start your car’s engine, but only if it is not cracked or broken. There are some basic tips that you should follow if you want to start your car with faulty spark plugs.

Create a gap in the spark plug

Spark plugs need to have their gaps adjusted so that electrons can flow freely from the combustion chamber. Misfires can occur in the engine if the gap is either too small or too wide, making it hard to start the vehicle.

Therefore, it is crucial to adjust the gap between them to maintain constant power production for the running engine. Check your vehicle’s manual to determine the correct gap for your spark plug’s electrodes.

Get rid of grease and carbon residue

Eventually, your car won’t start because of uneven electron transmission caused by grease and carbon residue developed on the spark plug electrodes. Oil and carbon accumulation can be caused by several factors, the most prevalent of which are dirty fuel filters and long periods of engine idle.

A solution to this is to first scrape the covered surface using a wire brush or sandpaper to remove any carbon dust. After cleaning with a car cleaner, the spark plug should be allowed to dry before being installed again.

Check the end of the spark plug wire

Check the spark plug wire’s end if your car won’t turn over. The end portion of the spark plug wire connects to a car’s ignition coil. If the wire to the spark plug is disconnected, the car won’t start.

Read Also: What Causes Spark Plug Electrode To Bend | The True Cause

Is It Safe To Drive A Car Without Spark Plugs?

Suppose the spark plug is broken or missing from a vehicle with a single cylinder. In that case, the petrol engine will still start and run normally. Without a spark plug, the car is unable to use the energy stored in fuel to generate heat.

Your car will still start, but the lack of a spark plug will cause the crank to be unsteady. Last but not least, if your car has a diesel engine, you won’t need a spark plug to get it going. That’s because spark plugs aren’t necessary for diesel engines.


Keep in mind that worn-out or faulty spark plugs could be the cause of your car’s inability to start. Even while it is possible to get around in a car with a bad spark plug, it is recommended that you replace it or get it fixed as soon as possible.

These little spark plugs do an incredible job of keeping your car or truck on the road. Therefore, it is essential that you preserve this automobile part in fine working order.

Enjoy your time behind the wheel while avoiding accidents!

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