5 Engine Misfire Symptoms, Causes and Solutions

Jerry Wilson
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What is an Engine Misfire?

Gasoline engine ignitions require that you press the gas pedal to bring the vehicle up to a speed of about 2,200 rpm. At this speed, the engine is able to create enough power to run smoothly and produce a smooth exhaust.

The engine misfire occurs when the engine cannot achieve that ideal speed for any reason.

There are several potential causes for this condition. These include bad spark plugs, problems with engine operation timing, or faulty fuel. You may also experience the misfire if the batteries have low starter power, if the fuel filter has clogs, or if the air filter is not working properly.

In most cases, an engine misfire occurs when one or more of the spark plugs do not operate properly. The spark plugs need to have the correct voltage to ignite the air and fuel mixture efficiently and produce a smooth idle.

From time to time, the sparks that the spark plugs generate may not reach the fuel. There are a number of reasons why this might happen. It can be caused by an engine timing or by a low battery power.

Is It Safe To Drive With A Misfiring Engine? Why You Should Care

Misfiring in an engine means that one or more cylinders are misfiring. If this occurs regularly, then it’s likely to be considered a serious problem, since it can have a serious effect on the car, and in many cases, be even dangerous.

A misfiring engine can cost you a lot of money, because it needs to be fixed, and if you plan to sell it, you’ll probably have a tougher sell. Worst case scenario, you may be left stranded on the side of the road.

Here’s how to recognize a misfiring engine, its causes, and what you can do to fix it.


Engine misfires generally mean that one or more of the cylinders are not getting the right amount of air and fuel mixture. The engine will usually run rough and the Check Engine light may activate. Even though your vehicle’s factory warranty may not cover it, a misfire of this type is a non-critical situation. Nevertheless, it should be corrected because a misfire can be the first indication of a wiring or engine problem that could lead to a more serious issue. Here are five common causes of a carburetor misfire:

Worn spark plugs

Replacing the spark plugs is one of the most common repair projects that most do-it-yourselfers can handle. The spark plugs are the first place to look for an engine misfire. Dirt, engine oil and other contaminants can cause the spark plugs to become fire blocked. Improperly gapped spark plugs or worn out spark plugs can also cause an engine misfire. Again, replacing spark plugs is a simple repair that should be done as soon as you notice a misfire.

Causes and Solutions

Engine misfires can be caused by numerous factors and solvable by an equally lengthy list of options. I’ll try to cover the common causes in this post. It is important to note that an engine misfire can be caused by factors from the engine itself to the fuel system. To determine the root cause it is important to follow the instructions outlined in this write-up.

As mentioned in the example below, be sure to check each of the following three areas:

  • Engine Mechanically
  • Fuel System
  • Engine Electrical

Although you may seem like you are running engine diagnostics, what you’re really doing is identifying if the misfires are mechanical, fuel or electrical in nature. To do a proper engine diagnostic follow these steps;

  • Make sure your engine is cold and the car is not running.
  • Disconnect the battery ground cable. (Note: This is important to avoid potential risk of electrical shock.)
  • Crack open the valve cover and make sure that there is a little bit of oil on the top center pad.
  • If you don’t have an oil leak, run your hands over the top and bottom of the pistons. Do they feel equal?
  • With the ignition turned on, you should feel the fuel pump run (this will be your clue that the fuel system is functioning).


The initial step is the same for any type of car problem “ check the fluids. Make sure you aren’t running low on antifreeze, oil, or transmission fluid. If you hear the engine spluttering, it’s likely there is a problem with the spark plugs or coil.

Always be aware of how hot a car is running. If you notice the underside of your hood is hot, stop driving immediately!

Cooling the engine down will help prevent further damage.

Another sign of an overheating engine is black, white or blue smoke coming from the exhaust. If you are experiencing this sign, find a place with a flat piece of concrete to park. The cooling concrete will prevent your engine from overheating and causing more damage.

Losing the timing belt on your engine can be dangerous. Always keep an eye on how long it’s been since you’ve replaced the belt because if it’s past the recommended time, the engine can seize.