Q:

What is an engine misfire?

A:

Quick Answer

An engine misfire occurs when one or more of the cylinders inside the engine doesn't fire correctly. It is caused by an interruption of the air-to-fuel ratio inside the combustion chamber in the cylinder.

Continue Reading
What is an engine misfire?
Credit: Getty Images Europe Getty Images News Getty Images

Full Answer

An engine misfire causes the power to drop and reduces gas mileage. It also increases the vehicle's emissions and can cause it to fail an emissions test. A severe misfire can cause the driver to feel a jerking action while driving. Misfires can happen constantly or intermittently. Misfires can be grouped into three categories: fuel, ignition and engine mechanical. Common causes are an issue with the spark plugs, plug wires, the coils or the fuel-delivery system. A scanner can be used to determine which cylinder is misfiring.

The most effective way to prevent engine misfires is to follow the maintenance schedule outlined in the car's owners manual. The cost to repair an engine that is misfiring varies based on the cause of the misfire. Issues with the spark plugs cost about $100 to $300 to repair. Bad fuel delivery or a vacuum leak can cost between $100 to $1000. A mechanical breakdown, such as a burnt valve or a blown cylinder head gasket, varies significantly and can cost up to $10,000.

Learn more about Car Parts & Maintenance

Related Questions

  • Q:

    What is the purpose of a crankshaft sensor?

    A:

    A crankshaft sensor has two purposes: to help a vehicle's ignition system produce a spark and to signal the fuel system to inject gasoline into the engine's cylinders. Without the crankshaft sensor, the engine cannot continue to run.

    Full Answer >
  • Q:

    How does a starter work?

    A:

    A car's starter motor is an electric motor that engages and turns the main crankshaft, drawing air and fuel into the cylinders so the engine can start. To do this, the starter draws heavy current through the battery, engages a flywheel or flexplate connected to the crankshaft, and turns it.

    Full Answer >
  • Q:

    How does a W12 engine work?

    A:

    A W12 engine uses an engine configuration of either four rows of three cylinders or three banks of four cylinders that operate in an offset configuration to generate power. Some W12 engines are also set with a compact and fuel-efficient valve placement that covers the combustion chambers of the engine. The W12 engine typically operates with two exhaust engines, as it is made by merging two V6 engines together.

    Full Answer >
  • Q:

    How does a dual exhaust system improve your car?

    A:

    A true dual-exhaust system helps to improve the performance of a V-6 or V-8 engine by splitting the exhaust from the two banks of cylinders. However, it is less effective on smaller vehicles that use an inline four-cylinder engine. The system reduces the pressure to expel the exhaust fumes, allowing the engine to send more energy to the transmission.

    Full Answer >

Explore