Q:

Why does my car idle high in park?

A:

Quick Answer

Possible causes of a car idling high while in park include the car having a bad accelerator, an overheating engine, the fuel pressure regulator operating at low pressure and the alternator acting up. One symptom of the car's idling problem is the driver having to apply brakes intensely when parked.

Know More
Why does my car idle high in park?
Credit: Amos Chapple Lonely Planet Images Getty Images

Full Answer

Each of these possible causes has an easy solution. The accelerator and alternator can be replaced if they are diagnosed as malfunctioning. The overheating engine can be repaired, though a certified mechanic will need to check the cooling system. The fuel pressure regulator can be examined with a fuel pressure gauge and replaced by a mechanic as needed.

Learn more about Car Parts & Maintenance

Related Questions

  • Q:

    What causes high idle problems?

    A:

    The number one cause for high idle is an imbalance in air pressure. An engine that is idling too high may be caused by a faulty idle air control motor valve that has completely failed or that has simply become weak and is not functioning correctly.

    Full Answer >
  • Q:

    Why does a car misfire when in idle?

    A:

    There are a number of reasons why an engine might misfire while it is idling. Usually misfires occur when there is no spark, the air/fuel mixture is out of balance or the engine is losing compression.

    Full Answer >
  • Q:

    What is happening when a car vibrates at idle?

    A:

    A car or car's engine may vibrate while idling for various reasons, including that the motor or transmission mounts have a problem. When a car is stopped at a red light or turned on in park, a noticeable vibration may occur that signals damaged or broken transmission mounts.

    Full Answer >
  • Q:

    Why does my car idle high?

    A:

    There are many reasons a car idles fast, but one common reason is a vacuum leak. Older muscle cars have only two or three vacuum hoses, making finding the leak easy. Newer vehicles have complex vacuum systems to reduce emissions, so leaks are more difficult to find. Popular Mechanics suggests spraying carburetor cleaner on a suspected leak and listening for the engine speed to increase.

    Full Answer >
    Filed Under:

Explore