Signs of a Bad Idle Air Control Valve

A bad idle air intake valve will cause a vehicle to stall.
A bad idle air intake valve will cause a vehicle to stall.

An idle air control valve, also called an IAC valve, is found in every vehicle and is located inside of the throttle body. When a car idles at a red light or while parked, the idle air control valve regulates the amount of air that circulates in the engine, which keeps the engine at a steady RPM and prevents rough idling. When an air control valve goes bad due to either carbon buildup or getting stuck, there are a few obvious symptoms.

  1. Low RPMs

    • A bad idle air control valve will prevent adequate air flow to the engine and will result in increasingly lower RPMs when idling. The number of RPMs, while idling, will vary a bit based on the individual vehicle but is generally considered low when below 800 RPM. The RPMs will increase to normal levels when the accelerator is pressed.

    Stalling

    • As the air control valve becomes increasingly clogged, the engine RPMs, while idling, will continue to drop until the vehicle stalls. This problem can usually be identified by applying the gas. When the vehicle is about to stall, pressing the accelerator will cause the RPMs to increase and will keep the car running. If the pedal is released, the RPMs will quickly drop, and the vehicle will stall. Sometimes, depending on how badly the idle air control valve is clogged, the vehicle may run correctly when the accelerator is pressed, but then sputter or stall when decelerating.

    Rough Idle

    • If the idle air control valve has gone bad and no longer regulates the flow of air into the engine, typically due to the IAC being stuck open, the vehicle will idle roughly. A rough idle is characterized by shaking, vibrating and shuddering while the car is on but not moving. A rough idle due to a bad intake air control valve will eventually result in stalling immediately after starting the vehicle.

    Weather Variations

    • A bad idle air control valve can cause a car to stall immediately after ignition in warm weather, but the vehicle will start properly when it is cold. When the accelerator is pressed, however, the car will stall. Likewise, if the temperature outside is warm enough, the car may start even though the idle air control valve is bad but will require the driver to immediately press the acceleration pedal to keep it from stalling.

Related Searches

References

  • Photo Credit the powerful engine image by kuhar from Fotolia.com

Comments

You May Also Like

Related Ads

Featured
Florida, Zephyrhills NorthSouth Carolina, LandrumGeorgia, RedanUtah, Brigham CityFlorida, Zephyrhills NorthGeorgia, ValdostaUtah, Stansbury ParkSouth Carolina, ClearwaterFlorida, Zephyrhills NorthIowa, MartensdaleIowa, DawsonIllinois, HartfordSouth Carolina, LandrumGeorgia, GayVirginia, AccomacIdaho, PrestonPennsylvania, WoodlynGeorgia, ClarkstonGeorgia, GaySouth Carolina, ClearwaterIllinois, FieldonFlorida, Zephyrhills NorthSouth Carolina, ClearwaterSouth Carolina, ClearwaterUtah, Stansbury ParkUtah, Little Cottonwood Creek ValleyPennsylvania, WoodlynUtah, Little Cottonwood Creek ValleyUtah, Stansbury ParkVirginia, AccomacSouth Carolina, ClearwaterVirginia, AccomacPennsylvania, WoodlynUtah, Little Cottonwood Creek ValleyUtah, Little Cottonwood Creek ValleyUtah, Little Cottonwood Creek ValleySouth Carolina, LandrumFlorida, Zephyrhills NorthPennsylvania, WoodlynIowa, BrandonIllinois, FieldonUtah, Brigham CityUtah, Stansbury ParkVirginia, AccomacIndiana, Winona LakeUtah, Little Cottonwood Creek ValleySouth Carolina, ClearwaterUtah, Stansbury ParkUtah, Brigham CityPennsylvania, WoodlynIndiana, EatonUtah, Little Cottonwood Creek ValleyGeorgia, GayUtah, Stansbury ParkGeorgia, ClarkstonTexas, Sterling CityPennsylvania, WoodlynTexas, Wake VillageSouth Carolina, ClearwaterUtah, Little Cottonwood Creek ValleyFlorida, Zephyrhills NorthGeorgia, GayIowa, Keomah VillageGeorgia, MabletonUtah, Stansbury ParkSouth Carolina, ClearwaterSouth Carolina, LandrumUtah, Brigham CityVirginia, AccomacSouth Carolina, LandrumKentucky, Mount VernonUtah, Little Cottonwood Creek ValleyUtah, Stansbury ParkUtah, Little Cottonwood Creek ValleyUtah, Stansbury ParkPennsylvania, WoodlynUtah, Little Cottonwood Creek ValleyGeorgia, GayUtah, Brigham CityUtah, Stansbury ParkGeorgia, RedanVirginia, AccomacUtah, Stansbury ParkTexas, Sterling CitySouth Carolina, ClearwaterIndiana, MuncieSouth Carolina, LandrumSouth Carolina, ClearwaterGeorgia, Gay
View Mobile Site