Q: Q: My car is accelerating on its own.

asked by on

Once I start my car it start to accelerate on its own , like if someone is pressing the gas , if I put it in drive the car starts picking up speed & its hard to brake . I feel like I'm steping on both at the same time .

My car has 140000 miles.
My car has an automatic transmission.

Inasmuch as you are writing in about uncommanded (aka, "unintended") acceleration, I can tell you the National Highway Traffic Safety Administration, one of the Federal agencies that tracks vehicle defects, would love to hear from you. You can file an on-line complaint at their website www.NHTSA.gov (go to https://www-odi.nhtsa.dot.gov/VehicleComplaint/ ) or call in the Complaint to the NHTSA Vehicle Safety Hotline (Toll-Free: 1-888-327-4236 / Hearing Impaired (TTY): 1-800-424-9153).

Engine speed is dependent on the amount and rate at which air and fuel are admitted by the engine control systems into the combustion chambers. Based on the NHTSA complaint database, and other sources, relative to your specific year, make and model, I would recommend testing your idle air control (IAC) valve as well as cruise control system. Both of these systems have been implicated in the type of symptom you are describing.

If the problem is not found in either system, since you are describing this as a non-intermittent problem, it should not be too hard to narrow it down just by looking sequentially at each and every other component that controls the "rate" at which air and fuel are admitted to the intake system. While this issue remains unresolved, obviously you have to exercise caution and just remember that, if faced with wildly uncontrolled acceleration, simply turn the ignition switch to the off (but NOT "locked") position and then place the car in neutral, while being mindful of your surroundings and adjacent traffic.

I recommend having a certified mechanic, such as one from YourMechanic, come to your location to determine why the car is accelerating without cause and replace the idle air control (IAC) valve or inspect the cruise control system.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Q: My car is accelerating on its own.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Transmission problem - 2010 Buick Lacrosse CXL

The Diagnostic Trouble Code P0989 can set due to the following causes: Defective transmission fluid pressure sensor; Malfunctioning electronic pressure control solenoid; Defective electrical components, such as wires, connectors, and fuses; Insufficient transmission fluid levels; Dirty transmission fluid; Blockages within...

Q: Q: Car not going into reverse

Hi. Shifting problems on modern automatic vehicles usually lead to a failing solenoid. If it's a manual, it's more likely a mechanical problem either in the linkage or internal trans parts. I suggest having a mechanic from YourMechanic inspect your...

Q: had to make a sudden stop and now car makes a clicking sound when step on brakes

Hi there. The clicking sound you hear when braking might be a worn suspension component and not related to the brakes. Sway bar links for example can make clicking sounds when the bushings are worn. If ball joints are worn,...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.