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Q: Car accelerated on its own, increasing RPMs & speed

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While I was driving this morning, around 25 mph, my car started accelerating on it’s own. This caused the engine RPMs to increase and naturally so did the speed. This has happened several times; not constantly but intermittently. Could you give me your diagnosis and is this something I could fix myself?

Hello. There are a few possible causes of this but most of the time it is caused by a failing throttle body. If the throttle plate sticks and does not return to the correct position then the vehicle will accelerate.

In some cases it can also be caused by the floor mats in the vehicle. If the pedal gets stuck on it, but that is not as common. I usually check the throttle body and see if it is sticking and clean the throttle body if it is dirty. If that does not solve it then I would go ahead and replace the throttle body. If you need to have this looked at, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose and repair this as necessary.

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