Skip the auto shop - Our mechanics make house calls

Q: Car accelerating while in park, shifts slowly.

asked by on

My car takes too long to shift gears. When in park, the car accelerates by itself.

A: The most likely issue here would be a fault...

The most likely issue here would be a faulty idle air control valve. This can cause the RPMs to rise when the transmission is in park and the engine is just idling. When the engine is not running correctly, the transmission will act differently than it normally would as well. This is sort of a cause and effect deal. I would recommend having your IAC inspected by a professional to determine if it is faulty. If so, have it replaced and see if your transmission reacts differently. If not, check the fluid level. If the fluid level is low, the transmission will also react differently.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: When I turn on my AC, it makes a weird noise?

There is a component inside the HVAC ductwork in your Mazda (middle of the dashboard more or less) called the expansion valve which regulates the transition of liquid Freon in your AC system to a gaseous state. This what produces...

Q: When accelerate, car hesitates and jerks

It's hard to say the shop is wrong when they have been able to visually inspect the car while I have not. If you do not trust the shop's diagnosis, it cannot hurt to get another mechanic to take a...

Q: Multiple problems with recently purchases used car

Hello. If the window on the passenger side only works with the driver switch and not the switch on the door, then the switch itself will more than likely need to be replaced. I usually test the circuit first before...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
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.