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.

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・Fair and transparent pricing

Get a quote

What others are asking

Q: When starting RPM of car starts going down and then engine stops.

It sounds like you may have a fuel supply problem in getting the proper amount of fuel to the fuel injectors which may be caused by a bad fuel pump or potentially faulty fuel injectors. This can happen when the...

Q: After sitting overnight, white smoke when car starts

If it isn't grayish or blueish, then its just steam and it's nothing to worry about. Even if it is grayish / bluish, thats a little bit of oil burning, which wouldn't be all that surprising for a 15 year...

Q: Car won't start

Hi there. It sounds like it could definitely be a fuel problem, but a bad battery could cause a variety of problems as well. Be sure to have the battery properly tested before moving on to anything else. The problem...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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...