Q: Hello, when my car is in park or neutral it starts to accelerate on its own.

asked by on

Yesterday I noticed that when my car is in park or neutral, the car will start accelerating on its own. For example, when Im in park the needle that sits on 1 starts to climb to 2 and then back down to 1. I drove it back home and every time I would ease up on the gas, the engine seemed like it was going to fall apart. Is this the idle air control valve or is it a sensor?

My car has 191000 miles.
My car has an automatic transmission.

It could be caused by several different problems like the idle control valve, engine vacuum leak, intake air filter clogged or contaminated mass air sensor or a sensor failure or engine just needs maintenance. I would suggest having the vehicle engine computer tested for codes and any other problems by a mechanic like one from YourMechanic so a proper diagnosis and fault found that can then be quoted and fixed.

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. Hello, when my car is in park or neutral it starts to accelerate 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: PO402 Excessive gas recirculation code

Hi there - while a cracked exhaust tube of any sort is a problem that needs to be addressed, I don't think it's related to your P0402 code. P0402 indicates excess exhaust flow into the intake - probably caused the...

Q: Car not idling properly

Hi, thanks for writing in. I'd be happy to help. This is a common symptom on many cars when what is called a mass airflow sensor is not working properly. This is a unit that monitors air flow intake as...

Q: The car is leaking oil but no check engine light or overheating. But the oil burning off exhaust? What could be wrong?

Hi there. The most common cause of this type of oil leak is a valve cover gasket that has worn out. With nearly 20 years of operation on your Nissan Maxima, it's quite possible that the valve cover gasket has...

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...
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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...