Car revving up on its on

[VesperSparrow]

Sometimes when I stop at a light or stopsign (leaving it in drive) or put the car in park while its running, its like the engine just revs up on its on...I wish I could produce the noise for ya but the best I can do is that it goes brmmm brmmm brmmm until I get going again...the RPM needle goes up and down...its like I'm giving it gas when I'm not...

any ideas???

I swear I'm gonna get a Vespa...

 

[Hardpan]

If it is fuel injected, I would suspect the idle control valve.

 

[JeanCat]

have the sensors on the transmission checked. we had a car do something similar. the engine would rev and the rpm meter almost peg out. scared the life out of me. turned out to be a sensor that thought the car was going faster than it was...it would do this even when stopped, similar to your experience.

 

[VesperSparrow]

thank you because all I could think about is the time the accelerator stuck in my mom's car...and my dad almost drowned in the river because the car went where the hell it wanted to went...