# Engine rev'ing in park

**URL:** <https://community.cartalk.com/t/engine-reving-in-park/40733>\
**Category:** Maintenance/Repairs\
**Tags:** focus, ford\
**Created:** [December 13, 2009, 9:54pm UTC](https://community.cartalk.com/t/engine-reving-in-park/40733 "2009-12-13T21:54:13Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Euphoria29](https://avatars.discourse-cdn.com/v4/letter/e/e47c2d/32.png) [@Euphoria29](https://community.cartalk.com/u/Euphoria29)\
**Post date:** [December 13, 2009, 9:54pm UTC](https://community.cartalk.com/t/engine-reving-in-park/40733/1 "2009-12-13T21:54:13Z")

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I have a 2002 ford focus. The past week when I put my car in park to idle, lets say at an atm or to turn off the car, it starts revving up. I made sure I wasn’t touching the accelerator. I made an appointment to get it looked at, but is this serious. It doesn’t happen every time but at least once every 2 days. thank you for any advice 🙂

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**Author:** ![cigroller](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@cigroller](https://community.cartalk.com/u/cigroller)\
**Post date:** [December 14, 2009, 1:46am UTC](https://community.cartalk.com/t/engine-reving-in-park/40733/2 "2009-12-14T01:46:29Z")

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What happens when the car is still in gear but you are sitting still - such as when you leave the car in drive while sitting at a traffic light or something? Is it generally idling higher than normal? Does the idle surge and fall at all? Is the check engine light on?

I think that the first likely culprits would be a sticking idle air control valve, a dirty throttle body, or a vacuum leak. Clarification on the above might help though.

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**Author:** ![Roadrunner](https://avatars.discourse-cdn.com/v4/letter/r/d2c977/32.png) [@Roadrunner](https://community.cartalk.com/u/Roadrunner)\
**Post date:** [December 14, 2009, 2:19am UTC](https://community.cartalk.com/t/engine-reving-in-park/40733/3 "2009-12-14T02:19:19Z")

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I’m going to suggest the fault MAY be due to a loose or broken throttle position sensor (TPS).

A broken or loose TPS can cause intermittent bursts of fuel from the injectors and a unstable idle because the PCM ‘thinks’ the throttle is moving.

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**Author:** ![Euphoria29](https://avatars.discourse-cdn.com/v4/letter/e/e47c2d/32.png) [@Euphoria29](https://community.cartalk.com/u/Euphoria29)\
**Post date:** [December 14, 2009, 12:05pm UTC](https://community.cartalk.com/t/engine-reving-in-park/40733/4 "2009-12-14T12:05:12Z")

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When the car is in drive and I am idling it sounds normal, it only happens when I put the car in park that it starts racing. No check engine light either which is why I am confused.