# Rough idle when put in park?

**URL:** <https://community.cartalk.com/t/rough-idle-when-put-in-park/7482>\
**Category:** Maintenance/Repairs\
**Tags:** explorer, parkingbrakes\
**Created:** [November 20, 2007, 7:41am UTC](https://community.cartalk.com/t/rough-idle-when-put-in-park/7482 "2007-11-20T07:41:42Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![spaceboy](https://avatars.discourse-cdn.com/v4/letter/s/3da27b/32.png) [@spaceboy](https://community.cartalk.com/u/spaceboy)\
**Post date:** [November 20, 2007, 7:41am UTC](https://community.cartalk.com/t/rough-idle-when-put-in-park/7482/1 "2007-11-20T07:41:42Z")

</div>

I have a 2001 Ford Explorer sport. Recently, when the vehicle is warmed up and you put it into park, the idle drops and gets rough. Occasionally the vehicle does die. It does not appear to do this when the car is cold though. I think I had something similar to this years ago when it was still under warranty and I think they said it was the PCV valve. Does this make sense?

---

<div class="post-metadata">

**Author:** ![Roadrunner](https://avatars.discourse-cdn.com/v4/letter/r/d2c977/32.png) [@Roadrunner](https://community.cartalk.com/u/Roadrunner)\
**Post date:** [November 21, 2007, 4:34am UTC](https://community.cartalk.com/t/rough-idle-when-put-in-park/7482/2 "2007-11-21T04:34:08Z")

</div>

The PCV valve is about the most simple component on an engine to check.

Pull it out from the valve cover and shake it. If it rattles, it’s good.

Another test is (with the engine at idle) to put you thumb over the end of the valve and see if there is air suction. If there is, it’s good.

You MAY have a faulty IAC motor or a dirty throttle body.

---

<div class="post-metadata">

**Author:** ![spaceboy](https://avatars.discourse-cdn.com/v4/letter/s/3da27b/32.png) [@spaceboy](https://community.cartalk.com/u/spaceboy)\
**Post date:** [November 21, 2007, 3:24pm UTC](https://community.cartalk.com/t/rough-idle-when-put-in-park/7482/3 "2007-11-21T15:24:54Z")

</div>

I’ll check it out.

---

<div class="post-metadata">

**Author:** ![Skypilot](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/skypilot/32/237_2.png) [@Skypilot](https://community.cartalk.com/u/Skypilot)\
**Post date:** [November 22, 2007, 12:19am UTC](https://community.cartalk.com/t/rough-idle-when-put-in-park/7482/4 "2007-11-22T00:19:46Z")

</div>

Sounds to me like it may be your IAC Valve.
