# Fluctuating idle

**URL:** <https://community.cartalk.com/t/fluctuating-idle/38991>\
**Category:** Maintenance/Repairs\
**Tags:** chevrolet, trailblazer\
**Created:** [November 3, 2009, 4:04pm UTC](https://community.cartalk.com/t/fluctuating-idle/38991 "2009-11-03T16:04:30Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![leftfield](https://avatars.discourse-cdn.com/v4/letter/l/6a8cbe/32.png) [@leftfield](https://community.cartalk.com/u/leftfield)\
**Post date:** [November 3, 2009, 4:04pm UTC](https://community.cartalk.com/t/fluctuating-idle/38991/1 "2009-11-03T16:04:30Z")

</div>

My girlfriend has a 2002 Chevy Trail Blazer.During warmer weather-or after the car has been driven awhile-the idle seems to fluctuate up and down.What would cause this?

---

<div class="post-metadata">

**Author:** ![mcparadise](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mcparadise/32/32_2.png) [@mcparadise](https://community.cartalk.com/u/mcparadise)\
**Post date:** [November 3, 2009, 4:46pm UTC](https://community.cartalk.com/t/fluctuating-idle/38991/2 "2009-11-03T16:46:20Z")

</div>

A vacuum leak or a problem with the idle air control (IAC) system are two possibilities.