# Thumping when accelerating

**URL:** <https://community.cartalk.com/t/thumping-when-accelerating/3727>\
**Category:** Maintenance/Repairs\
**Created:** [August 27, 2007, 1:51am UTC](https://community.cartalk.com/t/thumping-when-accelerating/3727 "2007-08-27T01:51:31Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![paul3cathy](https://avatars.discourse-cdn.com/v4/letter/p/edb3f5/32.png) [@paul3cathy](https://community.cartalk.com/u/paul3cathy)\
**Post date:** [August 27, 2007, 1:51am UTC](https://community.cartalk.com/t/thumping-when-accelerating/3727/1 "2007-08-27T01:51:31Z")

</div>

Our 1998 Subaru Forrester has a scary thumping in the accelerator when the engine is under a load. The greater the load (e.g., going up a steep hill), the greater the thumping. It is not noticeable when idling or coasting. The local mechanic (Pep Boys) ran an engine diagnosis and declared nothing wrong. Any suggestions are appreciated!