# Engine knock/tap **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** outback, subaru\ **Created:** [July 6, 2009, 11:43pm UTC](https://community.cartalk.com/t/engine-knock-tap/32986 "2009-07-06T23:43:00Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![sacarius](https://avatars.discourse-cdn.com/v4/letter/s/e0b2c6/32.png) [@sacarius](https://community.cartalk.com/u/sacarius)\ **Post date:** [July 6, 2009, 11:43pm UTC](https://community.cartalk.com/t/engine-knock-tap/32986/1 "2009-07-06T23:43:00Z")
Hi, I have an '05 Subaru Outback, 40K miles, auto transmission. When the engine is warm, I hear a tapping/knocking nose when car is in gear, but idle. I’ve taken it to a couple mechanics, and unfortunately the car hasn’t performed for them so no one knows what’s going on. Anyone have any ideas? ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [July 7, 2009, 12:39am UTC](https://community.cartalk.com/t/engine-knock-tap/32986/2 "2009-07-07T00:39:09Z")
Maybe loose bolts or a crack in the flex plate. Checking means seperating the engine and trans. I would wait until it gets worse and steady. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [July 7, 2009, 1:38am UTC](https://community.cartalk.com/t/engine-knock-tap/32986/3 "2009-07-07T01:38:43Z")
Where is the noise coming from? Is the frequency of the noise in synch with engine speed (if you race the engine, does it tap faster?), or is it a constant rhythym, or is it more random? If the noise is a random one coming from underneath the car, it is likely just uneven expansion of some of the components in the exhaust system.