# Ho do I know if I have rod knock? **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** amanti, kia\ **Created:** [September 12, 2018, 10:07pm UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885 "2018-09-12T22:07:15Z")\ **Posts on this page:** 18\ **Page:** 1
**Author:** ![iag360\_141684](https://avatars.discourse-cdn.com/v4/letter/i/df705f/32.png) [@iag360\_141684](https://community.cartalk.com/u/iag360_141684)\ **Post date:** [September 12, 2018, 10:07pm UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/1 "2018-09-12T22:07:15Z")
Engine vibrates and knocks only at a certain rpm. Goes away when I lower that rpm or raise it higher.? ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [September 12, 2018, 10:17pm UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/2 "2018-09-12T22:17:20Z")
A rod knock occurs at all RPM’s Tester ---
**Author:** ![iag360\_141684](https://avatars.discourse-cdn.com/v4/letter/i/df705f/32.png) [@iag360\_141684](https://community.cartalk.com/u/iag360_141684)\ **Post date:** [September 12, 2018, 10:50pm UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/4 "2018-09-12T22:50:12Z")
Do you know what may cause a knocking noise at a certain rpm? I have bad motor mounts and supposedly bad control arm. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [September 12, 2018, 11:01pm UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/5 "2018-09-12T23:01:24Z")
If the vehicle has an automatic transmission, I’ve heard a cracked flex plate make a knocking noise at a certain RPM. ![](https://global.discourse-cdn.com/cartalk/original/2X/b/bf958f00410de4fd9655d24bdea6298612391c57.jpeg) Tester ---
**Author:** ![iag360\_141684](https://avatars.discourse-cdn.com/v4/letter/i/df705f/32.png) [@iag360\_141684](https://community.cartalk.com/u/iag360_141684)\ **Post date:** [September 12, 2018, 11:36pm UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/7 "2018-09-12T23:36:12Z")
Thank you. Is this severe or a safety concern? ---
**Author:** ![iag360\_141684](https://avatars.discourse-cdn.com/v4/letter/i/df705f/32.png) [@iag360\_141684](https://community.cartalk.com/u/iag360_141684)\ **Post date:** [September 12, 2018, 11:40pm UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/8 "2018-09-12T23:40:29Z")
Also it’s not a consistent sound. It sounds more of a creaking noise along with vibration and sometimes I can’t replicate it but it happens 30-40% of the time. It’s not a constant ticking if that helps ---
**Author:** ![Dean-in-Des-Moines](https://avatars.discourse-cdn.com/v4/letter/d/8e8cbc/32.png) [@Dean-in-Des-Moines](https://community.cartalk.com/u/Dean-in-Des-Moines)\ **Post date:** [September 13, 2018, 3:03am UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/9 "2018-09-13T03:03:37Z")
Would it be fair to ask what engine you are listening to? Not all engines have pushrods. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [September 13, 2018, 3:17am UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/10 "2018-09-13T03:17:47Z")
Once your reach that rpm, does the sound change when you then rapidly accelerate in gear? What if you shift into neutral and coast? Do you hear this sound if you increase the rpm to that same range when idling in the driveway? ---
**Author:** ![iag360\_141684](https://avatars.discourse-cdn.com/v4/letter/i/df705f/32.png) [@iag360\_141684](https://community.cartalk.com/u/iag360_141684)\ **Post date:** [September 13, 2018, 4:32am UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/11 "2018-09-13T04:32:15Z")
It’s a 3.5l 2004 kia amanti ---
**Author:** ![iag360\_141684](https://avatars.discourse-cdn.com/v4/letter/i/df705f/32.png) [@iag360\_141684](https://community.cartalk.com/u/iag360_141684)\ **Post date:** [September 13, 2018, 4:34am UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/12 "2018-09-13T04:34:13Z")
So when I reach the thumping RPM, as Soon as I speed up or slow down OR let go of the pedal, the sound goes away. As for idling, I sat in PARK and reach the RPM and I get no noise. So it only seems to be while in drive? ---
**Author:** ![iag360\_141684](https://avatars.discourse-cdn.com/v4/letter/i/df705f/32.png) [@iag360\_141684](https://community.cartalk.com/u/iag360_141684)\ **Post date:** [September 13, 2018, 4:35am UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/13 "2018-09-13T04:35:05Z")
The thumping/vibration only lasts 4 seconds maximum. And that’s probably because I cruise anyway. Always letting go of the pedal. ---
**Author:** ![iag360\_141684](https://avatars.discourse-cdn.com/v4/letter/i/df705f/32.png) [@iag360\_141684](https://community.cartalk.com/u/iag360_141684)\ **Post date:** [September 13, 2018, 4:37am UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/14 "2018-09-13T04:37:51Z")
i DO have bad motor mounts but THAT noise happens when I suddenly take off or break. ---
**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:** [September 13, 2018, 2:36pm UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/15 "2018-09-13T14:36:10Z")
Do you get the sound if you rev it while stationary in neutral/park? If so, have a helper rev it while you listen under the hood. ---
**Author:** ![iag360\_141684](https://avatars.discourse-cdn.com/v4/letter/i/df705f/32.png) [@iag360\_141684](https://community.cartalk.com/u/iag360_141684)\ **Post date:** [September 13, 2018, 5:07pm UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/16 "2018-09-13T17:07:00Z")
It does not ---
**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:** [September 13, 2018, 5:19pm UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/17 "2018-09-13T17:19:52Z")
I see now my question was redundant. I missed that. So it could be in the transaxle or driveshafts . ---
**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:** [September 13, 2018, 8:50pm UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/18 "2018-09-13T20:50:55Z")
> [@iag360\_141684](#): > > THAT noise happens when I suddenly take off or break. What did you break? Do you plan on replacing that broken part? 🤔 ---
**Author:** ![iag360\_141684](https://avatars.discourse-cdn.com/v4/letter/i/df705f/32.png) [@iag360\_141684](https://community.cartalk.com/u/iag360_141684)\ **Post date:** [September 13, 2018, 9:03pm UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/19 "2018-09-13T21:03:37Z")
Plan on replacing your English language for a new one my friend ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [September 14, 2018, 11:00am UTC](https://community.cartalk.com/t/ho-do-i-know-if-i-have-rod-knock/124885/20 "2018-09-14T11:00:27Z")
Could be the motor mounts. You know they’re bad, replace them.