# Harmonic balancer **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [December 10, 2007, 6:26pm UTC](https://community.cartalk.com/t/harmonic-balancer/8198 "2007-12-10T18:26:03Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![randoo](https://avatars.discourse-cdn.com/v4/letter/r/ebca7d/32.png) [@randoo](https://community.cartalk.com/u/randoo)\ **Post date:** [December 10, 2007, 6:26pm UTC](https://community.cartalk.com/t/harmonic-balancer/8198/1 "2007-12-10T18:26:03Z")
how can i diagnose a bad sensor in a harmonic balancer. what are the symptoms? ---
**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\ **Post date:** [December 10, 2007, 7:33pm UTC](https://community.cartalk.com/t/harmonic-balancer/8198/2 "2007-12-10T19:33:15Z")
Your harmonic balancer doesn’t have a sensor. It simply dampens rotational pulses in your crankshaft caused by the banging of the pistons. What’s the year, make, model, mileage, and history of your vehicle? What are the symptoms? What have you tried so far? Is there any other info such as something a shop said that would help? ---
**Author:** ![bing](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/bing/32/4619_2.png) [@bing](https://community.cartalk.com/u/bing)\ **Post date:** [December 10, 2007, 7:40pm UTC](https://community.cartalk.com/t/harmonic-balancer/8198/3 "2007-12-10T19:40:31Z")
The crank sensor takes readings off of the balancer to tell the computer where the crankshaft is. So if you’ve got a floppy balancer or bad sensor, the computer won’t know where the crank is. Result: Car dies, won’t start, or very least intermittant miss. ---
**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\ **Post date:** [December 10, 2007, 8:06pm UTC](https://community.cartalk.com/t/harmonic-balancer/8198/4 "2007-12-10T20:06:53Z")
Thanks Bing. I stand corrected. The crank position sensor never even occurred to me. ---
**Author:** ![DARTMAN69](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/dartman69/32/29_2.png) [@DARTMAN69](https://community.cartalk.com/u/DARTMAN69)\ **Post date:** [December 10, 2007, 8:49pm UTC](https://community.cartalk.com/t/harmonic-balancer/8198/5 "2007-12-10T20:49:29Z")
Not all crank sensors take readings off the harmonic balancer. In order to give you any tips we need to know what type of vehicle and what type of problems you are experiencing. ~Michael ---
**Author:** ![DanOzSTX](https://avatars.discourse-cdn.com/v4/letter/d/dfb087/32.png) [@DanOzSTX](https://community.cartalk.com/u/DanOzSTX)\ **Post date:** [December 10, 2007, 11:13pm UTC](https://community.cartalk.com/t/harmonic-balancer/8198/6 "2007-12-10T23:13:48Z")
It would help to know the details of this vehicle. Ive replaced to GM harmonuic balancers and I could tell as they got bad by the clanging noise along the serpentine belt. I was able to turn the belt easily to a certain point in either direction when I had bad ones. If it is you harmonic balancer and you are DIYing it, be sure to bring the old one into the store with you if possible. Both of the ones I replaced turned out to be the wrong unit in the Advance Auto computer. They are pretty specific and the first one I ended up having Advance buy me a new crank position sensor because of their wrong information in the computer. Plus they had to overnight the correct one to me ---
**Author:** ![karl-sieger](https://avatars.discourse-cdn.com/v4/letter/k/c77e96/32.png) [@karl-sieger](https://community.cartalk.com/u/karl-sieger)\ **Post date:** [December 11, 2007, 1:04am UTC](https://community.cartalk.com/t/harmonic-balancer/8198/7 "2007-12-11T01:04:11Z")
An OP should be required to give make, model, and year, at least. It’s so hard to give a precise answer W/O this info; unless, of course they’re asking a general automotive question which maybe this person is.