# Honda Civic and engine rattle **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [September 4, 2011, 6:34pm UTC](https://community.cartalk.com/t/honda-civic-and-engine-rattle/67646 "2011-09-04T18:34:54Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![sleepeasy407](https://avatars.discourse-cdn.com/v4/letter/s/ecd19e/32.png) [@sleepeasy407](https://community.cartalk.com/u/sleepeasy407)\ **Post date:** [September 4, 2011, 6:34pm UTC](https://community.cartalk.com/t/honda-civic-and-engine-rattle/67646/1 "2011-09-04T18:34:54Z")
I have a 2000 Honda Civic, manual transmission with 91,000 miles. I have a rattle coming from the engine, that was there before and after the timing belt was changed. I just notice it more now after the timing belt was changed. The rattle sounds like a marble or nut in a metal container(cylinder?). I don’t hear it with just revving the engine, only when the car is in gear…put a load on the engine. It increases in speed as the engine speed increases and is harder to hear or it disappears as the load on the engine decreases. It is NOT tin-y like a a heat sheild. Could this have something to do with the pistons in the engine, the motor mounts, or something else? Also, what kind of costs as I looking at? Thanks ---
**Author:** ![keith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/keith/32/5518_2.png) [@keith](https://community.cartalk.com/u/keith)\ **Post date:** [September 4, 2011, 7:05pm UTC](https://community.cartalk.com/t/honda-civic-and-engine-rattle/67646/2 "2011-09-04T19:05:07Z")
Sounds like engine knock. You probably have a defective knock sensor. Is the check engine light on? ---
**Author:** ![keith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/keith/32/5518_2.png) [@keith](https://community.cartalk.com/u/keith)\ **Post date:** [September 4, 2011, 7:12pm UTC](https://community.cartalk.com/t/honda-civic-and-engine-rattle/67646/3 "2011-09-04T19:12:57Z")
A little more background on engine knock. It comes from either too much compression or ignition timing too advanced. Modern engines use the computer to control the ignition timing. One of the inputs is from a device called a knock sensor, basically a glorified microphone. The computer advances the timing within the rest of the parameters given to it as far as it can. When knocking starts, the knock sensor sends a signal to the computer to back off the timing a bit. The optimum timing for engine efficiency is just before it begins to knock. The knock sensor is important to maintain optimum timing. The knock will eventually cause other damage to the engine. ---
**Author:** ![sleepeasy407](https://avatars.discourse-cdn.com/v4/letter/s/ecd19e/32.png) [@sleepeasy407](https://community.cartalk.com/u/sleepeasy407)\ **Post date:** [September 4, 2011, 7:33pm UTC](https://community.cartalk.com/t/honda-civic-and-engine-rattle/67646/4 "2011-09-04T19:33:17Z")
No lights to indicate a problem with the engine and I’m pretty/very good as far as maintenance is concerned. Should I just have this sensor checked? ---
**Author:** ![keith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/keith/32/5518_2.png) [@keith](https://community.cartalk.com/u/keith)\ **Post date:** [September 4, 2011, 8:06pm UTC](https://community.cartalk.com/t/honda-civic-and-engine-rattle/67646/5 "2011-09-04T20:06:44Z")
Yes, any good mechanic can recognize the sound instantly. Don’t tell them in advance, just let them drive the car and see if they don’t conclude that its the knock sensor immediately. BTW, for being a glorified microphone, they can get kinda pricy. ---
**Author:** ![sleepeasy407](https://avatars.discourse-cdn.com/v4/letter/s/ecd19e/32.png) [@sleepeasy407](https://community.cartalk.com/u/sleepeasy407)\ **Post date:** [September 4, 2011, 9:15pm UTC](https://community.cartalk.com/t/honda-civic-and-engine-rattle/67646/6 "2011-09-04T21:15:38Z")
Thanks, I’ll give it a try.