Today, I was driving on the highway and when i slowed down for an exit all of a sudden my engine started making weird noise between 3000-4000rpm (also a quiet one around 2500 rpm).

When I'm in any other rpm it doesn't make that sound but when it's between the rpms i've mentioned above, it makes a noise. The noise kinda sounds like some metallic thing is rolling around or.. shaking... I tried to locate where the noise is coming from with my hood up but I couldn't really tell.

Does anyone know what's causing this problem and how to fix it?

Thanks.

btw it's 99 civic si

 

Check your heatshields on the exhaust and cat. I had a loud grinding/rattling noise that would only happen as you were at 3k rpms. It was a loose heatshield

 

i have the same problem, like a bearing rolling around in a can or something. thats wut i hear in my engine. i hear it most in second gear and the sound increases when im accelerating, gets loud at 3-4 k aswell. and it cant be a heatshield cuz i dont have one.. lol i just have headers exposed... i gotta b16a with 12:1 compression.. different internals.. and i bought it like that.. and sometimes in the morning when i goto school i dont really have time to warm it up soo i just start sit for maybe a min or less then leave.. sometimes my idle will go up and down... but im not harsh on the engine in the morning.. any help would be great and hopfuly itl answer his problem aswell as they seem to be the same.

thanx and im sorry if i stole the thread? but we seem to have similar problems..

 

ohh and it only sounds when im in a gear. or thats wut im thinkin cuz when im in in neutral and rev it it doesnt make the clinging sound.. its soo strange... and i dont like it. when i first got the car it wasnt like that.. there was a lil sound but my friend just said its my compression since its soo high i cant drive under 2500 rpm or itll make a lil sound.. and that is notthing compared to this.. arg

 

ttt, i letta mechanic check it out. but he doesnt specialize in hondas.. but he said its in the engine and not the trans or anything. anyone have any idea? not valve either... its really annoying

 

Thanks. It was the lose heat shield.