916ludester

1994 Prelude Vtec

I get an odd sound when I'm in the 2500-3000 rpm range. Most notably from 2500-2800. No other range makes the noise. The noise will happen whether I'm driving or in neutral and just revving. The noise happens when accelerating, but can also be heard when decelerating. It has had this sound for a bit over a year now. When it first started I was told it was part of the exhaust. They cut a flange I believe it was called and the noise lowered. They told me to go to a muffler shop to get it fixed up. The sound came back after a while. Had another shop check it out recently and a piece of my muffler needed to be rewelded which they did. Sound came back within a mile if that. At that point I was thinking Ok, I'll just go piece together a custom exhaust and take care of an upgrade I wanted and get rid of the sound at the same time. My only thing is, the sounds seems to be coming from under the valve cover. It's loudest from the engine bay. Performance isn't affected, but I'm wondering if it could be something besides the exhaust? Checking online and forums, it seems it could be numerous things including timing related issues. Here's some vids in case anybody has heard this before.

boyasaurus

Sounds like two objects vibrating against each other. Check all exhaust connections, all the way back to see if its loose. Might be leaking air causing a worn out gasket to vibrate. You said it seems to be coming from under the valve cover. Reset your valve lash, check your distributor seal that is connect to the cam, tensioner area may be loose somewhere causing that noise. idk what im saying, just trying to be logical. could be anything. lol

916ludester

Just an update. Checked the headers since that's where the sound seemed to come from. The down pipe (a pipe) on the inside was cracked. Also was missing a bracket in the area. Had the pipe welded. Bracket was $18. Sound is finally gone. woot woot