Rattle Noise?

I just installed my header and they had a hole in the weld, so I fixed it using some "Thermo-Seal" stuff. Well, I got this rattling noise from them somewhere, I pulled the heat shield off my Cat, thinking that this would fix it, but it does not. What else could it be? Anyone have any suggestions? It only happens between 2.5 and 3.2 thousand RPM's when car is in motion (does nopt make this noise when in neutral).

Thanks!

It might be the heat shield farther down your exhaust, did you check those? Mine had a screw loose once and made a horrible sound around that rpm.

I bet your cat is blown. Mine is making a rattle when I take off from a stop. I got underneith the car and I hit the cat and the rattle is comming from inside the cat. Get under the car and hit the cat.

I just installed a new cat about 3 months ago when I got my DC Catback. I put in a new CATCO High Flow cat, would this be blown already?

another thing to check... less intuitive... if you've got an automatic transmission, make sure you've got enough fluid in it.

That cant be the problem, I have a 5-Speed. It sounds like it is coming from the front somewhere. It is odd because it is only between the first stated RPM's, I dont know if it is something that needs to be fixed or if it is just an annoyance "nothing".

does it matter whether you're driving or not?

I am also having this exact same problem....I just got my exhaust installed and it is doing the exact same thing at the exact same rpms and only while moving.

Ok....while under the car checking to make sure all sheilds and such were tight....I noticed that the brace that holds the downpipe of the header was broken....this is the horseshoe looking bracket. I'm not sure if it is different on other types of Hondas. I took this to a friend and had it spot welded and it cleared up the rattle.

Yeah, it only makes this noise when I am driving.

Yeah I got kinda same prob. here too ..just installed an Apexi WS exhaust but I hear more of squeaking sound at about (3000 rpm). The exhuast is secure so.. any ideas???

Originally posted by thewoahna
Yeah, it only makes this noise when I am driving.

did you ever find out what it was??? same thing happened to me today.

could it be a rock or pebble in the cat shield? i had this problem once, an dtook off the shield and pebble fell out.

i wish it was that easy. i found that i has an exhasut leak between the cat and the backpipe. i fixed it, but still that rattle. its sounds like its coming from the front somewhere. what could cause a noise to occur only when in gear? i could rev it to redline in park/neutral and never hear anything. but as soon as i stick it in 1st and start going, it comes back.

I never did find out the problem on mine. I checked all the heat shields and I could not find anything that I think would cause a rattle noise. I have kinda just learned to live with mine, it has gotten a LITTLE better, but not a whole lot. I have heard from people on other forums say that sometimes with the Seramic header, the Ceramic coating on the inside will loosen and sometimes make a noise, but mine have been making a noise since day one, so I dont know if that is the problem or not. I probably should have just gone with Stainless Header.

oh well. thanks for the response anyways.
btw, i have ss headers, so i dont think the ceramic matters. did you ever get your straightpipe? i doubt its the reason, but someone said maybe its just engine noise since its breathing easier because of the headers and highflow cat.

I know exactly what it is, or should I say I saw, eerrrr give me a day and I will find it.... I have it somewhere around here!!

thanks wags.

btw i went to speed merchants, and a guy told me it could have been a bad gasket. so i went home and changed the gasket on both sides of the cat, but the noise stayed. so i hope you can help. if not i gotta take it somewhere and pay to have it looked at. which can cost alot since i have no idea what im looking for.
for now i just gotta turn the music up and ignore it.

Like I said let me search for it, but I had something that not only said what it was, but told how to fix the problem, it had step by step pics and everything... Its nothing major, just simply annoying... Its in your down pipe, the internal pipe needs to be welded or something. I have to work today, but I will find it hopefully before tonight.... Peace