Rep Power: 811

I replaced my replica header with a kamikaze top portion for ex, now there is a constant rattle noise around 2500 to 3500 rpms and I can smell gas coming from the header. What should I do? I had to use the old gasket which is ported larger than stock.

 
Rep Power: 372

hmmm, try getting a new gasket from honda. Or did you make sure you tightened everyting up(i am sure you did, but i would double check). Is it a loud constant rattle or does it just rattle when you rev your engine?

Injen

 
Rep Power: 811

well it only does it between those rpm ranges while driving. I can rev the engine and don't hear it. It just started after the header install so I know it's that. Everything is tight, the gasket needs to be ported bigger so prolly isn't sealing, but the rattle I don't know.

 
Rep Power: 372

I dont know man, i guess take it to a shop and have them look at it.

Injen

 
Rep Power: 320

dude thats how mine is too!! it only makes its noise when im driving, reving it wont do it.. i think im'a recheck how tight the bolts are? maybe they needed time to sit then re-tighten, thats my only guess.. but the noise it makes really sounds like the gasket is makin noise cause its a faint sound of thin metal rattling, or thats how it sounds to me, mine isnt exactally a rattle its just a vibration kinda noise... not really a metal on metal sound..

is that what you were trying to get me to hear? about the same thing I descrbied mine is doing?

 
Rep Power: 0

that used to happen to me too after a installed HP header and Hi-flow cat-back.....but I started to notice that so whatwas happening was that the springs that go between the header and the down pipe in my case the hi-flow cat weren't long enogh because its different and I had to get a new gasket you know that doughnut type....2 1/4 " ...and know I don't have that problem!

 
Rep Power: 0

Well actually the sound I was getting was exhaust leaking....I had a metal to metal in the back cuz I had to adjust heat shield that was bent....

 
Rep Power: 811

Um well I only hear the noise around 2800rpms and it goes away if I rev further or shift. Ya one of the top bolts was loose, but that didn't help when I tightened. I still smell gas and it's rattling all the time. Could it be something with the downpipe touching somewhere on the bottom? This sucks!

 
Rep Power: 0

But If you Still smell gas....that means there is a leak... check for that gasket between the header and the down pipe....sometimes that gasket moves when not its not tight enough...

 
Rep Power: 811

Where was yours rattling from? I felt around and everything seems tight and secure.

 
Rep Power: 0

between the header and the down pipe. the way the stock down pipe fit with the stock header its a lil bit different...

 
Rep Power: 0

actually the bottom part of the stock header its what is different...

 
Rep Power: 811

I'm guessing, but maybe the downpipe is closer to the car and rattling against it?

 
Rep Power: 0

maybe....but then where are you getting that gas smell from?

 
Rep Power: 348

make sure everything is tight
check all the clearences
get a new gasket from honda

 
Rep Power: 811

i'm not porting another gasket. It will prolly leak as well cause ports are big.

Everything is tight, the car feels good driving around, I'm really thinking the downpipe before the cat is rubbing the car. It does NOT make sound when cold. Only after the car warms up do I start hearing it. Would wrapping the pipe with thermotec heat wrap do the job?

 
Rep Power: 320

hmm im'a have to see if mine is close to anything.. maybe i should get some wrap too

 
Rep Power: 299

Gasket.

 
Rep Power: 299

Heres my theory "thermal expansion". i think you ported to much. you gotta remember that metal expands when it gets hot. Here the pic you showed me of your port job. Those cracks between the flange and the header pipes are probley leaking causing the rattle sound.



maybe not but look into it.

 
Rep Power: 811

do you think it could be the downpipe? I felt under there and I can barely fit one finger between the chassis and pipe. I think that's the rattle and it only does it once the car is warm and pipes expand. About the ports, I don't think that's a problem. The welds are still there from the outside. I didn't grind into the welds at all. So would wrapping the pipe help if that's the problem?

 
Rep Power: 299

i dont know looks like you "ported" the inside welds off

 
Rep Power: 811

Um no trust me on this. The way the header was designed, the tubes did not get ported at all, just the top part which had a 2mm lip all around. So actually when I first got it the top opening was smaller than the tubes. I just evened it out.

One problem is the old gasket was very thin around the edges. I might just have to port a new one again to fix it. Still don't know about the rattle. Everything is bolted on real tight.

 
Rep Power: 299

I trust the pics! That 2mm lip is called a weld.



and thats a EX oem manifold