nikesb4dub

Hey Honda-Tech..
I just got this new problem with my car..its annoying and kinda embarrasing lol. I get this strange vibration when coming off gas at low rpm. It sounds like some metal is vibrating underneath the car.

Background about my car: 96 gs-r, 109k, stock except for greddy se cb and dc header. car is healthy and never had this problem until a week ago.

There really isn't much to explain about the vibration.. it happens at the same rpm everytime when decelerating.. It doesn't happen in the morning when it is cold and higher idle but once its warmed up the noise is very noticable. I already did the obvious and had someone give gas and let go while I was underneath the car incase it was obviously noticable where it was coming from.

I decided to post a video because I realized it would be hard to determine otherwise...
Someone point me in the right direction to fixing this annoying noise!!

embedded code didnt work so heres a direct link to the video.. http://yfrog.com/j2wwyz

wastedyouth2542

sounds like your exhaust is vibrating on something

vtaker

Did you hear the noise at all when you were underneath the car?

Check around the rear suspension. If you had the car on jack stands, the suspension was probably fully extended, thus giving the exhaust more clearance.

Stock integras have a similar problem with the downpipe, but if you have a full dc setup then that wouldn't be it.

8YourV8

I recommend checking your clearances, heat shields, and muffler.

If none of those solve your problem, your throwout bearing could be too loose causing certain RPM ranges to trigger the metal against metal rattling noise associated with a worn/abused/loose throwout bearing.

nikesb4dub

Ok so I took it to the exhaust shop that I got it installed 3 months ago. He said that it isn't rattling/vibrating in the back..he said the noise is coming from around the area of the cat..
He said it could be the heat shields causing the vibration..
Or he said it could be internal and "the start of my cat going bad"

He said the only way to tell would be to put it on the lift and check...
I asked him if he could check it out and he said to bring it by tomorrow morning.
What u guys think? I hope its not the cat..

Also u think its a free check since he installed it? Or I should clarify if its free check before he lifts it? Money kinda tight right now :/

nikesb4dub

Yeah I already had vibration problem lol. That's why I got a header in the first place.

vtaker

It should be free.

wastedyouth2542

its probably the heat shield thats on top of the cat, just take it off.

nikesb4dub

Hopefully, thanks man

Fasho. That makes me feel better, I was hoping it wasn't the cat...guess well see after 10 lol. So exactly what does the heat shield do if I can just take it off..don't U need it? Lol.. still slowly learning..

nikesb4dub

So...I know not that many ppl replied cuz its hard to say what it is im guessing...but...

I went to the exhaust shop yesterday and spent 2 hours there's with no resolution...first they just lifted my car..wiggled the exhaust around and I guess tightened the heat sheilds..
First they tried to send me on my way and say it went away..

I drive once block away and its still loud as ever..
I go back and they lift it again and use a stethoscope and said they hear the noise more in the header area than that cat! (Header is dc 421 which was purchased brand new less than 13 months ago and was professionally installed. Never had any issues with it)
Basically they left me with they have no idea what's causing it but said its probably the core of my cat going bad and if it is that it should get worse within the next 500 miles

Do people agree with their diagnosis? Should I go somewhere else? The noise makes me really not even wanna drive it because my car sounds all mean then sounds like junk when pulling up at stopsigns/lights lol...

If it was the cat wouldn't I get a code? And why does the noise only happen when engine is warm?

Any input is appreciated.

vtaker

I know what a broken cat sounds like. I bottomed out in a driveway once and it broke my cat. Above 4k rpms it sounded like a heavy metal on metal clacking noise. I thought my clutch was gone, but it was my cat. From the video you posted, this doesn't seem likely.

Make a video of you driving it around. Maybe that will help. Otherwise it could very well be the heatshield on cat NOT the ones attached to the car. See if the shop will tack weld the seams on your cat heatshield.

nikesb4dub

Thanks a lot for the help vtaker. Im gonna try to make another video driving soon, its pretty much the same sound though . Pretty busy with finals right now though :/

Lol tell me why the guy tried to brush it off like im making a big deal about the noise..he said most people wouldn't notice it...im thinkin maybe if your deaf ...ahaha

nikesb4dub

Also the reason why they said they didn't think it was the shields is because the noise didn't sound "tinny" if that makes any sense

vtaker

I still think it could be a clearance issue where the axle back curves over the rear suspension. Otherwise you might need to swap our your stock parts one by one to eliminate possible causes.

What kind of hoist do they have?

This one:


Or this one:

94 ls-r

My 99 4 door does the same thing when cold. Its the exhaust. The old owner put a greddy cat back on it.

nikesb4dub

Yeah I was also thinking about going back to stock too. Kinda sucks since I can't do it myself but id rather have stock exhaust then this noise...

They had both of them actually but they put my car on the second image you posted

nikesb4dub

Really? So what does that mean? I bought the exhaust brand new 3 months ago..

94 ls-r

I havent crawled under it yet. Just got the car and only does when cold. Its annoying as hell. I dont really like the exhaust so gonna have it done like my 2 door when get some cash. The reason the exhaust shop cant find it is cause they probably just shakin it by hand. Some one needs to rev it while it lifted up

nikesb4dub

Funny mine the opposite. Only when warm. I wouldnt mind as much when cold because atleast it would go away lol.
They had 2 guys working on it..one guy was revving it while it was up there and another dude underneath trying to listen..