Metal vibration noise

[Tofuboy]

Just wondering if anyone has the same problem, the noise started after I drove over a speedbum and hit my exhaust. You can hear the noise is coming right below the front seats area.

The noise will only happen when the engine is warmed up.
It happens between 2500-3000 RPM.
It will happen in gear or in neutral.
It will happen only when it is on the ground. (I tried to lift the car up on a lift several times after I drove it until it warmed up and start making noise, put as soon as it leaves the ground the noise is gone)

I know many of you will say it's the cat or the heat shield, but I have tried driving the car without the shield and tap the cat will a rubber hammer and there is no noise indicating the cat is damaged inside, but the noise still exists.

[civickiller]

its probably a heat shield that got knocked loose

[luti]

Is it one of the heat shields above the cat attached to the chassis?

[PilotMojo]

Holy crap

Yah that noise will drive you up the fu---ng wall.

I had that happen to me last summer. and i drove like that for a month+
It was the little "aluminum" cover on my cat. i put up on the racks, and tore taht piece of shit off.

End of that story.

it takes like 2 minutes.

[Gerbilo]

I had the same problem ever since i did some offroading haha

same RPM range and all,.. from what I can tell is that it is the heat shield,... if you get rid of that, just don't park in high grass

other than that, i dunno what it could be, axle pipe maybe?

[Tofuboy]

sorry guys, it's not the heat shield cause I tried driving the car without the heat shield and it still makes the noise.

[Gerbilo]

since you say it doesn't do anything on the lift maybe it's somthing to do with the suspension, although that wouldn't explain why it makes noise at an RPM range....

i havent a clue, i've seen this problem a few times and it's always the heat sheild.

[knorsk]

I have the same problem. I know what it is I just haven't fixed it yet cause i'm gonna have to get it reweilded. Ok so if you hit a bump and pushed your rear wishbone or whatever suspension you have and bent the pipes it might be rattling against the chasis. Also if you look at it when it's rattling you might be able to see where it is touching. Mine is in the rear. I know you are going to laugh but when I lowered my car we came across a problem...the exhaust is just a couple of hairwidths away from the rear suspension arm and when i'm idling on hills/angles or at certain RPM's it hits the arm and rattles.

[drift]

what kind of car?

there's heatshields all along the exhaust piping that's bolted to the chassis. a few may have gotten bent and are rubbing each other, or the exhaust piping.

[Tofuboy]

It's a 95 civic EX MT, I check all the heat shields along the piping and they are not bent and there are no "witness marks". The sound is coming from right below the front seats.

I have taken out the cat and look into it, there seems to be no damage at all and no noise when I shake it.