rattle, car's cold, exhaust?
 

everytime i start my car up in the morning, there is a rattle.. it sounded like it was coming from my serpentine belt, but i think its something to do with the exhaust system.. my car has 112,000 miles on it, 02 civic lx.
it rattles when the car is idle, and also when i accelerate
had a couple friends look at it, they said it might be the sensor inside the cat back? it might have fell off inside and rattling inside the exhaust...

is there anything i can look at, pull out or what? when the car is at normal temperature, i cant hear much of anything
any help is appreciated

Check the heatshield around your catalytic converter. It's not uncommon for those to break free over time, due to rust and vibration.

Re: (toyomatt84)
 

the heat shield is held on by a couple bolts right? can i just remove it simply by taking the bolts off?

Re: (hondalove323)
 

If they're not COMPLETELY corroded, sure. But, unless that catalytic converter is relatively new, I would doubt that they'd come off in one piece.

Re: (toyomatt84)
 

my car has 112,000 miles on it.... so its not really new

is the heat shield ever necessary to be on there?

it serves a purpose, thats why its on the car. its there to keep heat away from the intake and rest of engine bay. if i could modd my old shield to put it over my HP header, i would, so cops wont be able to see it.

Re: (01_civic)
 

yeah.... so then why dont aftermarket headers have this heat shield on??
and i know its there to keep the heat away

The top one that is sandwiched between the cat and the floorpan, I would keep that one in tact.

The bottom one isn't hugely important. You do run some degree of risk of flash cooling by having the hot cat hit a puddle of water or something. I run my cat without shields.

Oh, and don't drive through a cornfield either.

This is odd. I have a 02 lx just like u with 112000 miles on it as well (how ironic). Well i have started to notice a huge rattle in mine. When it's idleing the rear bumper vibrates real bad when it's cold. When i tap the gas it stops. Anyone have any other ideas.

yeah.. it seems to be getting worse, and i dont think its the heat shield..

yea I noticed I have an occasional rattle after I stop at a stop light and idle for a second it rattles shortly, almost like the rpms dropped below their normal threshold. Any ideas? It seems to be off and on

Jack your car up and check all the heat shields, check and see if the exhaust is hitting other parts of the body or suspension.

Have a peek.

my exhaust rattles on the rear bumper when its idle in cold weather also. after the cars goin and warmed up, it goes away though.

could also be bad engine mounts

I also notice that most hondas, when they idle the tailpipe vibrates crazy. check all the rubber exhaust mounts and that no section of the exhaust is touching the underbelly

how would u know if its the engine mounts? my car has a rattle sound comin from the hood. but when i press down on the hood just a bit it goes away. it also goes away after drivin it for a bit. motor mounts? how do i check the motor mounts if theyre ok?

take a crowbar and jam it between in the engine mount and see if you can move it. if it moves its bad

To me for the heat shield, all it is is metal. I think that Exhaust wrap stuff is 10x better then a silly metal heat shield Im turboed and I didn't use a head shield or exhaust wrap and talk about hot, Scolded my hand pretty bad haha

the heatshield is pretty sturdy. It can rattle but more likley the hood is just a bit lose and that rattles.

run you car, press on the hood see if that does anything. open the hood, take a bat or broom handle and press against the heatshield see if that helps, same with the cat.

Similar Problem
 

I think im having a similar problem as the first poster:

2005 Civic 4dr
99,030 miles.

There is a subtle tin-can rattle sound while we are slowing down to a turn or a stoplight. The sound goes away for the most part when we stop, or are driving at normal speed (maybe we just cant hear it because of road noise).

The sound seems to come from the front driver-side engine area.

To describe the sound I would say its like a few light nuts or bolts shaking around inside a tin-can, but not super loud or pronounced. its very subtle.

If it is the heat shields, does anyone know how much it would be to replace/fix at a dealership?

Thanks!

i had this exact problem, check all your nuts and bolts to make sure everyhing is on 100 percent pefect, make sure your intake gasket, the rubber that goes from the intake manifold to the throttle body is put on correctly or youl hear like a fluttering sound. also especialy check the bolts that go from the bottom of your header to your exhaust, make sure those are on really good and everything is even. mine would come loose every once in a while so id have to retigten and retighten then after tightening the rattle would go away, also if your exhaust hits in the rear bumber thats normal i guess, take it to a muffler shop and have then see what they can do, or maybe have them weld your exhaust and hang lower, insted of having it put on with rubbers, thats why it moves so much.. or maybe you have somethign stuck in the exhaust making air harder to get through thus the exes ratteling hope i helped

Re: rattle, car's cold, exhaust?
 

is there suposed to be a gasket between the header/downpipe and cat?

Re: rattle, car's cold, exhaust?
 

I have the same issue occasionally. Do you have a front strut tower brace? I haven't been able to determine if that's the source of the noise. It's minor enough that it doesn't significantly bother me, just interested in a follow-up.

Re: rattle, car's cold, exhaust?
 

well what i think that could be the muffler or the cat probably they are braking apart inside i think, because they have some kind of metal filters inside

Re: rattle, car's cold, exhaust?
 

im pretty sure the problem was my catalytic converter.. i was underneath my car at work and examined it..
i still hear the rattle.. but i ignore it because a new one of those is pretty expensive..