imported_jwald

So I started my car one day after it had been sitting outside in the parking lot all day (in the cold). I let it warm up for a couple minutes before driving off. All of a sudden at around 2500RPM i get this clanging or rattling noise. The weird thing is it only happens when accelerating, i.e not in nuetral, and it only happens between 2500-3250 rpm. When the engine warms up, the noise goes away and doesn't happen at all. I thought maybe it would be transmission fluid or some fluid not working properly, but i had all fluids checked any everything is ok. The noise seems to be coming from the center of the engine, and near the bottom, that's why i suspected transmission, but apparently not. Any ideas?

Sorry for the long post, thought i'd give you all the details though

imported_94EG6HB

heat shield

look underneath..

imported_jwald

good thinking i'll check it in the AM

chris_si98

its not your heatshield if it stops at a certain rpm. Atleast it shouldn't be..

I get this too.. i've never really bothered to track it down.

imported_jwald

oh yeah, i'll check the heat shield, if that's not it, i'll do a more comprehensive check for loose things under neath, when i change my rims and stuff for summer

chris_si98

so what was the verdict?

Mine was doing the samething.. and it was really bugging me.. and it got worse too.. it happened at idle.. so i put it on the hoist and it turned out it was my cat bolts... i didnt fully tightened them when i removed my headers and put them back on.

Its always the stupid things

imported_jwald

sorry haven't been able to check it, took an emergency ski vacation instead, i'll check it next week when i change my rims out and clean the air filter. i don't think i have the same problem since i am running stock headers still\ (although thinking of changing them this summer)

electronblue

iTrader: (1)

Mine made that noise too during the same RPM range. Turned out to be the catalytic converter, I manged to break the baffles inside.

imported_jwald

that would make sence, i'm gonna check out the car this weekend,

szuberi

center front and down below from the engine....its definitely the heat shield and is a common occurance in civics.

Xscorpio

yea i had the exact same problem, i took all the sheilds out. cus sooner or later, they get all lose and started to rattel.

imported_jwald

what heat shield am i looking for, i couldn't see anything loose while i changed my rims, the shield on teh header was tight, and the cat was pretty tight as well. can anyone help me locate it?

imported_Moe_Mentum

THey might be takling about the heatshield below the car up front on the exhause.. Not in the engine bay. When your down there shake the cat and see if it rattles. I had the same problem and it was my Cat.

chris_si98

theres a heat shield over your cat and under your cat.. give them a good shake (not too hard) and see if they vibrate and make noise.. also check the one on your exhaust manifold.. there should be one in the engine bay and one on the upper side of your downpipe before it hits the cat

imported_jwald

ok thanks, i'll take a look, the one on the bottom of the cat seemed to be good and tight, but i didn't check above the cat, i'll look for the exhaust manifold part too, but its gonna have to wait till thursday or the weekend. thanks for the help thus far guys

CaptHowdy

heat shields rattle when you hit their resonant frequency.. the looser they are.. the wider the band, heh.

I remember in my '96 Si it would only rattle when I left off the throttle.. I had so many people ask me if the car was turbo, hahaha.

I was actually kinda upset when my bro ripped it off

imported_jwald

ok so i just managed to check things out today, and all the screws on the heat shields were good and tight, however the heat shield above the cat is so flimsy that i'm thinking part of it is actually bending or the whole thing is shaking and rattleing on the cat or another metal bar (name slipped my mind) that runs to the tranny i think. I was thinking to take it off, but i can't get a bolt off cause its above the cat and my tools aren't good enough to get in there. Anyone have tips on how to get in there to get the shield off? other wise i'm just gonna buy some tin snips and cut the flexible part of the shield away and see if that works

chris_si98

are you talking about your linkage? LOL

imported_jwald

yeah, the heat shield is hitting the linkage or the cat itself i think
i'll try cutting it up/off on the weekend...the shield that is not the linkage

imported_jwald

just took 9/10 of the heat shield off, hopefully this solves the rattling, i'll let you guys know later after i take it for a spin. I hope that's all it was!