S2GeeZy

whats up fellas (ladies),

i just finished installing my sound. stock head unit....diamond's in the front and 2 triangle bazookas in the trunk powered by an eclipse amp. anyways after the install, i was listening for any kind of strange noises and what i came across was not what i had expected. the usual rattle from the rear tray was corrected but as i test drove the my baby i noticed a slight vibrating / rattling sound when i would accleerate then decelerate (@ 3000 k rpm) it also made this noise when i rev'ed it in neutral. the noise appears to be coming from the rear of the car. i can't pipoint it though. i've checked the engine bay (heat shield) and nothing, so i'm pretty sure its coming from the rear of the car. so my question is: anyone else with this problem?? the next time you get in your car check it out. slowly accelerate to @ 3500 rpm and release. when i do this i get that aggravating vibration. any ideas?? its driving me ape shiet

thanks

S2GeeZy

ttt

HondaS2000Tuner

check all the bolts on your exhaust piping (expecially if you have aftermarket exhaust system). Mine rattled because the exhaust pipe lost a bolt and it hitted against my transmission casing. problem fixed after all the bolts were replaced and fixed. It could also be you cat heat shied just rattling. I suffered that a bit too.

Tuner

slalom44

The sound you are describing sounds like a classic example of harmonic resonance. This is when the frequency of vibration of the engine is the same as the harmonic frequency of something else in your car. When harmonic frequency is attained, the engine vibration magnifies the intensity of the vibration elsewhere. Drive shafts and exhaust systems are "tuned" (with resonators, weights, shaft diameter, and hanger locations) so as not to resonate within the frequencies the engine generates. But anything can have a harmonic resonant frequency, including a loosely fastened spare tire. It just so happens that 3000 RPM is the frequency that magnifies the vibration you're getting.

It could be a panel with a loose fastener, an empty soda can, the amp attachment, an unsnug speaker attachment - almost anything. Once you find the source, you can tighten it down to eliminate the harmonic vibration, or put some dampening material in between fastened items, such as rubber or felt washers to absorb the vibration.

You have probably experienced harmonic resonance (distortion) in your car stereo system sometime in the past. Have you ever had a car that when only one certain bass note is hit on the stereo, it feels like the whole car rattles? That particular note is hitting the harmonic frequency of something in the car.

S2GeeZy

wow. thanks. i never knew about harmonic resonance. i guess i should check all the bolts for my exhaust and heat shield....then double check all my paneling......seems like a very exhaustive search!! damn.

thanks to all who commented. i'm hopeful that its not something associated with the motor or drivetrain.

S2GeeZy

any other opinions out there?? has anyone else experienced this?? i wonder if its my stero install or my exhaust??

WRS2K

I'm getting the same thing, dude. Haven't pinpointed it yet, but the sound goes away once the car is fully warmed up.

The light rattling noise comes on at 3K whether accelerating, decelerating, or revving and holding in neutral. I have an aftermarket dual exhaust.

Haven't figured it out yet.

sky-chicken

Check your cat ! Have the same problem. Honda has to replace it because of 10 years warranty on the cat. On mine there was some parts loose inside the cat.

S2GeeZy

wrs2k, btw, what year is your car? mines a 2002

if ya figure it out, lemme know!!! this may sound messed up but im glad i'm not the only one sure wish i could get rid of the sound though. i gonna check the underside of the car when i change my oil in about 500 miles. i've been contemplating whether or not to bring it to the dealership....i hate leaving my car at the dealership, something always comes back fuked up!

anyone else out there?? maybe someone who's corrected the problem?

WRS2K

maybe we should all get really detailed to diagnosis the problem in a truly collaborative fashion so as to avoid dealership screw ups.

it's a light rattling noise and it's right at 3k under load.

also does it when i hold it at 3k in neutral.

mine's a 2002.

my car is lowered so maybe i scraped on a speed bump and jarred something lose. but since it seems to go away once warmed up, it may well be the cat or my comptech exhaust.

i'm going on a drive tomorrow with a reliable honda service guy. i'll report back to see what he has to say about it.