Strange humming sound?

[chylld]

Ok i've got a very annoying sound in my car that's only recently started to develop. Car is an 06 civic sport.

When driving along, I get this kind of humming/resonance sound happening. With the help of some software i've narrowed the frequency of the sound to 275hz; it's very distinctly a single tone.

Here are the clues:

As i drive faster, it gets louder.
On rough surfaces, it presents itself more.
The pitch does not change, regardless of how fast I'm driving.
It still happens when the stereo is turned off.
I wound all the windows (inc. sunroof) down/up again and that didn't fix it.
The sound is present throughout the tyre pressure range of 35-39psi
(possibly unrelated) When i go over harsh bumps, i can hear something loose hitting the underside of the car with a metallic sound.


Any ideas anyone??

[egSi]

is this sound recent or have u always had it?

[chylld]

definitely recent. before it was just the low frequency road noise rumble... now there's this mid-frequency "road noise" to add to the mix.

[[T][L]]

maybe wheel bearing???

[chylld]

[L]']maybe wheel bearing???

yikes... that would be bad :( i haven't touched any of the mechanics on what's still a practically brand new car, i'd hate to think that's the problem.

right now i'm thinking about how to explain this to the honda service dept. i've noticed that the car has developed what are now sounding like mechanical noises, like clunking from the undercarriage and noises from the engine bay. apparently there is an engine mount issue with the 06 civics which they've started to remedy in the US, i'll probably grab the TSB and dangle it in front of honda aus' face.

[chylld]

i've gotten hold of a voice recorder and will try to use it tomorrow to record the sound. one very interesting thing that i noticed, is when i run over ruts and potholes in the road, the 'thud' sound i'm hearing is exactly the same frequency as the humming sound. and because of its aural characteristics and that it's always a single pitch, i think it's just some panel or part that's resonating... which is very fixable. :)

i'm actually thinking, this might be a positive sign of my sound deadening... it's reduced resonance noises from so many panels that there are only a few distinct ones left... but unfortunately because they are distinct, they stand out like sore thumbs :( same kinda phenomenon as quietening your pc... eliminate your noisest part, and the next noisiest part becomes your biggest problem.

[chylld]

ok i did a recordng but unfortunately couldn't find a peak around 220-275hz... very frustrating, because i know i can hear it!! aargh.

don't know what to do now. the road noise is ridiculous and i've returned the car back to as stock form as possible, save ripping all the dynamat out. is it possible that adding dynamat actually increased my noise level??

[Baopham]

wheel bearing, mount, strut.. whateva it may be.. just take it to honda.. they should cover it under warranty..
the jazz's had huge problems with wheel bearings.. they were replaced without question under warranty at my work.. just take it to a honda dealer and let them deal with it.. warranty is ur friend.. and the dealers nightmare.. take advantage of buying a new car...
if its hardly noticable.. they will most likely tell u that there is nothing.. but to go for a drive with one of the mechanics and pin point out the noise to him.. shouldnt be a problem

[Disco-d]

maybe its the wheels....try changing them....

it sounds like i might have some wheels that are feathered...it happens when the surface of the wheel is not even.
i have the same problem.

when my car goes faster the sound gets louder, i slow down and its not as loud.

try getting a spare set of wheels

[dettoz]

yea i'm thinking its the tyres.. have you changed them recently? i find the cheaper the tyres the more sound it produces.. well thats my theory :p

[chylld]

i haven't changed them recently, and at 8500km i can't justify changing them either :) i definitely don't like them though, and not just because of the noise... but they have hardly any grip in the wet, even with the right tyre pressure the abs kicks in on almost all downhill stops :(

i've delegated new tyres til some time in the future, and am actually going to use them to my advantage as they'll better help me find the weaknesses of my car, i.e. where noise is seeping in or where vibrations are causing resonance noises. then after all that's done, a switch to quiet, comfortable tyres will be the icing on the cake! :)

[Limbo]

for a new car take it back and ask them to figure it out!

But seriously it sounds like tyres. Check to see if there is not something stuck inthe tyres that is making noise.

[chylld]

which are the good honda service depts in sydney? i've only tried the hornsby one so far and the last time i complained about noises they just gave me the "we had 3 people listen to your car and couldn't hear anything" excuse. i'll be giving them another chance for my 6 month service later this month, if they don't perform this time i'll definitely look to someplace else :)

funny thing is, i tried to record the sound but upon performing a spectrum analysis, no peaks showed up at all. i artifically pushed frequencies to pinpoint the annoying sounds, but still they're very quiet... seems like it's only a problem for me, and when i'm sitting in the driver's seat.

[Jazzle]

rick damelian in leichart or collins in rockdale.. they're good.