I have posted this before but have not found the cause.
My problem is when I am driving normal and trying to maintain a constant speed I get a raspy metallic sound that undulates randomly. If i apply the slightest amount of gas the sound goes away or if I release the pedal completely the sound goes away. I will list what I have found with my car, maybe one of these things will be the cause.

I have a broken bolt on my header heat shield (resonant noise maybe?)
I have cupped rear tires.
I changed my clutch to a Mugen pp/oem disk/toda fw and new TO bearing

My trans changes gears very smoothly.

any ideas on what it could be or does this sound normal.
Thanks guys!

 

Clutch buzz?

 

I was thinking this too as your sound sounds like the clutch buzz I have as well... is it during decel between 3-4k?

 

That doesn

 

about 4k miles ago and I notice the noise as soon as I drove it awile. I changed my clutch b/c of the clutch buzz, this sound is nothing like the clutch buzz... that sound drove me insane. While decelerating my clutch make no loud noises.

 

I think I got the same problem as yours

but I got the noise coming from the rear..

Only at certain speed limit though.. you will notice the noise even more if you at high gear, example 4th, 5th, 6th gear at LOW constant speed, noise will come from the rear...

I got my dealer fixed the broken bolt for me on the heatshield but still there is some growning noise when its around 3000-4000rpm at second gear.

I am going to bring to the dealer again tomorrow..

 

I have that same sound i think.. i know its not clutch buzz because i already have it ...

The sound is exactly between 3000 and 4000rpm through accel and decel after the car is warmed up for a while. I think it has to be exhaust related because i can just rev and hear the sound. its such a weird sound, i be driving in any gear at 4100rpm with smooth sound and drop down to 4000rpm and the sound starts, and then it goes away again right at 3000. its exactly the same every time.

Anyway, things i have done trying to get rid of that sound...

1.Diff fluid change (needed to be done, but didn't get rid of sound)
2.Tightened every single heatsheild bolt from the header all the way back (lol got rid of other little rattles, but nothing on that sound)
3.Just installed megan racing test pipe w/ the o2 anti-fouler trick (love the sound, feel, no CEL yet, but still the sound is there.)

I have an invidia exhaust thats been on the car for about 2 years.. i'm now thinking the sound might be coming from that resonator...I've been searching and read that they tend to go bad. So who knows...this sound is def getting annoying tho

 

so far I had 2 cases been repaired by honda dealer..

-clutch and flywheel replacement ( replaced and reduced noise )
-heatshield bolt ( replaced to new one and reduced rattle or growning noise )

and i am going to try this next.. just for your reference.. I AM GOING TO TRY EVERY WAY TO GET RID OF THAT NOISE from the rear.... god damn annoying...

Trying this since this is the easiest task.
-Jack up rear of car onto jack stands.
-Remove rear wheels.
-Lift up bent tab on nut so it will not tuch the threads when you remove it.
-Remove nut with impact gun.
-Clean the threads on the nut and axle.
-Apply anti-sieze compound to both axle threads and nut threds
-Install nut back on by hand.
-Torque to 220ft/lb.
-Bend tab back down over axle slot. (prevents it from backing off.
-Repeat on the other side.
-Install wheels.
-Remove car from jack stands.
-Drive away click free

Then probably will try this if above doesn't fix..
Require Parts
part #2 the rear wheel hub 42210-S2A-000
part #36 the rear wheel bearing 44300-S47-008

The procedure for the S2000 is covered on page 18-9 of the Helm (factory shop) manual.

You put the car on a lift, pull wheel, attach a dial gauge against the flange on the hub, and then apply pressure (with your hands) to move the brake rotor in and out. If the play exceeds 0.05mm (0.002 in.) then the bearing at that wheel should be replaced. It makes sense to check this every time you do brake work, while you have the dial indicator out to check the rotor runout.

According to the Honda shop manual, the bearings need to be replaced when the end play exceeds 0.002" (0.05mm). No inspection interval is given, but it probably makes sense to check the runout at least every other oil change. Better to replace the bearing before it takes out the spindle.

You will need a breaker bar with a 36 mm socket for the spindle nut and a ball joint popper. I used Autozone's tool loaner program to get these. The bearings do need to be pressed out / in, but I just had a shop do that for $20. Make sure that the shop presses the new bearing in the right direction. The seal is different on both sides.

Bill found the problem. I'm going to try to explain as best as I can. In short, the hub (part that's behind disk that presses onto ball bearing in knuckle) need to be replaced. When we took the part out, I saw a lot of rust dust and black dust. and the sleeve of the hub (protruding part) has worn out about .1 mm. what I think how it happened is, with loose axle nut, hub and the axle wasn't tight. as I'm driving, it was grinding itself and dust were formed inside. when we taught it last time, dust was still there, hence it got noisier. (packed powder...) this time everthing was cleaned before we put it together. so far, I don't have noise yet. but I'm hoping to replace hub and the bearing before fall colors. I'm also hoping that bill will chime in and give us more detail.

I am pretty sure that I have the same problem, my car is at the dealer right now, and the technician says that my driveshaft is loose and spinning erratically. He is going to adjust/tighten it. I'll let you know if that makes my problem go away.

Other possible issue..
Jack the rear up and put it up on jack stands. Start the car up and put it into first gear. See if you can find where the noise is coming from.

With the wheels turning and rear clunking bring one of the wheels to a stop using a board or your shoe etc. If the noise stops when the wheel stops then chances are its one of the CV joints on that axle. Likely the inner joint.

As you stop that wheels rotation the other wheel will increase in speed and the prop shafts speed wont change. Listen for the speed of the clunking. If it increases then its associated with the other wheels axle. If the clunking doesn

 

"You put the car on a lift, pull wheel, attach a dial gauge against the flange on the hub, and then apply pressure (with your hands) to move the brake rotor in and out. If the play exceeds 0.05mm (0.002 in.) then the bearing at that wheel should be replaced. It makes sense to check this every time you do brake work, while you have the dial indicator out to check the rotor runout."

I actually pulled the rotor all the way off (with force) after I removed the caliper.
I probably screwed it up

Maybe my rotor is loose and wobeling around when I let off the gas and it is rubbing against the pads and shaking back and forth.

What do you think?

 

Anything possible
lets keep this thread alive with update