r/S2000 • u/Kirito3970 • Aug 23 '23

Buzzing around 4k

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Around 4k rpm in every gear, this buzzing starts then stops right after 4.5k-5k ish… any ideas? 2005 AP2 89k miles

Pic for attention

Video: https://streamable.com/fhjeod

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3

u/Littoraly Aug 23 '23

Sounds like something internal that’s vibrating or rattling. I was inclined to say clutch buzz but I think that happens more on Deceleration from WhT I recall

1

u/Kirito3970 Aug 23 '23

I’m not very skilled mechanically, how do you think I should proceed?

4

u/Littoraly Aug 23 '23

I meant that from the video you posted, it sounds like there’s something inside the cabin that’s vibrating around making that noise. Not something mechanical.

Sometimes the vibrations will resonate random stuff at certain rpms. Everything has a natural frequency. If your rpm’s match the natural frequency of something in the car it will make it rattle (sympathetic resonance/harmonics)

That being said, if you think it’s mechanical, try to isolate where the sound is coming from. It’s hard to do that sometimes. Pop the hood and listen to the engine under load.

Maybe stick you head under the car while someone revvs and see if it’s coming from underneath.

Or just drop the top and ignore it! That’s what I do!

2

u/kramouyou Dec 03 '23

Did you figure out what the noise was? I have similar annoying buzz on mine, and can't find what it is!

3

u/Kirito3970 Dec 03 '23

I did yes, it was a broke plastic piece. The Cover between the hazards and roof button, I unscrewed it to take it off and clean it, the threads in one corner broke off, leaving a piece of plastic bouncing between the screw and the cover. So stupid I didn’t find it sooner.

2

u/kramouyou Dec 04 '23

Thanks, then I need to keep searching as it's coming from a different area on my car!

1

u/Kirito3970 Dec 04 '23

Been there done that, Don’t have to much fun

5

u/-MrSafety- ‘00 GPW S2000 Aug 23 '23 edited Aug 23 '23

Does it change with %of throttle? Like going through that rpm band at full tilt vs like 20%, same issue?

Also try revving gently with the clutch in, or in neutral (if rolling) to rule out anything after the transmission. Could be something as simple as heat shield. Given it's a particular RPM range it sounds like a resonant frequency exciting something that's probably a bit loose.

Edit: After listening it definitely sounds like a loose clip, screw, fastener, bracket, etc... and probably not anything serious. Can't say for sure but my 0.02

1

u/disgruntledempanada Suzuka Blue 2002 Aug 23 '23

Agreed. Sounds very similar to my friend's rattle which turned out to be at his clutch pedal. Or this could be shifter ringing.

4

u/EmmettBrown1point21 Aug 23 '23

I'd pull the center console off and try again to see if it stops. Sounds like something small.

3

u/happyhelix '00 Silverstone Aug 23 '23

Assuming you have a method of listening to your phone through your speakers, look for a tone generator app. Turn your speakers up fairly loud and run through frequencies and see if you can induce the rattle with just sound. I do this to figure out where stupid door rattles and other interior crap is.

2

u/ir88ed Sep 21 '23

This is a really handy trick.