99666

Searched high and low, but couldn't find anything similar.

Especially noticeable at :20+ and :45+. You'll have to crank your sound up and turn your bass down.

The sound profile: low whirring, like a "wah wah wah" frequency once per half second at low speeds and doesn't seem to speed up with higher speeds. Disappears under acceleration due to exhaust, and shows up again when cruising at high speeds on freeway. Low pitch, tough to hear, but certainly noticeable.

I need to replace my power steering reservoir, but I can't imagine that could be causing a low frequency harmonic sound. You can hear the high pitched squeal from that in the second half of the video.

Car details: lwfw, gt3rs clutch, speedtech 3.0, 72lb injectors, k16/16gs.

The audio is from driving at 20mph on a smooth, level surface. Thats the best I could get since it's too noisy in the car at higher speeds to pick it up.

pancing

Change your trans fluid and see if the noise is still there.

Carlo_Carrera

Can barely hear it. I wouldn't worry about it until something breaks.

deadendd9009

Replace the oil in the transmission, but before filling it up, look at the magnet. If its bunched up, you might need new pinion bearings. This isn't DIY friendly, but it can be done.

99666

Good call on the tranny fluid fellas! I know it's tough to hear in the audio provided, but the sound is more atmospheric when driving the car, and it's driving me a bit nuts.

2fcknfst

The exhaust sounds nice.

smac951

I have a similar sound as of late. I think it might be the power steering pump.

k9turbo

if you're hearing an occasional high pitched "tea kettle" type "whistle" and it stops when you engage the clutch. that's the infamous valve in the PS res resonating as outlined in TSB 4897. such an old problem, i would've thought most of these would have theirs replaced by now.

a water pump impeller also will make noise wobbling on the shaft prior to catastrophic failure. but that's a wild guess as i was unable to hear anything in that clip other than exhaust.

maybe the car is possessed after seeing your user name. anything is possible. GL w it.

99666

The PS reservoir is most certainly doing the tea kettle thing.
But the sound I am hoping folks can hear is more of a loping of the engine/exhaust note. Almost as if it's the result of a vibration. It's noticeable in this video more so.

I was able to replicate it in neutral at about 2-3k rpm:

.

krp220

i have a very similar sound that i have been trying to diagnose as well. i didn't notice it until i had an upgraded 997 trans mount, TS motor mounts, and 3" speedtech exhaust (with 100cell cats) installed. transmission fluid was also done
same symptoms as you in regards to speed, but without the high pitched noise, just the "womp womp womp" rotational noise
how long have you had your exhaust? i really don't think it's that but thought i'd ask
i assume the noise goes away when you put the car in neutral? that leads me to think it isn't a wheel bearing, loud tires, etc

s65e90

Tire noise? You also changed the mounts to something harder, maybe just amplified the NVH

krp220

tire issues (feathering, flat spots, etc) would cause a rotational noise, right?
the mounts adding more NVH isn't lost on me: i expected this, but my bigger concern, and the OP's, is the "womp, womp, womp" noise and not just the constant NVH. i assume it would be constant at least, unless you are implying the mounts would bring out that rotational noise

T Kono

I have noticed this on other cars as well, and none had operational problems. I finally convinced myself it was simply harmonics.....that is, a bunch of different sounds (waveforms) being produced by various parts of the car, all converging and creating "new" sounds (converging waves), and the accompanying peaks & valleys. Pure conjecture on my part without any real knowledge, but I did sleep at night and stop worrying about the sound rhythms.

99666

Thanks for all the responses!

The last video in post #9 is in park/neutral, so the sound is not related to tire noise or driving oriented other vibrations.

I thought maybe a vacuum leak, but I fixed all boost leak issues over the weekend and it didn't change anything.

The exhaust was install a few months ago, and this sound has been slowly coming on the past month or so.

Since the car has a LWFW and performance clutch setup, I am starting to wonder if theres something going on there. Could it be slave cylinder or clutch related?

I have new motor mounts coming, but I'm pretty damn sure that isn't the issue.

99666

Bumping this. Still hoping for a way to start diagnoses without sending to shop for bottomless invoice. Thanks!