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Been having trouble trying to find out what is causing this annoying buzzing/humming noise.
The noise only comes out above 140+ KMH and it stays constant. Sometimes even audible above 120kmh+.
Some facts:
1. Car is a 997.2 C2 Manual, done about 65,000km.
2. I have replaced all 4 wheel bearings and my tires are new (less than 2,000miles). The noise still persist. Tech at Tire shop says my tyres are fine, no feathering/cupping.
3. Engine oil, transmission oil, diff oils are all replaced.
4. I tried to clutch in (neutral) when the noise is audible, sound still there.
5. No change in frequency/pitch on Throttle modulation / lift off
6. No change in frequency/pitch of the buzz/humm when I make directional change to the car
7. Tried with Air Conditioning switched off and switched on. no difference.
The sound seems to be coming from the front. (my Dashcam seems to pick up the sound quite clearly).. Sounds like a loud Fan/Hair Dryer blowing?
Managed to record a sound clip of how it sounds: (See that it gets louder from Second 20 onwards)
Does it always happen and always at almost the same speed? If so, I think there's a harmonic from the tires being transmitted through the suspension setup creating that noise.
Does it always happen and always at almost the same speed? If so, I think there's a harmonic from the tires being transmitted through the suspension setup creating that noise.
Hi Petza914, yes the sound happens at about 140-~kmh ish. Always at around there and above. Any idea on how to 'fix' that if its really harmonics from the tires+ suspension setup?
Hi Petza914, yes the sound happens at about 140-~kmh ish. Always at around there and above. Any idea on how to 'fix' that if its really harmonics from the tires+ suspension setup?
Do you have a buddy with a 997 who runs a different tire where you could swap his wheels over to your car and vice versa to do a test? You'd be 5esting yo see if his setup does the same thing on your car and vice versa.
Do you have a buddy with a 997 who runs a different tire where you could swap his wheels over to your car and vice versa to do a test? You'd be 5esting yo see if his setup does the same thing on your car and vice versa.
Good idea. Will try to do find a set to swap/try on!
I'm going with am undertray of the car not being seated correctly and catching the wind. I had a similar sound coming from the sunroof even when it was closed.(non Porsche car).
Turned out to be the seal and at about the same speed you're talking about made the same noise.
I couldn't hear the video that well but I saw a video of a guy that had a similar "buzzing" at speed. It was the passenger side mirror resonating. I think there are a few issues reported on RL and 6Speed of both the rear view mirror or side mirror resonating if they become loose.
I'm going with am undertray of the car not being seated correctly and catching the wind. I had a similar sound coming from the sunroof even when it was closed.(non Porsche car).
Turned out to be the seal and at about the same speed you're talking about made the same noise.
Hmm ok will try to check the under-trays. My car has a custom fitted Turbo bumper, but I made sure I ordered the right under-trays and also wheel arch for the C2. Will see if there are any gaps/holes.
I couldn't hear the video that well but I saw a video of a guy that had a similar "buzzing" at speed. It was the passenger side mirror resonating. I think there are a few issues reported on RL and 6Speed of both the rear view mirror or side mirror resonating if they become loose.
Good luck.
Thanks for the input. The sound doesnt seem to be coming from the side mirrors, more from the 'front'/nose of the car.
If you listen to this clip, around seconds 10 onwards to second 20, the sound becomes more apparent/loud.
Hmm...occams razer. Yea I would zero in around that. I would also make sure to check the front wheel liners well. Mine were cracked and had bits missing.
Hmm...occams razer. Yea I would zero in around that. I would also make sure to check the front wheel liners well. Mine were cracked and had bits missing.
Haha yes, if it is the bumper, i will be in a mess trying to figure out where exactly the 'sound' may be coming from. Previous owner did quite a job fitting it in with turbo parts (undertrays, fender arches and so on).
Just an update - for future reference to those who experience similar buzzing/noise. I managed to find the source of the sound, it is coming from the side of the windscreen, caused by improper sitting of the windscreen mouldings.
Video here showing how the rubber moulding goes in with just a soft press. I guess at speeds of 140-150kmh, the wind pushes it in and thus causing the buzzing noise.
04-29-2018, 01:05 AM
Buzzing/Humming Noise at High Speed
