Sounds like RF noise. Sometimes It can come through your speakers even if you don't have the radio on. What plugs are you running? Did you recently switch? Most modern plugs have an internal Diode that helps prevent RF interference but plugs like the copper NGK R's don't have any sort of resistor. This can be exacerbated by leaking plug wires or OGF in the wiring.
Thanks for the suggestion. The noise has been there since I got the car back in 2012. I'm running a stock ignition points system with original plugs and reproduction wires. If it was an RF issue I would think that with the engine at let's say 2200 RPM whether in 3rd gear or in 2nd gear going at a slower vehicle speed in 2nd gear, the noise would be there but it's not. I've also been going down hills at speed and pushed in the clutch to allow the engine to go to idle or even shut the motor off at speed and coasted and the noise was there. Goofy thing too is it's always not present and could be due to a tailwind or headwind. Being an audio installer since the late 70's I did have ignition system issues with something like a bad wire arcing to ground but it was a ticking noise and then if I had a whining noise, sometimes it was a bad diode in the alternator allowing more of an AC ripple to get into the DC. Again, thanks for your input.
Sounds like RF noise. Sometimes It can come through your speakers even if you don't have the radio on. What plugs are you running? Did you recently switch? Most modern plugs have an internal Diode that helps prevent RF interference but plugs like the copper NGK R's don't have any sort of resistor. This can be exacerbated by leaking plug wires or OGF in the wiring.
Thanks for the suggestion. The noise has been there since I got the car back in 2012. I'm running a stock ignition points system with original plugs and reproduction wires. If it was an RF issue I would think that with the engine at let's say 2200 RPM whether in 3rd gear or in 2nd gear going at a slower vehicle speed in 2nd gear, the noise would be there but it's not. I've also been going down hills at speed and pushed in the clutch to allow the engine to go to idle or even shut the motor off at speed and coasted and the noise was there. Goofy thing too is it's always not present and could be due to a tailwind or headwind. Being an audio installer since the late 70's I did have ignition system issues with something like a bad wire arcing to ground but it was a ticking noise and then if I had a whining noise, sometimes it was a bad diode in the alternator allowing more of an AC ripple to get into the DC. Again, thanks for your input.
driveline harmonic resonance