why or where is the metallic rattle coming from when the car is at exactly 42 and 46mph. doesn't matter if accelerating or coasting... and only at those speeds
Probably the tires are causing a "Harmonic" vibration. That's a secondary vibration caused by another source ... sorta like a loud bass will make a glass rattle. Your tires are probably out of balance and that speed is where it generates a secondary vibration
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