1991 GMC Van V8 Two Wheel Drive Automatic 45000 miles
At certain point in acceleration, speed not a factor, does it even in cruise control, will make a sound EXACTLY like I have drifted over onto the highway rumple strip. No additional vibration is felt, just the noise. Can decelerate or accelerate to make it stop.
Have never experienced anything like this in any vehicle. Any suggestions as to cause.