Sporadic Road Groove Type High Pitch Vibration

tomahan

Our 1995 Mercury Cougar has developed an intermittent or sporadic high frequency/pitch vibration that when it occurs, simulates the sound of driving over road grooves or a washboard. When it first occurred, this is what I thought it was, just road grooves. But now it occurs sporadically, seems mostly under acceleration, and only for a short moment. There doesn't seem to be any predictability to it, but it does occur regularly over smooth road. Could this be a transmission problem? Thanks for any help.

blackgtp

Is the exhaust contacting something as the powertrain flexes under acceleration? Is a heat shield vibrating? Can you feel the vibration in the seat, the steering wheel, the floor, or can you just hear it not feel it?

tomahan

It's something more noticeable to the ear than feeling it, possibly due to each occurrence lasting only a second or two. I know it's tough without a test drive to know, but I don't think it is anything like exhaust rubbing, but think I'll climb under it and take a look, see if the mounts are loose.

One thing I was wondering is if there is anything in the transmission where any kind of slippage or something might cause this kind of trouble?

Thanks for the help