My '84 Honda did the same thing and it turned out that the tread belts were
coming off the tire. So at low speed there was no noticable difference, but
at freeway speed there was just enough slipage inside the tire to cause it
to vibrate left-right dangerously. It wasn't apparent until I had the tires
removed for balancing and then the repairman saw the tail-tell cracks.

"Matt" <rpi04@hotmail.com> wrote in message
news:1122500589.979586.237600@f14g2000cwb.googlegr oups.com...
> The steering wheel on my '89 Civic vibrates noticeably left-right, like
> the car is alternately pulling in both directions, when going 50 MPH or
> better. At lower speeds I don't feel it (or it is slight enough that I
> don't). I checked the tire pressure, and they're all good. Is this an
> alignment or other issue, or just the age of the car showing?
>
> Thanks,
> Matt
>
> PS- Thanks to previous posters for the info on my oil consumption
> problem; after I replaced the PCV valve, head cover gasket and switched
> to Castrol Syntec the consumption dropped off the table, it's very
> slight now.
>