Automotive Forums

I have a 2002 Ford Taurus SE with 3.0 V6 (basic engine) and automatic transmission.  Vehicle has 175,000 miles, new tires and recently rebuilt transmission.

I have noticed lately that there is a rolling vibration when cruising at highway speeds.  By rolling, I mean that the vibration comes and goes in cycles.  It is most noticeable when I am traveling on smooth roads at 60mph plus.

What happens is I that begin to feel the vibration softly at first, but then it begins to build, reaches a peak and then fades away.  Then there will be a few seconds of smooth riding and then  it starts again.  It is more pronounced at higher speeds, and mostly when traveling at one speed.  I do not seem to notice it so much when accelerating or decelerating, but it is always there when the cruise control is activated.

The vibration is never huge, or teeth-jarring, but it is noticeable.

Can you help me figure out what may be causing this?

Thanks!  

Tires can do this!  Make sure they are balanced correctly. Otherwise I dont know.  Maybe 175000 miles has something to do with it!  
Want better gas mileage? http://gozap.us/e16

Thanks for the response!  I considered tires, but I've never experienced tires having this kind of vibration before.

I have to say, even with 175,000 miles, this car is pretty tight.  No weird noises, tendencies or anything.  Except for this weird vibration, I have no complaints.

This is possibly the best vehicle I've ever owned.  

with that kind of mileage it could be the steering knuckle/s on the tie rod/s are a little worn. Theres no way to grease them anymore and the permanent grease cups aren't really that permanent.

But you could try switching front and rear tires first to see if maybe you got a bad tire. There are other tire defects beside balance.  

Hey funsarlo, if the steering knuckles were worn, would I be feeling it in the steering wheel?

I should have mentioned this earlier, but I don't really feel the vibration in the steering wheel.  Mostly, it's just the whole car that shudders.  

Power steering systems have "dampers" installed to give the driver that "real feel" at the wheel. Otherwise you could steer the car with your pinkie --too easily--and get yourself in trouble. But it is still power steering--not manual--and it can hide some minor steering or balance problems until it gets worse.
The other thing you mention is a recently rebuilt transmission. You only notice it over smooth roads at 60 and over. First off ,,you probably would not go down tobbacco road at 60 since you would wind up in a ditch. So lets say the problem is at around 60.  Could be something in the tranny. These are all guesses of course. I'm only giving guesses on what you have posted and nothing more.