I just purchased an '01 Taurus SES and everything on the car seems to be ok except thatevery time Iaccelerate (or pressing the gas) I feel some slight vibration.Once I am off the gas or coasting it's smooth as glass. The dealership where I purchased it say they serviced it (supposedly) and the "check engine" light is not on.Also while I am on the gas I can just barely feel some very slight surges whether decreasing or increasing in acceleration, I mean it's almost hardly noticeable. Nevertheless, I'm thinking maybe there is some small vacuum leak somewhere. Any ideas, anyone?

 

Try some fuel injector cleaner in the gas tank.

 

Sure, a vacuum leak could happen. Also try taking off both battery cables and cleaning them. This will eliminate any cable problems AND reset any offbeat problems in the computer system (if the injector cleaner didn't help). Also you may try a different brand or higher grade of fuel, but usually in normal circumstances injectors aren't that much of a problem. My '88 Mustang had surging problems due to a bad speed sensor once.