2005 Ford Taurus SE Gear Changing Problems/Check Engine Light/Trouble Starting
I drive a 2005 Ford Taurus SE which has about 98,000 miles. Recently the car has been having performance problems, characterized mainly by hesitation and jerking when going from one gear to the next higher one. It is especially noticeable when I am not putting a decent amount of pressure on the gas pedal. It has not occurred recently but there have been times when starting up the car that the car does not immediately respond to my foot pressing on the gas pedal, causing an initial pause in power, after which it will jerk to life and accelerate in speed. The "service engine soon" light has come on and then gone off as well. Putting a higher grade of fuel in the car has caused the light to go off on occasion but the other problems still seem to persist. The car also generally sputters when I turn the key for a second or two before starting up. Furthermore on occasion I have noticed a noise coming from under the hood that sounds like a belt making something of a whining noise.
Any ideas as to what the problem could be/steps to take to figure out what is wrong? Took it to a trusted mechanic, said he took for a test drive and didn't notice any problems.