Last night my engine started getting weird on me. Here are the symptoms: When the car is driven, between 2500 and 4000 rpm there seems to be a loss of power, kind of lags, then picks up power again. When i pull on the throtte in the engine bay, it makes a quick little whooshing noise for a second. What does it sound like? Would this be covered on my 2 year/50,000 mile extended warranty? thanks for any help at all guys!