[quote]When i drive my car makes this dog whistle noise an yesterday i got the serpent belt an pulleys replaced but the noise is still happening. It does feel like i have a leak somewhere but it’s hard to pinpoint it. The noise only happens when my car is moving so i don’t know what the deal is.[/quote] Ok first: Year, Make, model of the car? Why did you have the serpentine belt AND the pulleys replaced? Who did the work? If the noise happens only when I he car is in motion, then it very likely is not the drivetrain making the sound. If it is a whistling noise, it is most likely a window seal, that is bad, or even possibly a window that is not closed tight. When seals dry rot or somehow get pinched to where they no longer fit properly, air movement around them can create a very annoying harmonic that sounds like a whistling noise. If it is bad enough, the whistle can get to where it sounds more like a kazoo, for lack of s better way to describe it. The noise usually only happens when you hit a specific speed causing enough air flow over it to create the sound. So, when driving, have no other sounds present like the air conditioning fan, or radio, and have someone sit in different seats intently listening when the sound is there, and try to isolate the window or door even that the sound may be coming from. If it were an engine it may be only at specific rpms which may mean there is a vacuum leak. If it were the transmission, then it would only be heard at specific speeds or maybe even in a specific gear. But it would be a whine, not a whistle. If it were even wheel assembly possibly making the sound, it would be at a specific speed, but also would be a more mechanical whine or grinding noise. But as for the belt and pulleys, it sounds like you just got taken, unless there may have been some other issue there that required that. Any reputable mechanic would know a whistling isn't a belt. That's a whine, and very distinctly different. If you have ever heard a car drive by you in a parking lot that is making a whining noise as it turns, that would typically be the power steering pump either failing or low on fluid. So change a belt? Sure, they do need that every few years. Pulleys? Not unless something was severely out of whack, or you had them intentionally install a step of under drives for performance sake.