So I just bought a 2006 trailblazer. So far is a nice truck. The only thing I can find wrong with it is it has a quarter million miles on it. And it's super clean. Anyway I've noticed that it sounds like a damn milk truck when it's taking off. The motor makes its own noises when accelerating but there's something else that starts whining too. What is this? Also with it having so many miles, what should I do to keep it running and in good shape? Also this is the first 4wd vehicle I've owned so I know **** about any of it.