I have a 2002 Explorer XLT with 30,000 miles on it. There are a few problems I am having with it. First, there is a howling sound that comes from the air conditioning when I accelerate (very annoying). Why is that? Second, when I go over speed bumps the front suspension or shocks (I don't know) are making a rubbing or dried up sounding noise? In addition, the engine seems to be sputtering when sitting in traffic. If I could get some answers or courses of action to solve these problems, I'd definitely appreciate it.