Knocking and pinging. Weird noises?
So lately I have been seeing a lot of V6 new edge mustangs making some really weird noises and I'm afraid I might get them. Earlier they're was one cruising next to me and I can hear like something slapping something as he was stepping on it. There are other V6s that have made that noise too even my girlfriend's sisters car makes it but mechanic said to not pay it any attention. What my question is do any of you guys might know what it is that is making that noise?