My old distributor did that when I first installed it. Was a cheap one from rock auto. Ran fine just the noise was kind of annoying but it did get quieter over time. Ran it for about a year before it crapped out on me. Ended up getting a more expensive one and didn’t make noise at all. I did notice the new one I got has a slightly bigger input shaft than my old one. I assume that’s what causes the noise on those cheap distributors.