I have a 89 NA with about 5k miles on a completely rebuilt motor. Everything seemed fine until today when I was driving home. At first it was a little clanking noise it stoped after a minute so I didnt think anything of it and i continued driving home. When I went to start my car about an hour later the sound was noticibly loud when I gave it a little bit of gas it got much louder so I shut the car off. Any ideas on what it could be? Thanks.