Alright, let's see.
ASM would work but move consumes 4 chars already.
I could run the code itself infinite times and print ASCII 31 0a (49 13? I guess. Idk) repeatedly. But that wouldn't be a programmatical loop.
><> (fish) works.
1n
That's it. Two chars.
Edit: I just realized, that just prints 1 repeatedly and doesn't add a newline. So..
1nao
4 chars. That should do it.
Edit2: Wait, did fish win this thing? I thought somebody would write some crazy machine-level code(which is highly unlikely; as I said, that would take 4 or more chars - just to print it) to nail this. Well, I guess ><> wins then.