Access my wallet using a 16 digit passphrase I had a wallet years ago on a PC I sold. I mined bitcoin on it and what not. Recently I found a 16 digit passphrase I wrote down for my wallet. That is all I have and probably all I needed. If I only wrote down the 16 digit passphrase that means that's all I probably needed to access it anytime. I'm 99 percent sure I was using bitcoin core but I'm not too sure. What I do know for sure is that I have my 16 digit passphrase. My question is how can I access my wallet with my 16 digit passphrase I got?
Unfortunately, that 16-digit passphrase is likely the password to decrypt your bitcoin core wallet.dat file. So you'll need to have that file in order to access your wallet.

It could also be a BIP-38 protected paper wallet, but it doesn't sound like you have one of those. 

Your best bet may be to search every email inbox, dropbox account, backup hard drive, or whatever else you may have, for either a backup of your wallet.dat file, or evidence of an account with an online wallet service.