Hi all! Looking for a little help. Buying a 3.2 liter with 220k miles. Car sat for 2 months and now has an odd noise that comes and goes. Never consistent. Sometimes runs and drives perfectly, then the next start up a loud knocking, but still runs and drives great. Any ideas? I posted a link to YouTube below (couldn't attach the video?). It is $1,500 and will be used for a beater around town, just don't want to buy it and have to put a new motor in it. Any help is appreciated!

https://youtu.be/ZZVJBkfeRaU