It drives fine except for the noise. It's just sitting waiting to be fixed now though. The belt is tight, and there is no smoke. I'm not sure if it has a timing belt or timing chain, it has dual overhead cams. I'll start by checking the oil.
Sounds like a really worn out and loose idler pulley bearing or any belt driven bearing. OR a dry camshaft from a plugged oiler galley.
Use a 3-4 foot section of garden hose or any larger hose; one end to your ear and one end down around in the engine areas to isolate the sound. (unless you have access to a mechanics stethoscope).
DONT DRIVE IT LIKE THIS.