3.4l knocking

I got a buddy with a 3.4l with roughly 250k miles. When he bought the vehicle around 5 months ago there was low oil levels but everything sounded good. He had noticed a quiet ticking sound a few days ago. Now today, he washed it and was driving it when the sound became a pretty harsh knock. Trying to figure out if there are other issues that could be causing this loud of a knock that isn't a spun bearing?

 

You can do a compression test on the motor to see if the internals are worm out. Psi sould be 127 psi for minimum and 178 psi for maximum

 

I would check the spark plugs as well if there is any oil on it should show signs of wear and tear on the motor

 

Since you noticed the louder knock after washing, it wouldn't hurt to check his spark plug wires. Get it into the dark, let your eyes adjust, and use a water bottle to spray a mist of water on the spark plugs. Look for jumping sparks. Doesn't cost anything or take too long to try.
Matt