Engine started it ran very rough, missing badly?

Hi,

An engine knock is usually an indication of a bad bearing. The crankshaft main bearings and the connecting rod bearings can both create this type of sound.

Take a look through this link first. It explains different engine noises, the probable cause, and what is required for repair.

https://www.2carpros.com/articles/engine-noises

At this point, you will likely need to remove the engine and oil pan to inspect the bearings. Start with the crankshaft and connecting rod bearing. If you look below, I attached the directions for how to perform the inspection.

I hope this helps. Let me know if you have other questions.

Take care,

Joe

See pics below.