However: engine overheating is an engine problem (timing or engine cooling system, or even low oil level) NOT induced by the a / c system. (mechanics.stackexchange.com)
If your engine is smoking and knocking, it's likely that there is rather excessive engine damage or extremely low oil level. (yourmechanic.com)
Most of the time, an engine knocking issue is caused by low oil pressure or low oil levels causing metallic components to hit each other without proper lubrication. (yourmechanic.com)