Valve springs are components found in an engine that help control the movement of valves. They are like little springs that ensure the valves open and close at the right time, allowing the engine to work properly. Full definition
So, any owner of these models are all requested to have their engine valve springs fixed so as not to make things worse for the owner and the company. (topspeed.com)
The intake valve spring on number one was broken. (bugeyeguy.com)
The tapping noise ended up being a broke valve spring that was going to cost a few thousand to do. (cars.com)