major engine overhaul

例句：

1. 1. The old car needs an overhaul to get it running again.
   这辆旧车需要彻底检修才能再次运行。
2. 2. The engineers will need to overhaul the engine to fix the problem.
   工程师们需要对引擎进行大修以解决问题。
3. 3. The factory is overhauling its production line to improve efficiency.
   工厂正在对其生产线进行大修以提高效率。