engine oil sludge

例句：

1. 1. The old car's engine oil sludge was causing the engine to overheat.
   这辆旧车发动机的油泥导致发动机过热。
2. 2. To keep your engine running smoothly, it's important to regularly clean out the oil sludge.
   为了保持发动机平稳运行，定期清理油泥是很重要的。
3. 3. The mechanic had to remove the engine oil sludge before he could replace the engine.
   在更换发动机之前，机械师必须清除油泥。