问：高速公路上的大众polo过热

嗨，我希望您能为我提供帮助，因为我处于智慧。大约2个月前，我的1.4 TDI Polo在高速公路上过热。停止流量没有过热。机械师为其服务，取代了水瓶，恒温器及其外壳，并冲洗了系统。一周后，它再次在高速公路上过热。然后，一家散热器商店检查了气体排放，没有测试液体的反应。在更换散热器的同时，他们发现中冷器外壳被错误地安装，损坏了中冷器。它已经修复，汽车的性能肯定得到了改善。一切都很好，持续了大约3周，根本没有过热甚至温度峰值。12月24日，我开车比平时更远，在下雨的同时再次过热。 I drove very slowly to the nearest garage, as stopping next to the road in my country is not safe and with the rain I would not have been able to see much. Someone helped to brigde the fan so that I can reach my destination, but the car kept on overheating. I stopped and waited for it to cool quite often. When returning home on 26 December, if I kept it below 100km per hour it was ok, but on hills the temp climbed. I am not sure what could still be wrong, and everyone I spoke to were confused as the car has not overheated once in stop-go traffic, only on the freeway. Any advice or ideas of what else to check/test would be greatly appreciated.

我的车有133000英里。
我的车有手动变速箱。