The engine control unit regulates the following temperature ranges: • 108°C/226°F = Economy mode • 104°C/219°F = Normal mode • 95°C/203°F = High mode • 90°C/194°F = High mode and control with characteristic map thermostat
System Protection If the coolant or the engine oil overheat during operation, certain vehicle functions are influenced to the effect that more energy is available to the engine cooling system.
These measures are divided over two operating modes:
• Component protection - Coolant temperature between 117°C/242°F and 124°C/255°F - Engine oil temperature between 150°C/300°F and 157°C/314°F - Result: The output of the air conditioning system (up to 100%) and of the engine is reduced
• Emergency - Coolant temperature between 125°C/257°F and 129°C/264°F - Engine oil temperature between 158°C/316°F and 163°C/325°F - Result: The power output of the engine is reduced (up to 90%)
“Failing water pumps on BMW around 40k is the norm. My water pump on my e39 fails every 35-40K. A buddy of mine has a M roadster and his fails every 40k. Buddy of mine has an m5... clock work my friend.. every 40k.
Also, what I have found is that ever 80K or so... full overall of the coolant system needs to be done. I have had many BMW mechanics at reputable independent shops all say the same thing.
This is the nature of this beast... you either live with it or get a Honda”
背景材料：BMW N54 直六引擎使用的电子水泵，约十年七万公里发生不可修复损坏。
拆迁单干户来了，拆拆拆！
不可逆拆解，因装配时定子线圈和磁性转子之间有三相接线焊接在一起，然后整体嵌入铸铝腔体后并粘结于外壳固定，拆解时无法整体分离，故暴力拉断三相接线才能一分为二。
定子线圈已经粘结在铸铝腔体内固定，不破坏性拆解无法分离，红圈为三相接线。
生生被拉断，远处模糊可见脆裂的轴套【轴承】
注塑磁性转子表面多处开裂，有明显刮蹭痕迹。
磁性轴套【轴承】脆裂
电子控制部分未见异常，其实除非有显而易见的烧结，好坏是看不出什么名堂的。
水泵不能正常运行大概率与转子开裂和轴套脆裂有关，结合从网上看到的信息，这种物理损坏并不少见，但凡拆解的都提到了转子磨损的问题，至于那个轴套【轴承】不细致观察或彻底拆解很难被发现。
如果是基于非电子控制模块故障所致，估计通过改善材料加工工艺有可能进一步延长水泵的工作寿命。
福利：这个节温器收了！
可由MAP控制的节温器，甩了纯被动式节温器几条街。
左侧只露出一半的应该是check valve，这个阀门的保留还是很传统的。
BMW Data for typical N55 Engine Cooling
The engine control unit regulates the following temperature ranges:
• 108°C/226°F = Economy mode
• 104°C/219°F = Normal mode
• 95°C/203°F = High mode
• 90°C/194°F = High mode and control with characteristic map thermostat
System Protection
If the coolant or the engine oil overheat during operation, certain vehicle functions are influenced to the effect that more energy is available to the engine cooling system.
These measures are divided over two operating modes:
• Component protection
- Coolant temperature between 117°C/242°F and 124°C/255°F
- Engine oil temperature between 150°C/300°F and 157°C/314°F
- Result: The output of the air conditioning system (up to 100%) and of the engine is reduced
• Emergency
- Coolant temperature between 125°C/257°F and 129°C/264°F
- Engine oil temperature between 158°C/316°F and 163°C/325°F
- Result: The power output of the engine is reduced (up to 90%)
更多我的博客文章>>> 宝马电子水泵简略拆解 2007 Range Rover Sport HSE的气动悬挂故障灯亮了。。。然后灭了 苹果本板砖满血复活 在引擎过热的边沿多次试探 常在河边走哪有不湿鞋：小事故两则
“宝马软管，塑料冷却系统部件和水泵的寿命，我认为6-7年或90-105k， 冷却水可能会持续（在某些情况下更长）更长时间。”
“Failing water pumps on BMW around 40k is the norm. My water pump on my e39 fails every 35-40K. A buddy of mine has a M roadster and his fails every 40k.Buddy of mine has an m5... clock work my friend.. every 40k.
Also, what I have found is that ever 80K or so... full overall of the coolant system needs to be done. I have had many BMW mechanics at reputable independent shops all say the same thing.
This is the nature of this beast... you either live with it or get a Honda”
特斯拉官网：与汽油车不同，特斯拉电车不需要传统的换油，燃油滤清器，火花塞更换或排放检查。 作为电车，甚至刹车片更换也很少见，因为再生制动会为电池提供能量，从而大大减少制动器的磨损。
老经验：工厂里的大机器马达，从来无需循环冷却，每个电动机一头就是一个“电风扇”风冷自己。（老经验碰到新问题了）。
弱弱问一句, 直流电动机有3相吗?
3 phase step-less or brush-less motor
三相无级或无刷马达。
其实应该是两组三相，三根线是两组得供电，所以三线<>三相，你的理解也是对的。
維修項目里有一個是換冷卻水
很有参考价值
3-phrase brushless dc motor