The picture is of two coolant tubes located on the driver's side (LHD) of an M10 engine...this tube came off of an M10/e21 I found at a pick-n-pull near where I live...this car is nearly 100% rust free...but after loosing the head I discovered that electromagnetic current/charges caused the water/coolant to interact with the aluminum heads causing the aluminum heads to corrode internally...rather than blowing a head gasket it corroded from the inside...this corroding also included this coolant tube shown...apparently it is NLA from BMW and as is illustrated the replacement I found is only "ok"...
