e39 m54 coolant change

[mac7]

I am planning to do this tomorrow, just read a few diys. The long and the short should I open the drain plug on the block or just open the hoses low on the rad to drain the fluid .thanks

[Lord Vader]

Well kinda late to this thread... But for future reference warm up the car to operating temperature first. This opens the thermostat allowing more coolant to circulate through. Then open the drain plug from the rad and allow that to drain first. I wouldnt bother removing the rad hoses unless your replacing them.

[mac7]

Yea done that an burnt the shit Out of my hand when removing block drain under exhaust manifold .but it was worth it as most of coolant (water in my case) is held there.