I flushed mine recently, including the radiator and engine block. Which engine do you have ? Mine's the 4.4 and it was a matter of removing a nut on the radiator plus two from either side of the engine block. However, one of the nuts on the engine block was inaccessible to I could only remove one of them.

So shavings in your coolant ?? Mmm .... I too hope it's only some debris left from switching the pump. When you've drained the rad and block, run loads of fresh water through the system and watch out for any more shavings that might wash through.

I used a standard coolant from the local auto accessories shop (50:50 coolant and battery water), however someone on here mentioned that there was some sort of special coolant to be used which prevents corrosion in the system.

It's not a huge job to be honest.

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2001 X5 4.4i