- Re broken plastic pieces...I guess you can use a small vacuum to suck it out.

- Or use a garden hose and flush it.

- Re WP: I have been happy with HEPU, the HEPU in my 1998 528i was installed in May 2006 at 90K, it is now at 185K and still fine, I plan to replace it soon.

- Plastic impeller was used to save weight by BMW, but used in the "wrong" place. This is not a place to put plastic in there.

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1998 E39 528i 5sp MT
2006 E53 X5 3.0 6sp MT