:iagree: Cavitation due to poor impeller geometry easily contributes to erosion, over heating and vane failures. That's why I'll never use stamped steel impeller pumps in my vehicles.

2002 X5 3.0 318,200 miles
2014 428i 26,000 miles

2004 325i sold at 123,600 miles
2001 325i sold at 66,000 miles

1970 Firebird - Under restoration (With a cast steel impeller WP)