Water pump woes: Plastic impeller cuts through aluminum housing!

[Timbert]

Sprung a leak on the inherited A4 Avant AEB (completely external water pump) but before ordering the front half of the pump I took a look to see exactly where it was leaking. Never seen anything like this before, as the impeller worked its way partly off the shaft and was rotating into the housing, slowly cutting its way through, and I do mean through! No idea how long it was happening, I didn't notice any strange noises, but this is what I found when I finally got the thing out. 150k miles and not sure if it's the original pump but it's OEM Audi stamped "Made in Germany" although the impeller says "Italy" on it.

I’ll also bet the massive amount of rust in the coolant provided a nice amount of abrasion, as this could only happen over some time. The impeller is still firmly mounted to the shaft, and equally worn, although it slid partly toward the housing. I have flushed the system a dozen times with water and some Prestone flush, but certainly expect aluminum shavings got jammed throughout the radiator.

The new unit is a $56 Beck Arnley 131-2317 from Amazon, includes the housing. The finish was ugly and there were plenty of casting marks inside and outside.

[a4kamila6]

Aint that some shit. You the man