Has anyone ever run across a situation where a water pump has ended up with reduced pumping capacity due to the vanes becoming worn down from erosion (not corrosion) at high mileage? My water pump is original with almost 325,000 miles – believe it or not!

I am starting to suspect that the pump may not be displacing as much water as it should, but I don’t want to pull the pump just to inspect it; if I can rule out this possibility, it could save me some potentially unnecessary work. (I was thinking about replacing the pump just as a matter of course, but it’s not leaking – and I’m thinking about the old adage “if it ain’t broke, don’t fix it”.)

Thanks!

Glenn

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Current rolling stock:
2001 E55 183,000+ Newest member of the fleet.
2002 E320 83,000 - The "cream-puff"!
1992 500E 217,000+
1995 E300D 412,000+
1998 E300D 155,000+
2001 E320 227,000+
2001 E320 Wagon, 177,000+

Prior MBZ’s:
1952 220 Cab A
1966 300SE
1971 280SE
1973 350SLC (euro)
1980 450SLC
1980 450SLC (#2)
1978 450SLC 5.0
1984 300D ~243,000 & fondly remembered
1993 500E - sorely missed.
1975 VW Scirocco w/ slightly de-tuned Super-Vee engine - Sold after 30+ years.