Water Pump Longevity

[rick3000]

The idea behind the preventative WP replacement is that if it fails, which is more likely the older the pump is, the plastic impeller will break, and the shards can lodge in the radiators reducing their cooling efficiency. That ends up being a bigger problem than $200 for a new pierburg WP every few years. I had mine replaced once under warranty and changed it myself at 90k when I flushed the coolant and installed a third radiator.

[Frodo]

Originally Posted by rick3000

The idea behind the preventative WP replacement is that if it fails, which is more likely the older the pump is, the plastic impeller will break, and the shards can lodge in the radiators reducing their cooling efficiency.

...yup, and, more importantly, my understanding is that those little pieces can lodge in the head, blocking coolant flow and creating local hot spots and heat-related cracks in the cylinder head.

So it's not just a coolant issue, it's an engine integrity threat.

I had my WP go many thousands of miles ago. From the time I saw an occasional drop of coolant leak with an accompanying slight hot coolant smell until the thing (WP) went totally and suddenly and utterly south was not long. Not a lot of lead time to react. Bit the bullet, got her up on jack stands, and changed out the WP and thermostat (and the motor mount while I was there). Before refilling with new coolant, I flushed the hell out of the system and never retrieved a single shard of WP impeller. Fortunately I've had no problems. But apparently those problems do sometimes happen.

Do a search. There's a lot of info on the topic here. Jake Raby, who knows these engines better than maybe anyone and who, unfortunately, no longer provides input to this forum, has in the past talked a lot about this issue.