Water Pump Survey

[MWS]

Mine failed about 4 years ago (at apx 30k) with massive impeller failure requiring flushing and more flushing. Pre-failure there were no obvious signs (leaking, noise, etc.), seconds after failure my first thought was IMS...thankfully I was wrong. Still not a cheap repair though...

I guess you could argue that my pump didn't fail, my impeller did. Lol.

[Boxstard]

Originally Posted by MWS

Mine failed about 4 years ago (at apx 30k) with massive impeller failure requiring flushing and more flushing. Pre-failure there were no obvious signs (leaking, noise, etc.), seconds after failure my first thought was IMS...thankfully I was wrong. Still not a cheap repair though...

I guess you could argue that my pump didn't fail, my impeller did. Lol.

Usually bearing fails then the shaft gets wobbly so that the impeller interferes to aluminum casing to destruct itself. And the bearing could fail on its own or due to leaky mechanical seal that allows coolant reaching to the bearing and washing out grease.

With your failed pump, was it just the impeller disintegrated from tight and straight bearing shaft?

[Frodo]

Had my WP go about 7 years ago, at about 58K miles---before I was aware that WP failures were a fairly common occurrence with these cars. For a day or two prior to the failure I thought I had noticed a "warm" smell that I should have recognized as coolant. There was no readily noticeable leakage (ie nothing on the garage floor), just enough to smell as it heated up on the engine surface. Then, suddenly, a clatter as the impeller blades came in contact with the block.

When I got the pump out and could see the damage, I'd estimate (IIRC) maybe 25% of the impeller blade surface area was missing. I flushed and flushed and flushed, placing a wire mesh colander under there to filter out anything that came out. I never saw even the tiniest amount of plastic, so I gave up. Put the new WP in, along with a new thermostat, serp belt and ("while I was there") motor mount. That was almost 40k miles ago---no cracked head problems to date, so I'm thinkin I'm safe.

As an aside, I talked with the head technician at Steinel's Autowerk's, a local place that does a LOT of P-car work. He said that in such a case several years before my WP failure they'd done the same thing (back-flushing) with the same result. He said they don't even bother flushing them anymore, and have had no issues. Not to say it couldn't potentially be a problem in some cases, but an interesting observation from someone at a place that has done LOTS of WPs.

[MWS]

Originally Posted by Boxstard

With your failed pump, was it just the impeller disintegrated from tight and straight bearing shaft?

Honestly, I don't know...I had Porsche repair and I didn't ask the specifics. I'd assume that the bearing (or seal, etc) failed leading to misalignment of the impeller, but again I don't know for sure. I stated that "my impeller failed, not my pump" to be funny, and actually it's probably somewhat true...the impeller exploded and the mechanical portion of the pump was still grinding happily away.

[j.fro]

I'm just finishing getting a 3.4 back together after a cracked head that I know came from a water pump failure/ clog due to impeller pieces. I did engine removal, disassemble. Hoffman machine repaired the heads and ported them. Some PCA friends have helped to get it back together and into the car. It's still cost me at least $4K. It's pretty stunning how much the "while you are in there" costs add up... Clutch, AOS, coils, plugs, chain ramps, variocam pads, different $hit that breaks along the way....

[Frodo]

Originally Posted by j.fro

I'm just finishing getting a 3.4 back together after a cracked head that I know came from a water pump failure/ clog due to impeller pieces. I did engine removal, disassemble. Hoffman machine repaired the heads and ported them. Some PCA friends have helped to get it back together and into the car. It's still cost me at least $4K. It's pretty stunning how much the "while you are in there" costs add up... Clutch, AOS, coils, plugs, chain ramps, variocam pads, different $hit that breaks along the way....

Like I said, apparently it happens. (JRaby certainly drilled that bit of reality into us!) It just didn't happen to me!

[Pdwight]

We have a room downstairs I started "Putting a floor in". This room has been used for general storage ( you know....put in room and close door quickly....run away), it is a large room by modern home standards at just over 18 feet long. I thought I will move both my shops (electronics and reloading ) into this room after I get the floating floor in. That was 4 months ago and over 2 grand later I am still adding outlets and extra ground fault outlets (18 so far), the floor was the easiest part... re walled and reinforced walk in closet...6 gallons paint.....100 feet of trim.......the thought process " well while I am at I might as well....." can cost you dearly.

[Brian in Tucson]

I'm in the process of finishing up switching out an 02 engine (base) into my 01 (base) and the "while I have it out" costs DO add up. Just normal stuff like coolant hoses, plugs & tubes, water pump, serpentine belt, engine mount, spin on oil filter fitting, & UDP. And oil, coolant/distilled water, hose clamps, filters, and auto trans oil, gasket, and filter. Then, of course, I had to switch one of the v-cam solenoids from the old engine to the replacement--sheared wires. Once it's back on the road, I'm thinking that a water pump and an engine mount will become part of the 60,000 service. Doesn't pay to wait for things to break.

As much hardwater calcium carbonate as I found in the old engine, I've already started to save for a set of radiators.

On both of the engines, the water pumps showed no sign of failure.

Still, it seems strange to recycle a "perfectly good" water pump. They are inexpensive enough to replace and throw away, tho.

Oh, and I just bought $600+ in floor paint and have to rent a grinder for the concrete floor in my carport. Brake cleaner works great for getting up oil drips.