Water Pump Survey - 986 Forum - The Community for Porsche Boxster & Cayman Owners

gisound · 02-16-2018, 05:47 AM

First post here by the way! Great source of info! My question is....How many of you here have had a water pump failure that resulted in a broken impeller? If you were not able to account for all of the parts even after a back flush did you then suffer head damage afterwards? Just wondering how many of these types of failures result in real life occurrences of damaged engines eventually? Asking for a "friend"

Deserion · 02-16-2018, 07:27 AM

Usually others will recommend changing the pump before it disintegrates, based on time over mileage.

I replaced mine a few years ago when the bearing started to go out, but the impeller was still intact.

gisound · 02-16-2018, 07:57 AM

Thanks Chris. Mine gave little to no warning. Just bought the car a week before. No unusual noises from the car at all. Driving home from work one day sitting in traffic. Engine temp normal (pointer right between the 8 and 0), when suddenly at a red light the engine begins to squeal horrendously (belt squealing sound) for about 4 seconds. I immediate pulled thru the intersection and into the parking lot, shut the car down. Didn't notice any coolant or oil leak no smells. Nothing unusual from what was visible at the time. Started the car back up and all seemed kosher. Drove it about another 5 miles when suddenly the power steering went out - temp started to rise to almost 2/3. Pulld over shut it down and towed it home. Opened the cover- serpentine was trashed and water pump bearing was obviously gone. Took off the pump and 2 large chunks of impeller fell out with it. Flushed and got some of the remaining pieces, but Im sure some are still in there. Anyone with similar experiences? How has your car held up afterward?

thstone · 02-16-2018, 03:43 PM

I've had four engines. Two water pump failures. Both leaked but the impellers were completely intact. Two other water pumps replaced before they had problems as preventive maintenance.

dghii · 02-16-2018, 05:57 PM

I replaced mine a couple of years ago at about 120K miles. Impeller was intact and no wobble to the shaft. I think I could have retorqued and been good to go as just had a small leak from around one of the fasteners.

I helped a buddy do the WP on an 03 with 100K miles....no impeller left, shaft about to wobble out of the pump and serpentine belt shredded. I replace WP and thermostat (and belt of course) and flushed with distilled water twice before refilling with coolant. Been about two years now and he's been good to go.

Geof3 · 02-16-2018, 09:29 PM

I don't think the WP would spontaneously disintegrate without some warning. It has probably happened, but would be rare I believe. I think the usual fluid weeping would occur and let you know the WP was failing. It does seem wise to preemptively change them with reasonable mileage.

MWS · 02-17-2018, 12:02 AM

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 · 02-17-2018, 05:47 AM

Quote:

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 · 02-17-2018, 06:58 AM

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 · 02-17-2018, 09:00 AM

Quote:

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 · 02-17-2018, 06:16 PM

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 · 02-18-2018, 02:44 PM

Quote:

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!

Timco · 02-17-2018, 04:37 AM

I heard a rubbing noise. Saw a line where the shaft had leaked. Stopped driving and swapped it next day. Has rub marks but zero lost pieces. Saved it to show future owners / others. Because it’s composite, no marks on engine at all.

kirkandorules · 02-21-2018, 12:08 PM

My original water pump failed at around 120k miles. The impellers were worn down to almost nothing, but it was the bearing that failed (causing it to start leaking) that prompted me to replace it.

I assume the impellers had just worn over the course of almost 20 years, it didn't look like something that happened at once. I don't think