Replacing the Jägermobile Water Pump Again!
 

What is going on? I replaced the original water pump when the odometer broke the 200,000 mile mark, now I am replacing that water pump after 40,000 miles? The replacement pump was Porsche OEM… What happened to quality control on Porsche water pumps?

What a rip off. I am guessing you next one will last 20 K or maybe a Gazillion miles!

It might be production quality, it might not. Three things will drastically shorten the life of a water pump and one is quite common.

1. Corrosive coolant

2. Too much pulley tension

3. An air bubble trapped in the WP causing it to fail to prime and score the shaft seal.

First of all glad you made it to 200,000. I'm also on my third water pump at 120,000 miles. For some reason these motors seem to be hard on the pumps. I stopped wasting money on the OEM parts, after years of buying into them. I now feel most of the time its a great sales tactic and provides a false sense of security thinking you are getting a better part. The pump isn't hard to change and only takes a couple of hours, just make sure you don't put the key in the ignition while you have the passenger seat removed or you will trigger the airbag light. A small swivel socket attachment really helps too! First time I changed the pump I bought into the whole Porsche coolant idea at $50 a gallon, only to watch my expensive coolant run down the street when it blew again. I bought my last pump at Autozone for $150 with a lifetime warranty, That way I don't have to pay for it again when it goes out next time. I wouldn't waste my money on the $50 a gallon Porsche lifetime coolant. Just get a compatible coolant and change it every 5 years, chances are the water pump will go out before then anyways. Make sure you open the coolant vent and drive around a few days to let the gas bubbles vent out. Then close it and top it off. Pump and coolant should probably just be put on the maintenance service list every 40,000 miles.

I use only Porsche coolant, same belt/size and tension pulley, and I always bleed the coolant system if I performed work on the system.

No leak this time, just noisy, the bearings are going out.

Jager - I hear you...
I replaced my perfectly good water pump in 2010 (45,000 miles or so) with a genuine Porsche item bought from Flat6 when eveyone was advocating changing out the W/P every 3-4 years. Within 12 months (less than 3,000 miles) it started leaking. Coolant loss is about a half a cupfull every 2,000 miles, so I've just left it in place, but you must wonder how many genuine Porsche pumps fail before 50,000 miles.
Perhaps its a new Porsche built-in fault, making owners replace the pump before the vanes break off and get stuck in the cylinder head water galleries....:confused:

I just replaced mine a weeek ago. There was a really strong smell of coolant on the drive home. i just chalked it up to the job being recently done. Today i checked the trunk and the coolant wasnt visible unless i peeled back the trunk carpet. A good four inches below the minimum hash mark. Whats up with that? Thats some air bubble...

Pedro on Pedro's board has over 200,000 miles on his original pump and he believes that some of the early pump failures are due to people occasionally opening the coolant reservoir cap when the engine is still hot. It is, of course, supposed to be a sealed coolant system and he believes that bubbling when the cap is removed can lead to air locks (as well as reduced coolant due to vapour) that ultimately cause failure of the impeller. His rule is to never remove the cap; if coolant is down, there is already an issue.

Brad

My mechanic said the failure rate on OEM replacement pumps is over 10%. Not cool.

Good to know.
Pedro also pointed out that flushing the coolant needs to be done precisely, if any air is in the system the original and probably brittle coolant tank with split within a year or so.
Might have been coincidence but that's exactly what happened to me. I ended up spending $1,000 on the flush and new tank within 12 months of each other, I probably should have done the watermpump then too.

Is everyone vacum bleeding their cooling systems after pump changes? Without vacum system bleeding you can spend a whole day burping the system ...and you are never really sure that you have managed get rid of all air bubbles. Air in the system would be a potential cavitation mechanism. If this cavitation occurs near the impeller blades of the pump it can cause failure of the blade. Cavitation can cause failures of impellers even if they are metal.

It is my guess that cyclic stresses from pump cavitation are giving rise to pump impeller blade failures. In addition to this you have age related weakening of the composite material as noted by J. Raby at flat six

If pump your has failed you may be eligible for a free replacement as far I have heard. I only see evidence of seepage on mine so this won't be enough to get a free one. I have an OEM one ready to go in, hopefully it won't let me down....oh yes make sure you change the coolant tank res. cap

I did. I bought the uView 550000 Airlift system to perform the bleed. Worked fine. So far no issues other than a ballast on my drivers side fan needs to be replaced.

I've burped the cooling system several times with no problems. I followed the directions on Pedro's board, then, with a gallon of coolant, I drove around gently with the bleeder valve open, going up and down a parking lot ramp, to slosh everything around. Had to add about a half gallon after that and its been perfect ever since.

Interesting, Wayne recommends a coolant flush every two years in "101 Projects for you Boxster" and advocates using additives. I've done neither.

A lot of people confuse "burping" air manually out of the cooling system by just running the engine for a few miles, which is incorrect.
Ridding the closed system of unwanted air pockets require several heat cycles with the vent valve lifted open. The engine must reach normal operating temp with the thermostat fully open, and then let the coolant cool to ambient temp. This "cycle" must be repeated at least 3 times (still with the vent valve open) to rid the system of air, with topping off the level of the coolant as required.

Here is a picture of the water pump I removed today. It was not leaking and no impeller damage but the thing was making some noise (bearings are bad). I spent about 2 hours bleeding the system, after installing the new pump, per the Bentley manual instructions (three cycles of burping and topping-off). Should I do more?

http://986forum.com/forums/uploads01...1368499809.jpg

Just do the obvious, keep an eye on the tank level for a while.
Are you certain that the water pump you took out is OEM? Just asking, since I bought a LASO pump a few years ago because it was less expensive, but I never installed it because I heard that they didn't hold up very well. The picture of the one you took out looks just like it including the brown impeller. There is no part number on the back side of the casting next to the hose connection. Does it have a LASO casting mark on the front side? The OEM one that I got from Sunset Porsche had the cast in place part numbers on the backside, a black impeller, and the finish was smoother on the overall casting also.

Jager....
If you bled the system as per the book, just keep the bleed valve flipped open for a couple of days of normal driving - the heating / cooling cycles should get rid of any small air pockets trapped in the system.
As Spinnaker says, just keep an eye on the level.

Well, I thought it was OEM but I just got a lesson on water pumps. I took a closer look at the pump I removed and surprise LASO. So this experience supports the theory the LASO water pumps DO NOT LAST. At least I know the pump I just installed is Porsche, I drove down to the Santa Barbara Porsche dealership and purchased from the parts counter.

So I must retract the comment I made on the original post about the quality control at Porsche… sorry… my bad.

Bad Water Pump
http://986forum.com/forums/uploads01...1368583135.jpg
Bad Water Pump
http://986forum.com/forums/uploads01...1368583197.jpg
Bad, Bad, Water Pump
http://986forum.com/forums/uploads01...1368583216.jpg

The box my new pump was packaged in
http://986forum.com/forums/uploads01...1368583266.jpg

Hope this one lasts until at least 300K!