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!

So I assume the red letter box is the new genuine Porsche water pump? Yes there are OEM manufacturers that are not genuine Porsche which can be confusing. Another example is Pieburg...something like that anyway

I remember catching some chatter on another forum indicating that Lasos fail early

Thanks Jager for clarifying on the brand of the waterpump that failed so rapidly. While we will never know whether the Porsche part would have lasted longer or not, I am certainly planning on replacing mine with the factory part when the time comes. And yes, I have decided that I will not replace the pump until there are signs of failure, in spite of the urgings of some others.

In the interim, I am careful not to open the coolant expansion tank when the engine is warm as per Pedro's advice. When I replaced my serpentine belt this spring, I checked out the pump for signs of leakage or play in the pulley and all seemed good. There is also no discernible bearing noise when it is running. I also decided not to replace the lifetime coolant as, it strikes me that if there is a problem with the bleed, I am more apt to cause an impeller failure than if I leave well enough alone. When (or perhaps if considering Pedro's waterpump life) I need to replace the pump, then I will have the system flushed and the coolant replaced. I am also holding off on replacing the thermostat with a 160 degree unit for the same reason. Until then, I am leaving well enough alone.

It might be interesting to see if those who suffered early pump failure had previously had the system flushed and coolant replaced, or had required replacement of the coolant expansion tank, or had replaced the thermostat, or had been opening the coolant expansion tank when the engine was hot. Furthermore, if the system had previously been bled, what method was used.

Brad

Just got hold of my new pump.

I find the drag on the pump bearing quite high. You can hear as you spin it and it does not spin for very long maybe two revs before it stops.

Is this normal?

The LASO I put in failed within 30K miles. It blew apart. I replaced it with a factory part. There were clear differences in machining quality. I also used the Airlift tool and after filling have never had to do any extra bleeding. Fast and precise, I would recommend nothing else.

failed laso:

http://986forum.com/forums/uploads01...1368662205.jpg
http://986forum.com/forums/uploads01/wp21368662243.jpg

comparison:
http://986forum.com/forums/uploads01/wp31368662414.jpg

I now have the bleed valve open for a couple days... Do I close it hot or cold? Do I remove the reservoir cap to burp the system again while it is hot (per the Bentley manual) before closing the bleed valve?

Wow! Didn't the pump make some noise before blowing-apart?

Jager, for my two cents I would not open the reservoir while it is hot. Before I bought my uvIew Airlift 550000 for the vacuum bleed I did several flushes using just distilled water. Anytime I tried to open the reservoir there was venting. Even with the purge valve open. I'd recommend letting it cool. Doesn't have to be completely cool, but can't be at operating temperature.

If you are in Southern CA, you are welcome to stop by and use my vacuum system. After my first fill, and running the motor, I let it cool down and created a vacuum again and added another 1/2 gallon using the system. Since then it has been running at normal temps. I seriously recommend buying a vacuum system for the coolant flush or water pump replacement as it works very well and eliminates the need to bleed the system.

Thanks Paul... Me too.

Thanks... I will run it for a couple days, wait for it to cool-down, then close the valve.
Thanks for the offer... I think I am in Southern CA? But they call this the "Central Coast", I'm in Santa Barbara county.

What sort of noises and symptoms indicate the pump failing.

Reason I ask is because I hear a bit of a rattle when idling that I think is new and my guess would be the pump bearings or the timing chains.

It even does it when hot so thats probably less likely the timing chains?

Would I see coolant loss over time if its the pump bearings?

My car has ~65K miles on it and still on the 1st pump I think.

Anyone have comments on this?

Jager,

That would be quite a drive to Palm Desert, CA. But if you need it let me know and I'll mail it to you.

Take a look at my thread describing my symptoms prior to the failure. Maybe that will help ...

http://986forum.com/forums/general-discussions/45036-example-how-water-pump-failed.html

The pump has a lot of drag. Even the new one I installed will not spin for long. But it should feel smooth with no side to side interaction/drag. Mine was off center and was slowly scoring the top bolt. You could see it when the engine shield was removed.

jaykay - I'm pretty sure the OEM pump had a bit of drag but was smooth and tight. It did not spin much at all after you let go. As long as you don't hear any scraping or irregular sounds you should be good.

As far as sounds when mine blew up, I had my head under the car earlier that day or the day before and heard nothing too strange. While driving I heard an intermittent squeak/squeal/chirp that I attributed to the Ferrari 308 in front of me. I'm not sure if that was me or not but but 10 or so miles later there was steam coming out the back and at low speeds it sounded like a bag of rocks being shuffled around.

And as far as leaking, the coolant tank had not lost any fluid in nearly 2 years. So it was not dripping any coolant before it failed either.

-Greg

Thanks for the info! The pump I have has the part number 996 106 101 where as others have 996 106 011 56. Is one an older version?

My original pump started having grinding noise (at ~202,000 miles) and then started to leak a little, leaving a spot on the garage floor, and I replaced it with a LASO. The LASO pump starting to fail (after 40,000 miles) did not leak but is started to make noise that I can best describe as one of those old crank sirens (not as loud) being turned at a slower speed and increasing pitch as the RPMs increased.

Most of the advice about refilling the system is based on doing it quickly and getting the car on it's way.

If you have the time.....

I've had excellent results with just filling the system with the vent open then starting the motor with the cap loose and adding coolant as it warms up to keep the tank full. Once the level stabilizes, I bring the tank up to the full line and close the cap and vent and let the car idle until the radiator fans run. Then I let it cool over night. In the morning if the tank is not completely empty, I just top it off and it's good to go.

If it's empty, I repeat the process.