knfeparty

Had non-ferrous metal flakes showing up in the coolant expansion tank. Almost like a powder it was so fine. Flushed the coolant and saw a good amount of it suspended in the coolant. No other symptoms- no leaks or noises, no overheating.

The car had a Laso pump with composite impeller installed about 20 months ago. I ordered another one just like it through Pelican and they agreed to warranty the original one upon return. Their customer service was top-notch as usual.

Anyways I removed the pump and the bearing felt fine with no play. However, two of the fins showed evidence of just barely skimming the block. I wiped down the block, replaced the gasket, and installed a new pump. Now I'm going to flush out some more coolant and drive more to see how it goes.

mdistel

What year and model is this?

7 Summits

I recently replaced the thermostat and pump a few months ago with a Laso pump. 09 GTS. I will check the coolant expansion tank.

hahnmgh63

Getting ready to do the Serpentine belt and pulleys and also ordered a OEM Laso pump with composite impellers.

Dilberto

I'd always go with the OEM Porsche pumps with the alloy impellers....they are good for 80k+.

hahnmgh63

The one I received from Porsche yesterday, in a Porsche box is the LASO pump on close inspection. The parts guy told me he thought it was a Laso when I ordered it so I posted that above and sure enough it is. Looks exactly like the impellers above. I could have went with an aftermarket Graf (Italy) or GEBA (Germany) with metal impellers. Everywhere I read is the one that was installed was a Composite impeller pump so it was probably a LASO pump back in the day too.

Petza914

Do not use a pump with a metal impeller. Once the bearing wears and the belt tension creates some angle on the impeller shaft, that metal impeller becomes a milling machine into your block, doing permanent damage. Buy pumps with the plastic impellers and change them at about 50,000 miles as part of a PM schedule.

ScootCherHienie

Having to replace something as basic as a water pump at 50K miles is stupid. Where is the "German engineering" on this item? I have a BMW with 143K on it's original factory water pump (not that I think BMW makes great enignes... they have their problems too). Which series of Cayenne and which engines have this concern? 955, 957, 958? all V-8? V-6? Diesel? Turbos, non-Turbos, or both?

7 Summits

I only replaced mine at 100k miles because I needed a new thermostat. Easier to replace both while you have it out. Also replaced the thermostat collar with a aluminum version that won't crack. No signs of failure or wear on the OEM pump but I kept it just in case my laso pump ****s the bed down the road.

ScootCherHienie

Replacing a water pump at 90K or 100K is reasonable... common recommendation for many vehicles to keep from having leaks or sudden failures in the future. 90K-100K often matches the replacement interval for "rubber" timing belts also (if the engine has one of those rather than a timing chain).

hahnmgh63

I'm doing mine here at 89K on my '06CTTS. I'm only doing it because it hasn't been done yet and I'm in need of a new accessory belt so I'm doing the pulleys/bearings and all. Cleaning my Intercoolers, new MAF's & Diverter valves. Also going to attempt new front O2 sensors while I'm there.

knfeparty

This was an 04 Cayenne Turbo. The pump was only 20 months old, figure 20k miles. Just a casting defect in the impeller or a bad bearing; defects do happen every now and then. I also drive the Cayenne pretty hard, off-roading and doing some "spirited" high-rpm driving.

The expansion tank pic makes it look worse than it was. The aluminum flakes were neutrally buoyant in the coolant and for whatever reason all collected in the expansion tank. When I drained the coolant there really wasn't that much suspended in it.

I am pretty sure the LASO is equivalent to the Porsche one. This failure is the very reason to use composite over metal impellers though. Had I experienced the same failure with a metal impeller, my block would be totally trashed. I'm honestly surprised the composite impeller was hard enough to make as many metal flakes as it did, but I think once the blades picked up a few particles of metal, the metal-on-metal contact made it cut worse.

Never experienced any strange sounds or overheating. Going to run the new pump a few hundred miles and check the expansion tank again.

RT_955TT_KY

Just curious, but when you did the water pump was a complete coolant flush performed? I believe in 04 Porsche specified a silicate free coolant G12 or G12+ . G13 is frequently used for top offs or refills and contains silicate. I had the same or similar "dusting" in my coolant when I recently flushed out for G12+ replacement and determined it was most likely suspended silica from the introduction of G13 into a G12 system.

JAGMAN1

I think the LASO pump is junk. My original failed at 90K. Installed a LASO. It lasted 10k and failed. After that experience I used a Porsche pump. 45k on that pump and counting.

hahnmgh63

The OEM Porsche pump I just got from the dealer, in the Porsche box, is a Laso pump. That doesn't mean they've always used Laso pumps but the one I just received is a Laso pump.