CTIIpilot

I am sure this has been discussed before, but I couldn't find a thread. I am in the process of replacing my water pump on my 01 C4. I had no issues or water leaking and then heard a ticking sound and got out and looked to see the water pump leaking. I drove the car a mile home and parked it. The temp never got above normal. Unfortunately when I pulled the old pump off the plastic impeller blades (original pump for the car) were broken off. I found two of the blades in the inspection port at the front of the engine, so still missing 4. I am not sure if they came out with the coolant or not when I drained the system. Looking for advice on how to proceed? thanks in advance...

Old pump, with broken blades.

996-CAB

I don't have an answer, but I feel your pain. The dreaded water pump. Arghh. When I replaced the water pump on mine, I discovered it had been previously replaced, so I am on number three.
Could you not look through the drained coolant for other blade bits?

CTIIpilot

Well, I wish I had. I found two more pieces on my garage floor. It wasn't exactly a neat operation when the coolant drained and I had disposed of it before I discovered the old one was damaged. It was the original water pump, so at least that is a positive. I am not sure if this is something that people just keep an eye on the temps and check the inspection port and periodically drain the coolant a couple of times or is a bigger issue that needs to be handled immediately.

gbarron

There is a good coolant drain/flush procedure on this forum that might help you locate more of the missing pieces, follow it precisely and hopefully you recover the remaining bits:

https://rennlist.com/forums/996-foru...pump-tips.html

allcool

The flush link gbarron posted is a great, fast, efficent way to drain the system totally, I've used it many times. I believe with the water pump out the fast flush many on our forum use won't be possible, but could be wrong here.

IIRR Len Hoffman (or maybe it was Charles?) on one of his posts/blogs explained how after a water pump failure/replacement, in about 6-9 months after, most all 996 with a 3.4L experience a cracked head from impeller pieces jammed in small coolant passageways blocking the flow of coolant. He says most all 996 cracked heads can be traced back to failed water pump impeller pieces. He said when rebuilding heads/fixing cracks, when he's flushing out the coolant passages, pieces of water pump impeller come flying out....

So if it were me, I'd call Hoffman, or do some research and see how to correctly flush out these water pump impeller pieces since they are deadly to our 3.4 heads... If you find out how to flush these out please come back here and update this thread as I'd like to know the method to use...

996-CAB

Here is a link to this issue from a couple years ago: ((HELP!!! Water Pump impeller lost all its FIns!!!!)) - Rennlist - Porsche Discussion Forums

hardtailer

Sorry to hear about your troubles.
Please tell us, do you feel any play in the water pump shaft?

If you cannot retrieve all pieces and depending on how you estimate the chance of bits being flushed out when draining the old coolant, it could be prudent to drop the engine and remove the heads to be able to backflush them before cracks develop.
Would save you time and money, considering how experience by Hoffman speaks almost of a certainty that heads will develop cracks after pump blades have broken off.

CTIIpilot

Thanks...yes, there is slight, but noticeable play in the old pump.

Gary12000

What about back flushing against the normal direction of flow, maybe that possible, im sure it would be a pain to do, but the other option is just chancing nothing will go wrong in the future.. im being a bit of a keyboard warrior here, as if its apin i would likely take my chances after a regular flush.