Water pump question

The water pump on my '03 c4s died - bearing seized up and composite impeller was damaged - there are some missing impeller pieces that I cannot find after removing the water pump - they are no larger than 0.3x0.1 inch - see attached photos - I have done a bunch of searching and reading and have found everything from it won't be a problem to it will get lodged in a head cooling channel resulting in a local hot spot, warped head, coolant in oil, $15k new engine. It does not appear a cooling system flush is an easy thing and may not result in getting any pieces out of the system - so do I try and flush or put it back together and cross my fingers? Any advice is appreciated.

Have you removed the thermostat and look there?

That's a mighty big dilemma you have there my friend. Those are some big chunks missing from the impeller. Do as Ahsai said, remove the thermostat and check there. You will need to backflush the coolant system and filter the exit point with some cheesecloth. I would start at the front with one of the radiators. However, that being said, and perhaps done...FACT - impeller pieces can get lodged in the small passage ways in the heads creating localized hot spots and that will lead to premature failure of your engine. You could gamble and not do anything other than a flush and go. I am sorry, but if it were mine I would get it taken care of properly (heads removed, total flush job, etc.). It seems the expense to do that would negate the nightmares of never knowing exactly what is going on with the engine. It's the price we pay to play.

Back Flush the system multiple times! I went to Menards and got two garden hose attachments that are used to blow out a stuck drain. They come in a package... They get pressurized and swell up for a friction fit. A small opening at the far end fill and pressurize what ever they are stuck into. I flushed from all angles and openings on the motor end and was able to catch in the back flo some of the impeller pieces. I had a huge smile on my face when I found the missing pieces from my impeller.

hi guys - thanks for the replies - the photo makes the missing pieces look larger that they are - i also dont know if the broke off as a single piece or multiple smaller pieces - car has almost 90K miles on it - going out to remove thermostat housing and have a look, though i have taken the hose off and looked/felt around and did not see any - i dont know if flushing really works or if i am going to make a bigger problem - i fear the pieces may be lodged already and wont move - joe what opening were you able to flush pieces out from - this is really bad but do i just put it back together and drive it or possibly trade at the dealer for 997 - this is terrible

I pressurized and flushed from the T housing and from the water pump... I would flush from one hole then drain and collect all the water looking for bits of impeller, then the next hole and repeat till my arms got tired. Remember that after you do this you need to refill the system with the proper coolant and burping procedure!

I would do like Ahsai said and look in the area of the T-stat, when mine went all the pieces were right there, not too many other places for them to go.

any chance they came out when you removed the pump?

Good morning everyone - I removed the thermostat housing and found two large and two small impeller pieces, good news - bad news stil two smaller pieces I can't find - I think I am going to put it back together and hope I don't have a problem.... - waterpump and thermostat factory metal gaskets go on dry, correct?

Quotes source post: 11989866

man, I have to admit that you have way more guts than I do. Hope your gamble goes well.

This is what I used to try to flush out my system... They had a two pack... Worked great... Slid it into an opening and slowly turn on the hose, it swells up and forces water into the opening... I flushed back and forth a few times into any opening I could get to force any debris lose... Then I filled the system with water and ran it for a little bit and then dropped the T stat and water pump again just to make sure I was flushing it out as much as possible! http://www.menards.com/main/mobile/p...810-c-6122.htm

thanks for the help - so i am scared to put it back together - going to sit and drink coffee and watch is snow here for a while to decide if i am bold enough to skip trying to flush.....

Quotes source post: 11990150

Up to you of course, but you really should do the back flush. Back flush both the engine and the radiators. The debris will not be that firmly lodged and a good back flush will have the stuff out. The operation doesn't take that much extra time and effort and for peace of mind I think it is well worth it. If you want some further incentive go price a replacement engine or get a quote on your car as a roller should the engine suffer a failure from the bits blocking the coolant flow then tell me you'd rather "save" an hour or two of labor by skipping the back flush and risk the money (and time) a serious engine problem, possibly even a fatal engine problem, would cost you if there is some debris left in the engine and at a critical spot in the engine's cooling system.

Flush flush dear lord it's already apart.. Flush it until you recover them. I understand the hesitation on doing the work but man that would suck.. Especially if you trade it in... Car kharma..

Quotes source post: 11990150

https://rennlist.com/forums/996-foru...sing-help.html I'm currently in the situation. I hooked up a garden hose the the hose that comes off the thermostat and its now running clean water. Scurrilous how your scenario played out. Need to know what else I should do to prevent a problem. Thanks

This is why water pumps must be replace proactively... Being able to retrieve the impeller pieces after a failure is not something where the odds are stacked in your favor.

I know its been answered before, but i forget. Are we replacing the water pump with plastic impeller or metal impeller. I think its been stated that if one uses the metal impeller and it fails it may damage the engine case and cause major probem.

Quotes source post: 14279139

Correct! Not flushing isn't being bold, it's just foolish!