Time for the Water Pump, 2 wrench job...

[Steve Tinker]

Your biggest problem now is the plastic debris lodged in the cooling passageways of the cylinder heads. Some of the passages are small and if they get blocked or even partially obstructed by the remnants of your impeller, it causes localised overheating of the head. Not a good thing!!

Remove the thermostat and see if there is any debris in the housing and try and back flush the cooling system. I don't know how easy that is going to be, use the search function above to get more details. Perhaps JFPinPA, Jake Raby or someone who has already back flushed or cleaned out the cooling system can give you some tips.....

[SpikeJr]

Originally Posted by Steve Tinker

Your biggest problem now is the plastic debris lodged in the cooling passageways of the cylinder heads. Some of the passages are small and if they get blocked or even partially obstructed by the remnants of your impeller, it causes localised overheating of the head. Not a good thing!!

Remove the thermostat and see if there is any debris in the housing and try and back flush the cooling system. I don't know how easy that is going to be, use the search function above to get more details. Perhaps JFPinPA, Jake Raby or someone who has already back flushed or cleaned out the cooling system can give you some tips.....

Well, went back thru some threads on the topic. Found this a few years back:

http://986forum.com/forums/general-discussions/42978-water-pump-impeller-tips-chips-your-cooling-system.html

Nice discussion on the process. Unfortunately, the gent that experience the failure was unsuccessful in finding any extra parts from his impeller despite the labor to back flush the engine. Perhaps they made it through and are lodged in the radiator - maybe they are stuck in the passages. Jake Raby added the commentary that he frequently finds parts of impellers in the passages during the rebuilding process in cracked heads...also the good advice to PM the water pump every 3 years regardless of mileage to prevent this type of failure.

Since I'm past the PM stage - I guess at this point I'm stuck as back flushing doesn't seem to produce good results. I will strain the fluid I collected to see if I can find any chunks. Earlier I think I found some pieces the size of ground pepper...but nothing substantial. After that, I think I might back flush the engine as a hopeful measure...that's about as far as I can go at this point. After that, I'm on borrowed time if the passages are truly clogged...I guess Jake will be in business down the road with me...tough to get my mind around pulling the engine early to find these pieces vs the consequences of not pulling the engine...I would defer to Jake / JFPinPA and the other seasoned wrench turners what they would do after a back flush in this situation...