2006 Avalanche

[Anson 0]

I bought an 06 Avalanche with a Black Scorpion 6.2 with really low time (230hrs) that looked like it had been taken care of, but it wasn’t.  The latest issue is, the sea pump will not pump.  After destroying a couple of impellers I finally checked the cooling lines and found an insane amount of broken impeller pieces in the tranny cooler. The boat had a new impeller in it (should have been a red flag) so I have no idea if more material is downstream or if anything can even get downstream. My question is can anything actually get passed the tranny cooler?  I can now push water with a garden hose from the pump all the through the exhaust, so I’m wondering if I’m ok or I need to check the thermostat housing? Also, giving up on the original sea pump and replacing with a Harding SS.  Sorry for the really dumb questions, but I cant find anyone in Arizona in the boat business that has an IQ greater than a pine cone. The previous owner is completely worthless, not sure how he managed to get it off the trailer.

[Troy 234]

Wow an Avy with the 6.2, awesome. 

I would try and backflow the best you can to clean the tranny cooler out and go from there. Sorry I can't answer any other questions. I have never had the impeller come apart on mine. I change every 2 years and never had an issue. 

[InfinitySurf 302]

Since you can push water thru to exhaust now, it sounds likely that you got the issue cleared. Like Troy said, pushing water thru and then back-flowing the system is the method I have heard of to clear all debris. I think personally what I would do after backflow to see if any debris comes out backwards....is I would then pull all the plugs and drain the water....and see if any debris comes out of the plugs or any passages get blocked with any debris (I put a shop vac nozzle at each drain location to suck out every bit of water possible and figure that also increases my chances of pulling out any debris doing it that way. I would also pull the thermostat to make sure there is no fine debris that may be plugging/blocking anything as well as put it in boiling water to make sure it works properly. Also flush and back-flush those lines with thermostat out.

I have not had an impeller shred on me either since I replace every year (tho think I am gonna run mine from 2018 another season since its in perfect shape and I remove when I winterize so it does "take a set" as I keep the old ones as spares. Even tho I got 250-300hrs surfing last summer, because I have a group of friends where we all ride/surf together and trade off boats each week, we all only put like 80hrs each on our boats). I THINK if anything was small enough to get past the trans cooler, then it should get spit out of the exhaust, but draining would be my thought on how to double check that theory.