Engine replacement issue. Water pump impeller chewed up...where'd

[Byron in Atlanta]

Hello all...I am in the process of installing my new/used engine after throwing the rod in August. I was thinking that I would reuse the water pump from my blown engine as it only had a couple of thousand miles on it. When I removed it, the impeller was chewed completely up. It seems that when the engine blew, metal pieces from the engine case, rods or pistons entered the water channels and destroyed the pump. Any suggestions on how to clean out the cooling system short of removing everything?

[JFP in PA]

Actually, I'd go the other way around; your water pump may have came apart (on the track, if memory serves), and the bits blocked some of the water passages to your head and more importantly, the oil cooler area, and that is probably what started the fatal chain of events leading to your rod failure. Not that uncommon, this is why Jake is suggesting changing out the water pump every three years, even if it is working fine...........

Getting all the bits out is a major pain, probably will require total disassembly unless you are very lucky.

[RFM]

+1, that's exactly what i think also.

[Beelzy]

+2.....The impellar blew up, pieces went into coolant ports and blocked enough of them to blow the engine.