Impeller Explosion

So my impeller crapped out this weekend. After I pull the sea-water pump off, I could only recover what looked to be half of it from the housing and the liquid to liquid cooler. This is on a v-drive merc 350 mag. Where did the rest of it go? Will the remainder flush out on its own or is there some way to back flush the system? The holes in the cooler are pencil size so i'm sure that some got through to the next stage, which I believe is the recirc pump. Thanks in advance for your help.
Mike

Just curious, how long had it been since the last time you replaced it?

I've heard littel pieces can get stuck, but watch the temp guage , but I think most of it will flush right thru.

Do you have fresh water cooling, or is the "water to water cooler" you mention the transmission cooler?

Anything that made it through the heat exchanger would propably pass through the rest of the system without trouble. I would recommend taking the hoses off both ends of the heat exchanger and back flushing it to get out any pieces that might block it.

I bought the boat in march. I was told it was changed at the beginning of last year. I have fresh water cooling, so yes I believe that is the transmission cooler. We use a similar cooler with fuel and oil(liquid-2-liquid)on our aircraft so I stole the term.Thanks.

It probably overheated by being starved of water (which keeps it cool) or idling for an extended period of time. Back flush and replace, change every season or two.

I understand what the pump and the heat exchange do. I need to know if the small pieces of the impeller that made it through the heat exhange will damage the engine or just pass thru. If it needs to be backflushed, what is the best way to do it? Thanks again.

Mike

Take the hose off at the transmission cooler and the hose off at the output on the water pump. Flush water through from the tranny cooler side to the water pump side. To ensure this works even better hook up a shop vac on the water pump side and suck the water and impeller parts thru. Then take the hose off that leads from the thermostat to the tranny cooler and flow water down and again use a shop vac to suck from the tranny cooler end. If the boat is in the water take off the imput hose to the water pump and suck with a shop vac or if not in the water flow water from the imput hose and suck with the shop vac on the grate on the bottom of your boat. You may find most parts on this grid. When taking off the imput and output hose on the water pump remember which goes where or you will be replacing your impeller twice. If you continue to have problems check your thermostat as some can get caught in there. Basically follow all your hoses and where ever you can take off a hose do so and flush.

Thanks Rob.