ok, I removed the pump today, pretty easy... opened it to inspect the impeller and found that two wings are missing. I'm was terrified where they could have gone so I started looking thru the hose going to the engine. One fell out when I started bending it but one is completely missing....
Has anyone experienced anything like this and should I get the expert to take the whole thing apart looking for the second blade ?
I'm also wanting a new pump for it, the one I have has some rust on the bolts and the shaft so I'm going for a new and keeping this as a spare. I found the one I need and there are a variety of models but a replacement for the exact same thing if $160... not bad..
I'd really appreciate some feedback on the blade, its making me really nervous.
It should indeed make you nervous, but it's not the kind of thing you can't do yourself. First thing is to completely remove the hose from the raw water pump to the heat exchanger, and straighten it out and look through it, to see if there is any chance it got stuck sideways in there. That's the most likely thing in my opinion, and is an easy fix - just get yourself a new hose. If not that, then check your exchanger. If you do replace the hose, make sure you ziptie it out in such a way that the belts won't abrade against it.
Adamtroyg gives good advice - if you're just looking to see if you've got a blade stuck in your heat exchanger, you can take the front plate off, should be pretty easy. If you don't see the blade in there, keep looking downstream, which should mean a smaller hose between your exchanger and your mixing elbow.
If the blade part was able to pass through that hose into the elbow, then chances are it passed all the way through the elbow (which has a wider cross section than the hose) and through the muffler and out the boat, so I wouldn't worry past that. You just want to make sure your heat exchanger is clear of debris.
My experience with impeller wings on these pumps is they have a tendency to tear in two locations, one right by the bulb and one down at the base. If you can't find the wing in those two places mentioned above, then it's likely it tore into small enough pieces to pass through your whole system. That or it's floating in your muffler, upstream of the baffle, which probably isn't any harm so don't worry about it. Screwing around with your muffler can be a big PITA, as they tend to break if you push/pull on them too hard while you're trying to hose clamp them. (personal experience, ugh, I hate mufflers)
I realize you may be a little freaked out about this experience, but it's happened to plenty of us, and in the end it's just incentive to check the impeller once a season. And now that you know how to fix it, you can troubleshoot similar problems in the future should they arise, which is an important skill for a sailboater. I can't tell you how many major malfunctions I've fixed while on the hook. It's part of the fun.