Impeller blades missing, an issue?

[Graeme Walker]

I’ve just taken possession of boat with twin Cummins 6BTA 330HP engines. During the seatrial the Cummins rep had a look at the impellers and wouldn’t let us go out without replacing them, the port impeller was very chewed up and missing 4-5 blades. Sea-trial went well and engines go to WOT without issue, no smoke on start, ~700hrs. I asked the rep whether the rubber impeller blades would be an issue as they are now floating around the coolant. His answer was that it’s unlikely they’ll be an issue but to remove/clean the after-coolers during the winter haul-out. Boat has been run twice on one hour trips and need to go on another for ~6hrs. Just wondering if that will be an issue since I’ve heard many horror stories. There is no time or resource available before the trip tomorrow. Any suggestions are welcome. Thanks.

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[Graeme Walker]

Appreciate the comments, will run only at hull speed for now, only went at WOT for seatrial for brief period. I have maintenance plan scheduled for the winter season, it’s getting longer. I’ve been ‘grunting’ my way through your tips, very informative. Thanks.

[Tony Athens]

If you make thru your trip without over heating or blowing a seawater hose from high seawater pressures, your aftercooler needs to go to the bench and serviced per my protocol…….

If it was me, I’d run at hull speed until the entire engines seawater system has been gone thru top to bottom–Now you have a base line to move forward and maintain properly.

Tony

[Rob Schepis]

Impeller is bad but I’ve seen worse. You will have to go fishing for those rubber pcs at some point, the sooner the better. I gather she is running at normal operating temperature at the moment? If so, then okay to use it if you must but I would keep one on your temperature gauges at ALL times. Are the fuel coolers in place or have they been removed? Rubber pcs could be in the fuel cooler or aftercooler or in the other direction – in the intake hose south of the pump. Why not take out the bottom aftercooler zinc – takes a minute and you may get lucky and be able to shopvac or fish out some rubber pcs. Do you by chance have a scope? Here’s a shot of the sea water passages at the bottom of my aftercooler I took the other day when checking zincs. Just a wifi scope on an iPhone..

[Graeme Walker]

I should have mentioned this is a fresh water boat and has been well taken care of except for this single item. Generator impeller also had to be replaced, I suspect because previous owner put very few hours on engines over the past 10 years. Thanks.

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