Hit Sandbar Overheated

[larman]

So I veered off course and hit a sandbar going about 16 knots. Everything seem ok I was not stuck so I continued my trip. Less than 5 minutes later we overheated our Cummins 6bta starboard engine. When limped home on one engine, when we got back to the dock I took off the raw water intake filter and there was a little sand about 4 ounces. I’m thinking I killed the impeller? Any thing else to check?

 

[High Wire]

Is there a clam shell strainer on the outside of the intake that could be plugged?
Water flow out of the exhaust?
Driveshaft can be turned by hand?

 

[larman]

Clam shell strainer? Do u mean the intake on the bottom of the boat? Got back when it was dark wanted engine to cool before restarting to check water flow. Will check today.

 

[Pete Meisinger]

With one hand on the shut off valve, remove the top of your strainer. You should get a deluge out of it. If you don't there is probably some blockage at the boat bottom.

pete

 

[High Wire]

Clam shell strainer? Do u mean the intake on the bottom of the boat? Got back when it was dark wanted engine to cool before restarting to check water flow. Will check today.

Yes

 

[OldDan1943]

Change the impeller and flush the engine and coolers.
Might consider doing the same for the other engine and generator too. (if the gen was running at the time.)

 

[larman]

With one hand on the shut off valve, remove the top of your strainer. You should get a deluge out of it. If you don't there is probably some blockage at the boat bottom.

pete

Will give that a shot. Both engines are fed thru the same bottom intake so I don’t think it will help but will try.

 

[kchace]

Change the impeller and flush the engine and coolers.
Might consider doing the same for the other engine and generator too. (if the gen was running at the time.)

IMO this is the best advice. With sand in the strainer, you already KNOW you’ve ingested sand into that engine’s cooling system. There could deposits of sand anywhere inside the flow path.

Ken

 

[OldDan1943]

Larman, by "deluge" you mean lots? Depending upon the depth of the hull inlet, the incoming water column will be less than 2 to 3 inches. The water pressure will not be that great. You can hold your hand in the column without fear of damage to your hand.

 

[psneeld]

With one hand on the shut off valve, remove the top of your strainer. You should get a deluge out of it. If you don't there is probably some blockage at the boat bottom.

pete

......depends how high or low in the bilge the strainer is mounted.

My experience with sand is usually it is limited to the strainer or something in the intake....usually not an issue past the strainer...but anything is possible.

 

[OldDan1943]

With one hand on the shut off valve, remove the top of your strainer. You should get a deluge out of it. If you don't there is probably some blockage at the boat bottom.

pete

Or a 'sea creature' build up between the hull valve and strainer.
If that hose is plugged up, I recommend replacing it vs just cleaning it out.

 

[larman]

Good news it was the impeller. Replaced and all is well.

 

[wkearney99]

Did you find the pieces? Because they went somewhere and you don't want blockages...

 

[OldDan1943]

larman, while you are down there, check the impeller on the other engine and the generator.

Yes, gotta find the pieces too.

 

[Frosty]

Just a third voice saying that you want to be able to find and extract all the pieces so you can "re-make" the full impeller, puzzle style, on the workbench. Otherwise they lurk downstream in the cooling system and come back to haunt you.