Impeller replacement

Sorry, sitting on the head reading this and don’t have the ambition to read the whole thing. I know your impeller is junk. That’s obvious. But why? Could it be from lack of flow to it? I admit I am not familiar with your outdrive, however, I have seen outdrives that had the hose clamp on the drive water pickup hose come off. The engine would run cool all day long until you got up on a plane and the drive/hose came out of the water and it just sucked air. My 2 cents. Might not help you but might help someone else down the road. Good luck.
 
Riptide III said:
Sorry, sitting on the head reading this and don’t have the ambition to read the whole thing. I know your impeller is junk. That’s obvious. But why? Could it be from lack of flow to it? I admit I am not familiar with your outdrive, however, I have seen outdrives that had the hose clamp on the drive water pickup hose come off. The engine would run cool all day long until you got up on a plane and the drive/hose came out of the water and it just sucked air. My 2 cents. Might not help you but might help someone else down the road. Good luck.
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We replaced the impeller and the flow appears good but we could only find 6 of the eight impeller fins. We are just making sure no pieces are stuck inside and my cause water flow issues while on out on the boat.
 
OK, if you're positive the inside of the housing is clear that's. That's a common "sticking point" so it was just good to be 100% sure.

If I was reading correctly, you checked/cleared everything else on the way to the t-stat housings so, as mention earlier, that's about all you can do. After that, they're somewhere in the engine and may or may not work their way out eventually.
 
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FYI everyone - ran the engine for about 15 mins with muffs. Boat temp was a consistently just below 170deg. Thanks for all your input.
 
Roger,

Testing on the muffs is all well and good, but remember that you're forcing water in under pressure that way.

The only way to be sure is to run it in the water to ensure that the pump is functioning correctly without the aid of the hose pressure.

Boating is fun ain't it?
 
Soulshine said:
Roger,

Testing on the muffs is all well and good, but remember that you're forcing water in under pressure that way.


The only way to be sure is to run it in the water to ensure that the pump is functioning correctly without the aid of the hose pressure.

Boating is fun ain't it?
Click to expand...

I'm a DYI person but this it testing my limits
 
Roger K Sterling said:
I'm a DYI person but this it testing my limits
Click to expand...

As it will.

Learing to DIY on your own vessel is not only a great cost saver, but you get things straightened out now, not when the mechanic can fit you in.

It also prepares you for emergencies and leads to a safer and more rewarding boating experience. The fact that you'll drink more is a sacrifice you'll learn to embrace.

You landed in the right place and there are many resources here.
 
Soulshine said:
As it will.

Learing to DIY on your own vessel is not only a great cost saver, but you get things straightened out now, not when the mechanic can fit you in.

It also prepares you for emergencies and leads to a safer and more rewarding boating experience. The fact that you'll drink more is a sacrifice you'll learn to embrace.

You landed in the right place and there are many resources here.
Click to expand...
Agreed. You don’t need to be an expert know it all marine mechanic, but you should be an expert with your own boat.
 
I just replaced my pump impeller after the engine over heated while idling out to bay. Since most of the fins on the impeller ripped off, I'm a bit concerned of bits getting stuck ... although idle test showed all is working well after change. I should have pulled my 290DA out of the water to change impeller but since it was just before memorial day my boat yard (BarnegatBay marina NJ) refused to help due to overload of work with other boats (that's another story), so I drove home on other engine. I would recommend impeller change before spring launch , just do it like every 3 years which I did not do ..... the impeller change can be done in the water but is a bit harder using plugs (i.e. pump below water level). I do agree DIY makes you more in tune with your boat and if you can't then get a pro. Yes, boating is fun and there is always something going on with the boat .....
 
SeaRay_Sam said:
I just replaced my pump impeller after the engine over heated while idling out to bay. Since most of the fins on the impeller ripped off, I'm a bit concerned of bits getting stuck ... although idle test showed all is working well after change. I should have pulled my 290DA out of the water to change impeller but since it was just before memorial day my boat yard (BarnegatBay marina NJ) refused to help due to overload of work with other boats (that's another story), so I drove home on other engine. I would recommend impeller change before spring launch , just do it like every 3 years which I did not do ..... the impeller change can be done in the water but is a bit harder using plugs (i.e. pump below water level). I do agree DIY makes you more in tune with your boat and if you can't then get a pro. Yes, boating is fun and there is always something going on with the boat .....
Click to expand...
You should definitely make a serious effort to find all of those impeller pieces. Start with the output of the pump and check everything down stream from there.
 
I replaced the thermostat since I think it was cooked after engine temp. went high due to impeller failure (most fins ripped off). Did not see impeller fins anywhere in thermostat housing after checking. However, I think I may have a faulty NEW thermostat (160 degree) because temp stays lower than normal on idle (130 degrees) until I run the boat. When running it goes to 170 then pops down to ~160 for a few minutes , then eventually goes to 174 ... which is in the limits of the 4.3L engine but of course it should be at 160 per thermostat specs. A friend of mine suggested it could be a bad thermostat and to try a new one ... which I shall do. I have to check water pressure in "smartcraft system view" to make sure there isn't a blockage BUT since its 130 degrees on idle before running on plane .... I would assume no blockage and a bad thermostat. Has anyone else has seen this issue ? I will replace thermostat and report back .... always interesting.
 
If you have an oil cooler and / or power steering oil cooler in the raw water line, the old impeller bits and pieces are probably hiding in the 1st cooler in the line, gumming up the works. Bigger pieces would never get to the engine.

Pull off the hose on the inlet of the 1st cooler and start checking in there. will be a bear to get in there and clean out, but needs to be done, since your old raw water pump failed miserably.
 
Bill Curtis said:
If you have an oil cooler and / or power steering oil cooler in the raw water line, the old impeller bits and pieces are probably hiding in the 1st cooler in the line, gumming up the works. Bigger pieces would never get to the engine.

Pull off the hose on the inlet of the 1st cooler and start checking in there. will be a bear to get in there and clean out, but needs to be done, since your old raw water pump failed miserably.
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Agree with this.

One thing I've found effective to finding bits down in the system is to use a wet/dry shop vac. Adapt the vac hose down to a smaller flexible hose, like the cheap hoses used on bilge pumps. Use one just slightly smaller than the water hose and fish it down the hose until it gets to the end (the heat exchanger or oil cooler). With the shopvac on, bounce the hose around a few times then look inside the vacuum to see what you've got so far. Rinse, repeat a few times and you might get lucky and get all or most of them out pretty easily. I had a friend do this to his generator. It avoided him having the disassemble the sound shield to get down to the heat exchanger and try and get the hose off down there. He did all the work right from where the hose left the raw water pump, which was easy to get to.
 
km1125 said:
Agree with this.

One thing I've found effective to finding bits down in the system is to use a wet/dry shop vac. Adapt the vac hose down to a smaller flexible hose, like the cheap hoses used on bilge pumps. Use one just slightly smaller than the water hose and fish it down the hose until it gets to the end (the heat exchanger or oil cooler). With the shopvac on, bounce the hose around a few times then look inside the vacuum to see what you've got so far. Rinse, repeat a few times and you might get lucky and get all or most of them out pretty easily. I had a friend do this to his generator. It avoided him having the disassemble the sound shield to get down to the heat exchanger and try and get the hose off down there. He did all the work right from where the hose left the raw water pump, which was easy to get to.
Click to expand...
I've used one on my generator. The vac was empty, I could hear the pieces come up the hose and into the vac.
 
SeaRay_Sam said:
I replaced the thermostat since I think it was cooked after engine temp. went high due to impeller failure (most fins ripped off). Did not see impeller fins anywhere in thermostat housing after checking. However, I think I may have a faulty NEW thermostat (160 degree) because temp stays lower than normal on idle (130 degrees) until I run the boat. When running it goes to 170 then pops down to ~160 for a few minutes , then eventually goes to 174 ... which is in the limits of the 4.3L engine but of course it should be at 160 per thermostat specs. A friend of mine suggested it could be a bad thermostat and to try a new one ... which I shall do. I have to check water pressure in "smartcraft system view" to make sure there isn't a blockage BUT since its 130 degrees on idle before running on plane .... I would assume no blockage and a bad thermostat. Has anyone else has seen this issue ? I will replace thermostat and report back .... always interesting.
Click to expand...


Update: Replaced thermostat and noticed part of therm casket was blown out on original, that is water pressure pushed its way around the thermostat which explains lower water temps when idling. When engine warms up and is running , its about 170-174 degrees which is above 160 for thermostat but is drivable. Noticed that my one riser/exhaust stays hotter when I flush the system (much warmer to touch compared to others) , which it NEVER did before ... thus my assumption is impeller bits are in my riser/exhaust, restricting flow throw it (partial blockage) and causing higher pressure back to thermostat. So, I removed hoses to riser and attempted to get a small camera in there and see .... but no luck since bend is to tight for flex camera. Sprayed a garden hose through it hoping to blow out bits but no luck ..... and yes, I know it was a bad idea .... for now I have to remove spark plugs to be sure water did not flow back into engine and cause hydro lock (yep, silly move). Hoses to and from risers are clear .... could this have nothing to do with impeller bits ? Maybe, but it all happened right after impeller failure . Stay tuned ..... I'll update as I move on .
 
Have seen the gaskets between the manifold and riser go bad, and the passages plug up with rust at the gasket.
 
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