Overheat - Impeller replaced

[Krueges3]

Hey guys, just trying to think if there is anything else I should look at once my new thermostat comes in.

VP 5.7OSI-300-J

I recently replaced the impeller which was damaged and had rocks/muck in it. I recently hit a shallow point and sucked up a bunch of silt and muddy water in a lake channel. Began to overheat.

After the impeller - ran the engine for about 10-15 minutes before it started to go over 175 and then I shut it down.
After running, the raw water hose to the impeller and then the water line from impeller to thermostat were both warm.
The large hose running from the thermostat to the water circulation pump were the hottest.

I drained both exhaust mafs, and all hoses before starting it up.
I didn't run a temp gage which I now have, but the right exhaust riser was slightly warmer than the left side. I will verify when i replace the thermostat.

Is there anything else i should be pulling apart to check?

Thanks!

 

[alldodge]

Is the motor raw water cooled or closed cooled?

Remove all the hoses and start back flushing everything.

 

[Krueges3]

Raw water, by back flush do you mean by attaching to the hose attachment on the engine?

 

[alldodge]

Remove the hose coming from the drive to the pump and use a garden hose to flush the hose back toward the power steering cooler and back to the drive.

Remove hose going from pump to to thermostat housing, and flush back toward the pump

Remove the large hose going to circulating pump and flush the block and circulating pump, thermostat housing

Same with exhaust manifolds

Remove block plugs so they can be flushed

Just anywhich way you can to try a flush the crud out

 

[QBhoy]

Agree with above. I’d also ask if you are running it in the water or on the trailer and hose ? May well have an effect on things.

 

[Krueges3]

Alldodge, thanks so much for the detailed reply.
Qbhoy - currently in the water. If there's no better way to do it, I will probably need to bite the bullet and just pull it out.

 

[Krueges3]

Just to follow-up on this. I followed the procedures and flushed everything, it was pretty messy. In total, I ended up changing the impeller, thermostat (needed), and unfortunately the fuel pump whine had started so I got that taken care of too.
Used the boat 3x after, worked great, and then now running at idle through a channel I saw the temp get close to 190-200 and I turned it off. Checked the hoses, all clean, the only thing that was out of the norm was the hose going from the thermostat to the engine water circulation pump. There was water in it, but it was very hot. Any other ideas what might have caused this?

 

[alldodge]

My understanding is the motor did fine until the impeller needed to be replaced and it was full of muck. The motor and hoses have been flushed but it starting to over heat again.

If this is true, then there is still something clogging the block, or water is not circulating

 

[wmubronco]

Just to follow-up on this. I followed the procedures and flushed everything, it was pretty messy. In total, I ended up changing the impeller, thermostat (needed), and unfortunately the fuel pump whine had started so I got that taken care of too.
Used the boat 3x after, worked great, and then now running at idle through a channel I saw the temp get close to 190-200 and I turned it off. Checked the hoses, all clean, the only thing that was out of the norm was the hose going from the thermostat to the engine water circulation pump. There was water in it, but it was very hot. Any other ideas what might have caused this?

I feel I'm right there with you, but did not get to flushing out my manifolds just yet. Big house from thermostat is hot as well, and I feel my engine just is not pushing out the hot water, which caused the hot temp. alarm;
https://forums.iboats.com/forum/eng...perhaps-tied-to-slight-thermostat-overheating

I wish you luck as I will watch this thread too!

Patrick

 

[Scott Danforth]

you have to back-flush everything........ starting at the manifolds and work your way to the raw water pickup hose that goes from the trans shield to the drive

some times you have to pull the block drains to get sediment out of them

some times you have to pull the manifold drains to get the sediment out of them

some times you have to pull the PS cooler (and oil cooler if you have one) to get the sediment out of them

 

[Krueges3]

Everything was flushed in sequence last time but I plan to do so again. The odd thing is that after getting through the channel I anchored, pulled hoses etc and then let it cool down before turning around and heading back to the dock. I noticed the temp never went higher than it should and then I just kept it running while docked to see if it would happen again. Of course not.

 

[wmubronco]

Everything was flushed in sequence last time but I plan to do so again. The odd thing is that after getting through the channel I anchored, pulled hoses etc and then let it cool down before turning around and heading back to the dock. I noticed the temp never went higher than it should and then I just kept it running while docked to see if it would happen again. Of course not.

Any luck?