Checked impeller and its not damaged. Diesel engine overheating and raw water is not exiting back of boat. No antifreeze or coolant. What now?
Inboard raw water not pumping out of back overheating
- Thread starter Jkirkendall91
- Start date
Make sure that intake strainer is not blocked as a start point and you actually getting good flow on inlet of raw water pump.
You mean not only are you not pumping raw (sea) water, but you also have no coolant in the engine?
Are you experienced with this boat, or new to it? New to inboards?
Is it fresh water or raw water cooled?
Are you experienced with this boat, or new to it? New to inboards?
Is it fresh water or raw water cooled?
Then it's simple: you have a clog, or the impeller isn't turning. The impeller could have failed in the rubber part's attachment to its hub. Not likely, though. Can you remove the pump output hose and crank the engine to see if it's pumping? Then work your way though the system from there, through the block and manifold, to the injection elbow.
@Jkirkendall91
First... Welcome to the forum. You are already getting a handle on how to use it. Ask questions, look at the responses, try one or two of them then come back with results. Pictures help to clarify your observations of a problem. Sometime we see more in the image then you are describing.
You are starting at the easiest end to address the problem. Water must come out the exhaust to keep your engine cool. So starting at the beginning (where water goes in) is a very good place.
The strainer. Is it above the water level or below. If below you can open it up and water should come flowing out.
If above the water line then the engine pump will need to draw water in to the strainer.
Follow the lines and with the thru hull cracked a bit open see if water is available all the way to the engine water pump. Here we are checking to assure the lines are clear.
Next, with the thru hull closed, open the raw water pump. Should be 4 screws in the face cover. You will know the pump because you have traced the hoses from the thru hull pass the strainer to the pump. Open the face cover and inspect the raw water impeller. It should look something like this.
or this 
If you see any of the vanes cracked or missing you have found your problem. These should be checked and often changed yearly. You will need to identify your pump and get the proper "Impeller" to fit. You will want to have a spare on the boat.
SO get a new one for your engine and then do the inspection. You may find a new looking one in your boat. and the new one you just bought is now the spare. You may find it looks something like this...
no there is your problem.
Here is a service link that my help. https://www.westmarine.com/WestAdvisor/Impeller-Replacement-101
First... Welcome to the forum. You are already getting a handle on how to use it. Ask questions, look at the responses, try one or two of them then come back with results. Pictures help to clarify your observations of a problem. Sometime we see more in the image then you are describing.
You are starting at the easiest end to address the problem. Water must come out the exhaust to keep your engine cool. So starting at the beginning (where water goes in) is a very good place.
The strainer. Is it above the water level or below. If below you can open it up and water should come flowing out.
If above the water line then the engine pump will need to draw water in to the strainer.
Follow the lines and with the thru hull cracked a bit open see if water is available all the way to the engine water pump. Here we are checking to assure the lines are clear.
Next, with the thru hull closed, open the raw water pump. Should be 4 screws in the face cover. You will know the pump because you have traced the hoses from the thru hull pass the strainer to the pump. Open the face cover and inspect the raw water impeller. It should look something like this.
or this If you see any of the vanes cracked or missing you have found your problem. These should be checked and often changed yearly. You will need to identify your pump and get the proper "Impeller" to fit. You will want to have a spare on the boat.
SO get a new one for your engine and then do the inspection. You may find a new looking one in your boat. and the new one you just bought is now the spare. You may find it looks something like this...
no there is your problem.Here is a service link that my help. https://www.westmarine.com/WestAdvisor/Impeller-Replacement-101
Suggest you also supply the make and model of the engine and also the boat.
For this particular problem it will help you if you know the whole path of the raw water circuit. In through the through hull, then the seacock, then the raw water pump, then the heat exchanger, then the exhaust manifold, then into the mixing elbow, then out the exhaust. On my Yanmar 3QM I can easily blow through any of these components (except the raw water pump) and this is a good way to diagnose where a blockage may be. I have had a problem that was caused by crud accumulated in the exit of the water passages in the exhaust manifold. The best is to work you way systematically through the whole circuit. It also pays to clean it all up, not just fix the obvious.
For this particular problem it will help you if you know the whole path of the raw water circuit. In through the through hull, then the seacock, then the raw water pump, then the heat exchanger, then the exhaust manifold, then into the mixing elbow, then out the exhaust. On my Yanmar 3QM I can easily blow through any of these components (except the raw water pump) and this is a good way to diagnose where a blockage may be. I have had a problem that was caused by crud accumulated in the exit of the water passages in the exhaust manifold. The best is to work you way systematically through the whole circuit. It also pays to clean it all up, not just fix the obvious.
Had this problem myself awhile back. After completely rebuilding the raw water pump (it needed it anyway) I discovered that the mixing elbow was clogged with black soot. This happens to all of them eventually. I used a screwdriver to scrape out the black soot and all was good again. The way to check this is to disconnect the hose that runs from the pump to the mixing elbow where it attaches to the elbow. If water comes out of said hose when engine is running then you have a clogged mixing elbow.
Thanks guys! All really great advise gonna attempt to see if their is a clog in the elbow. Found out my friend tried to do oil change and put water into this...don't even ask how..."I will destroy my own engine thank you very much." Is what itold him. Keep you posted
Attachments
Here is one tool.
https://www.amazon.com/gp/aw/d/B002YKIZBA?psc=1&ref=yo_pop_mb_pd_title
https://www.amazon.com/gp/aw/d/B002YKIZBA?psc=1&ref=yo_pop_mb_pd_title
Sweet gonna get that in the morning. In the me time thinking about removing the heat exchanger and giving it a wash. That's this right?
Attachments
Yes. Looks like it has had some copper corrosion (turning green) as a result to moisture. Good idea to clean just like you do with a car radiator. If you find pinhole leaks than worse case you may need replacement.
@LeslieTroyer just changers his out on his Catalina 36. He might share insight. Send him a PM.
@LeslieTroyer just changers his out on his Catalina 36. He might share insight. Send him a PM.
The black thing looks like your exhaust hose. The part prior to that wrapped in the cloth is your mixing elbow. I would start at the beginning and open the strainer while seacock is open and see if you get water rushing out.... assuming it’s belowwaterline. If it’s above the water line you may have to prime it. If boat has been sitting the fitting in the hull could be fouled with growth and sea creatures cutting off water as well. And also know..... you don’t want to flood your engine so Be careful. When you start engine can you see exhaust existing tailpipe?
Good luck!
Greg
Good luck!
Greg