Koehler 7.3ECD overheating


F

FormulaLP

New member
My genset is on a 2008 34 PC. The error message says to open the seacock. The valve is open and the strainer is clean. Any ideas? I wonder if I can install a larger water pump. Any suggestions would be appreciated.
 
Check the water flow coming out the Starboard side. Does it look adequate? Also check the heat exchanger, it may be fouled. Easy enough to pull apart, 3 bolts on each end to remove the tube bundle.
 
When you replaced the impeller, did the old impeller have all its vanes attached.

If not, did you retrieve all the impeller vanes sitting in the impeller housing or tube running from the impeller to the heat exchanger or in the exchanger itself or all the above?
 
When I replaced the impeller it really could’ve been reused. I replaced it anyway since it was apart. As far as checking the water flow, it seemed like the amount of water it was designed for. I had a SeaRay previously and the intake was larger. But, with that said this is all stock, so I’m sure it is per design. I did not check the heat exchanger. I will next time I’m at the boat. Thanks for the input
 
I would suggest opening the sea cock with the cap off of the strainer off to see how much water flow you have through the screen. I had small fish stuck in the suction line that allowed enough water through to keep the impeller intact but not enough to adequately cool. This blockage was prior to the screen. The fish was too big to get to the screen.
 
This is basic thinking but maybe worth a try. If you have your 30 for PC on a lift or can get it out of the water open the seacock and remove the strainer. With a stiff wire or a fish tape snake the hose from the strainer housing to the seacock. Next use a water hose to blow the hose and water intake clear. It helps if a second person can tell you if the water is exiting the intake without restriction. Remove move the hose at the water pump coming from the strainer housing. Sneak this hose out from top to bottom. With a couple of quick blasts of water in the hose watch the strainer housing again for debris. Put the cover back on the strainer housing leaving the strainer out. Again with the water hose under pressure flush the hose through the system until it exits the hull without restriction. Replace the clean strainer and water pump hose. Even if this does not work it will eliminate any doubt of restricted water flow. Good luck
 
ScrUbjae said:
This is basic thinking but maybe worth a try. If you have your 30 for PC on a lift or can get it out of the water open the seacock and remove the strainer. With a stiff wire or a fish tape snake the hose from the strainer housing to the seacock. Next use a water hose to blow the hose and water intake clear. It helps if a second person can tell you if the water is exiting the intake without restriction. Remove move the hose at the water pump coming from the strainer housing. Sneak this hose out from top to bottom. With a couple of quick blasts of water in the hose watch the strainer housing again for debris. Put the cover back on the strainer housing leaving the strainer out. Again with the water hose under pressure flush the hose through the system until it exits the hull without restriction. Replace the clean strainer and water pump hose. Even if this does not work it will eliminate any doubt of restricted water flow. Good luck
Click to expand...

I will be at the boat in a few weeks and I will give this a try. I will post the results, thanks
 
There is no need to go through the time and expense of pulling the boat out. Just take off the strainer cap and open the seacock. You will be able to see how much water is flowing under normal conditions of the boat stopped and in the water. I would strongly suggest doing this first. On my 37PC the distance from the seacock to the strainer is about 8". Its not a long distance to figure out what is happening.
 
Jet nailed it. Check the short intake line from thru hull to the strainer. Were were on a ball in Gloucester for a night with a lot of sea grass floating around. Went to start the genny in the morning for breakfast. She started and ran for 10 seconds and shutdown. Cleaned out the stuffed strainer and tried again. Same.

Once I looked closer I saw the short intake line was packed with grass. Cleaned out and she ran fine. Good luck
 
Does it run, then shut down a few seconds later...throwing the cooling code? If so, was there plenty of water coming out of the side discharge? If all of this, it's probably the cooling water flow sensor that inserts into the heat exchanger. If it senses lack of cooling flow...or if it is defective....it shuts down the genset. Unplug one of the two plugs on the sensor and start the genset. If it runs, replace the sensor.
 
It?s the water flow sensor. It took a bit but that was the problem.

V1rowT8 said:
Does it run, then shut down a few seconds later...throwing the cooling code? If so, was there plenty of water coming out of the side discharge? If all of this, it's probably the cooling water flow sensor that inserts into the heat exchanger. If it senses lack of cooling flow...or if it is defective....it shuts down the genset. Unplug one of the two plugs on the sensor and start the genset. If it runs, replace the sensor.
Click to expand...


thanks everyone for the input. I replaced the sensor and it runs great. Happy boating
 
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