Hi, looking for advice… I replaced my impeller on my Yanmar 56hp diesel (the old one had a few cracked blades but everything was intact) and when turned on the engine the water flowed through normally out the stern but I now have load vibrations at the stern of the boat. Nothing is loose, the engine is running fine with no apparent vibrations with the engine mounts. Now the engine is overheating. I replaced the impeller again and the vibrations are less but still there. I ran the engine again for a half hour and again it overheats. I bled the antifreeze line and there seemed to be a little air in it but then the antifreeze flowed. I also checked the lines on either side of the thermostat and antifreeze was present. One other observation, I opened the hot water facet and the water was only luke warm, I would have thought the water heater would have warmed up nicely as the antifreeze line runs through the water heater. Any advice is most welcomed. Cheers
thanks for the thread, some good points to consider. im pretty sure the impeller I replaced was intact but you never know... i'm getting a lot of water flowing through the exhaust so its not completely blocked.
I haven't read the previous thread so this may be a repeat. If you have a thermostat, it could be clogged. On my boat water is still passed to the exhaust even when the engine is cold and the thermostat is closed. You could have the same situation.