My 753 popped the plug behind the gear case. Not fun to fix.Depending on you storage conditions it could have accumulated water from condensation in the block. I would drain the oil and see how much water comes out. If there is not a LOT of water I would put in fresh oil and new filter and run again and see what happens. If it shows water again you need to investigate. I would start by removing the valve cover and see if that engine has core plugs in the valve area. I have seen them rust and leak water into the oil.
Foam is hopefully just air, if it's milky when you allow it to sit and settle, there is water in there that you need to get out.My 753 popped the plug behind the gear case. Not fun to fix.
Thanks everyone for the suggestions. There was some water in the oil. I drained the oil overnight. Then refilled and drained again. Changed the filter. Removed the valve cover and cleaned/dried everything I could see. The other problem is one of the freeze plugs popped on the back of the cylinder head. I pulled the engine so I could reach it. Sandblasted the plug clean and tapped it back into the head with a socket about the same size. A few of the seal plugs under the valve cover were also loose - maybe this is where the water came from? I tapped them back into place. Next I pulled the head and it did not show any obvious flaws. Waiting on a new head gasket before I reinstall the head. Also waiting for a pressure testing tool to arrive so I can test the cooling system for leaks. What am I forgetting? Are there any other details for reinstalling the freeze plug? Should I replace the plug with a new one? Should I take anymore steps to remove water? Thanks again.Foam is hopefully just air, if it's milky when you allow it to sit and settle, there is water in there that you need to get out.
"Should I replace the plug with a new one? " Yessir, you never install a used freeze plug, it's not going to fit tightly like a new one. Whether it's the concave or convex type you want to remove all rust and crud that's built up around the plug hole. When installing, coat the plug edge or edge of the hole with Permatex Aviation sealer (the brown stuff). It's sold in most all parts houses. When you drained the oil after sitting overnight did any pure water come out first? After an engine sits and has not been started, the water is heavier than oil and it will completely separate from oil and be at the bottom of the pan.Thanks everyone for the suggestions. There was some water in the oil. I drained the oil overnight. Then refilled and drained again. Changed the filter. Removed the valve cover and cleaned/dried everything I could see. The other problem is one of the freeze plugs popped on the back of the cylinder head. I pulled the engine so I could reach it. Sandblasted the plug clean and tapped it back into the head with a socket about the same size. A few of the seal plugs under the valve cover were also loose - maybe this is where the water came from? I tapped them back into place. Next I pulled the head and it did not show any obvious flaws. Waiting on a new head gasket before I reinstall the head. Also waiting for a pressure testing tool to arrive so I can test the cooling system for leaks. What am I forgetting? Are there any other details for reinstalling the freeze plug? Should I replace the plug with a new one? Should I take anymore steps to remove water? Thanks again.
Thanks JDWY. I will replace the plug and use Permatex. I did not let the engine sit before draining. While it was foamy, I opened the drain and left it overnight."Should I replace the plug with a new one? " Yessir, you never install a used freeze plug, it's not going to fit tightly like a new one. Whether it's the concave or convex type you want to remove all rust and crud that's built up around the plug hole. When installing, coat the plug edge or edge of the hole with Permatex Aviation sealer (the brown stuff). It's sold in most all parts houses. When you drained the oil after sitting overnight did any pure water come out first? After an engine sits and has not been started, the water is heavier than oil and it will completely separate from oil and be at the bottom of the pan.
You are welcome. Any chance it was severely overheated just before it sat for a year? If so, that could account for the sudden water in oil problem--blown head gskt, cracked cylinder head, freeze plug problems, etc. Also if that's the case it would be wise to have the head magnafluxed for cracks. Most always a head will crack at the web between the exhaust and intake valves and can be hard to detect unless the carbon is removed and closely checked.Thanks JDWY. I will replace the plug and use Permatex. I did not let the engine sit before draining. While it was foamy, I opened the drain and left it overnight.
