Forgot to drain engine block last fall

DickR · 06-26-2011, 09:29 AM

My boat has a 1997 3.0 liter Mercruiser Alpha One, 130 HP engine. Last fall I forgot to drain the block and add RV antifreeze protection down the hoses to cover any residual water that didn't drain out, as I normally do. I wasn't sure if I had or had not drained the block until yesterday. Nope, I hadn't, as a fair amount of water drained out when I removed the plug. I can't see any damage on the outside of the block, and I haven't tried to start it yet. The dip stick shows just oil at about the right level (higher might have indicated water below the oil in the pan).

The questions are first how likely is freeze damage to have occurred and then how to tell if damage has been done? I suppose I could just launch the boat, start the engine, and observe it, check the oil for water/oil emulsion forming, oil slick on the water, etc. I would think there is a better way than this. Any opinions?

06-26-2011, 09:29 AM	#1
DickR Senior Member Join Date: Apr 2008 Location: Moultonborough Posts: 765 Thanks: 4 Thanked 260 Times in 172 Posts	Forgot to drain engine block last fall My boat has a 1997 3.0 liter Mercruiser Alpha One, 130 HP engine. Last fall I forgot to drain the block and add RV antifreeze protection down the hoses to cover any residual water that didn't drain out, as I normally do. I wasn't sure if I had or had not drained the block until yesterday. Nope, I hadn't, as a fair amount of water drained out when I removed the plug. I can't see any damage on the outside of the block, and I haven't tried to start it yet. The dip stick shows just oil at about the right level (higher might have indicated water below the oil in the pan). The questions are first how likely is freeze damage to have occurred and then how to tell if damage has been done? I suppose I could just launch the boat, start the engine, and observe it, check the oil for water/oil emulsion forming, oil slick on the water, etc. I would think there is a better way than this. Any opinions?