Found the nasty surprise from my big block. I have a Cobalt 23 with the original Mercruiser 7.4 LX EFI + Bravo III 1997. I bought it last January with 205 hours on it, raw water cooling, always stored on a lift since new but Now the last two months on a dock in salt water next to my condo. Surface rust on the engine a bit but runned like new with no leaks or oil consumption. I put almost 100 hours on it with everything running tip top all the time. Oil level always ok. A week and a half ago while driving I noticed the bildge kicking in and opened the engine hatch. Lots of steam and water spraying from the circulating pump heavily. Drove it straight to the closest dock which luckily was right next to me, maybe two minutes. The engine didn't over heat at least according to the gauge. Top fitting on the pump was rusted out totally. Changed the pump the next day and fired the boat up. Ran fine and I let it reach the normal 175 temp. Now this saturday tried to take the boat out but it was running kind of shaking + some noise. Checked the oil and found it full of milkshake up to the half way of the stick so big time overfull with water mixed with oil. Obviously didn't start it again but pulled the riser and the exhaust manifold from the port side just to see that they were almost like new. The other surprice was that sometimes earlier the (I guess old ones) manifolds had been leaking as the underside of the heads were heavily rusted with the bolt heads almost gone so pulling the heads would be a pain... The exhaust valves were dry at least on the port side.
The question is, is the engine toast with the water being with the oil for maybe two weeks? It was still running with normal temp and oil pressure when I noticed this. Naturally I need to find out where the water got in but is it even worth messing with this 10 year old engine or just start looking for a replacement long block? I'm in Florida and Rapidomarine has been out of stock with BB's for 6 months. Any good suggestions/ideas? Thanks in advance, it's my first post, I wish it would've been something positive.
The question is, is the engine toast with the water being with the oil for maybe two weeks? It was still running with normal temp and oil pressure when I noticed this. Naturally I need to find out where the water got in but is it even worth messing with this 10 year old engine or just start looking for a replacement long block? I'm in Florida and Rapidomarine has been out of stock with BB's for 6 months. Any good suggestions/ideas? Thanks in advance, it's my first post, I wish it would've been something positive.
