Mercruiser 4.3 oil sensor loose leaking oil

I have a 98 stingray 190lx with a mercruiser 4.3L 2bbl carb.

This spring I've had a few things wrong. This all started when I was doing some night fishing and my alarm went off on my depth finder for shallow water. I slowed down by putting this into neautral and shutting off the motor very quickly. I also trimmed it up as fast as I could. I was scared I was going to tear off the lower unit in shallow water. Well When I realized I was still in deep water I the boat wouldn't start. Something was wrong on the starter. I put the boat into storage and did winterize it with antifreeze. However being that it wouldnt start I couldn't fog it.

Update to this. Pull the boat out and I replaced the starter. Boat won't start. I needed to do an oil change anyways so I went to change the oil and I have water in the oil while Im pumping it out. Keep this in mind. The water was milky with the oil. It was water coming out of the oil pan. I had allready has the oil filter off so I lost alot of oil out of that to. But that oil was not Milky. Ok so i finished the oil change. And filled the lower unit up with lube.

Now I try to start it. It won't. I check fuel. good. I check all spark good. So I pull out the plugs and my plugs are rusty. All 6 plugs looked this way. From water being on top of the pistons I am sure. I read the mercruiser diagnosis what to do when water is found on the motor was very helpful. I sprayed some oil down into the spark plug holes and gapped and put in new plugs. Engine turned over for about 10 seconds that started right up and smoked alot which is to be expected. So now the engine starts and runs fine.

Problem 1: How did the water get in there is the first place? I'm thinking when I stopped fast the motor dieseled and sucked water back up into the engine. Well I didn't realize that and since my starter was out I couldnt start it to find out that happened. So it sat all winter this way apparently. Engine does start up right away and idle well I have not ran it for any long period. just a few seconds. So now with this happening whats the chances my engine is going to be ok or will it be to corroded? Possibly cracked block or heads to.

Problem 2: I thought I had a oil leak on my oil filter. It appears to be from the oil sensor by the filter. It is not tight its kind of loose on there and I can't find a way to tighten it. Any ideas here?

Thanks for any ideas or help.

Re: Mercruiser 4.3 oil sensor loose leaking oil

Welcome to iBoats....

You have a cracked engine block.... By just tipping antifreeze in you still had a lot of pure water in there... It froze and cracked the block.... All other problems are now irrelevant.... First replace the block or the engine... Check your manifolds too...

Re: Mercruiser 4.3 oil sensor loose leaking oil

Thanks. Yea this is a pretty nice site.

thanks for the good news.

Re: Mercruiser 4.3 oil sensor loose leaking oil

Update to this:

Pulled off the oil sensor and tightened it up. It now does not leak.

Ran the engine on the muffs three times today. Engine oil level did not change. Oil did not appear to be milky at all. Going to get it out on the water hopefully tomorrow and try it out for a few hours. If I see no raise in oil level and no milky oil I am going to possibly assume its ok.

I think I am going to still try and pressure test the block. Does any one have a write up how to pressure test this engine?