Leak in 3000 SCR

[jayesq]

Last year I noticed a large amount of water under the starboard engine, gallons of water after going out with a loaded boat. In the off season I had all the bellows replaced, the mechanic who I have used for some time found some minimum evidence of leaking in one of the bellows, but nothing substantial. This year have been out several times without any noticeable water penetration, then about 3 weeks ago I went out with a full boat saw the bilge light come on checked the bilge and found a large amount of water under the engine. It slowly drains down into the main bilge. Came back to the marina and took the engine up to operating temp and 3500 rpms and no evidence of water. Went out a couple days later with the mechanic ran it wot for about 45 minutes and not a drop of water. Packed up the family for a trip to long island got about 10 miles out and bilge light is on. Checked the bilge and a large amount of water under the starboard engine again. If I keep the boat under about 2700 rpms with a fully loaded boat no water is coming in. Once I go above that I am taking on substantial water. I have hosed down all the exposed thru-hulls on that side for 15 minutes and don't get a drop of water. No water penetrates sitting at the dock or when I put it in reverse. I replaced manifolds and risers last year. I am not losing any water from the fresh water holding tank. If anyone has any thoughts or ideas I would appreciate hearing them. I am scheduled to meet up with the mechanic again later in the week.

[mmwjr]

Did the mechanic inspect the swivel shaft for leaks? It's the steering shaft on the transom assembly and are know to leak over time.

[jayesq]

I will have to check with him. Thank you for the input.

[Kevlar7r]

Mike, wouldn't the swivel shaft be out of the water when he is on plane? If that leaks it should do the opposite of what he is experiencing... would leak at the marina, not leak underway.

I am thinking maybe a pinhole leak in a water hose. When under load, the water pressure is going to be higher in the cooling system due to the pump spinning faster. Plus, you get some added pressure from the intake moving through the water at 30mph. It might be a leak small enough that it isn't leaking at idle.

Although, you did run with the mechanic and it didn't happen.

Risky, but I might take the engine hatch off completely and go run, with someone able to watch the whole engine compartment (from above of course)

[mmwjr]

Originally Posted by Kevlar7r

Mike, wouldn't the swivel shaft be out of the water when he is on plane? If that leaks it should do the opposite of what he is experiencing... would leak at the marina, not leak underway.

I am thinking maybe a pinhole leak in a water hose. When under load, the water pressure is going to be higher in the cooling system due to the pump spinning faster. Plus, you get some added pressure from the intake moving through the water at 30mph. It might be a leak small enough that it isn't leaking at idle.

Although, you did run with the mechanic and it didn't happen.

Risky, but I might take the engine hatch off completely and go run, with someone able to watch the whole engine compartment (from above of course)

For the most part I agree with you unless he is trimmed bow high. Also since the mechanic had done some work in the area I thought it would be wise if you checked this out as well.

[jayesq]

Didn't pull the boat yet but pretty much have excluded every other possibility. Mechanic believes probably is the steering seal that was discussed. The more it was used the more it appeared that water penetration occurred while getting on plane with a heavy load which is why when I went out with the mechanic I could not replicate it because I jumped right on plane rather than keep the stern buried. After I pull her I will provide an update.