Re: Amel's suggestion to run the Volvo D3-110 (A54) daily while on passage
Mike,toggle quoted messageShow quoted text
A few things that you might check on your exhaust system that could be the cause:
1. Check to be sure that the exhaust hose is looped as high as possible between the muffler and the discharge. Perhaps a previous owner used less hose and lowered the loop from the original design? In order for seawater to enter from the exhaust port it has to climb over this loop so the higher is better.
2. Insure that your muffler is working properly. Run the engine, shut down and then remove the exhaust hose to the muffler. I like to see the muffler less than 1/3 full due to the drain back from the exhaust hose. In order for the engine to flood from the exhaust port the muffler first has to fill with water. If the muffler has more water than this, you could have a problem inside the muffler that does not allow the engine to properly clear the muffler usually due to corrosion.
3. Engines can also flood from the seawater intake side of things. The line should be looped as high above the WL as practical and there should be a vent at the top of the loop that must function or seawater can be siphoned over the loop and into the engine. Insure that the vent is working properly.
4. Ensure that the seawater injection elbow normally located at the connection between the exhaust manifold and the exhaust hose is not corroded through.
My boat is a Maramu so our systems are probably somewhat different. I have removed the exhaust hose a few times after a rough passage and before starting the engine to see how much water had accumulated in the muffler and so far the level has always been nominal, or about the same as after shutting down the engine while dockside. I have therefore not been too concerned about running my engine on passage and have not had any water in the engine to date.
There are a number of low pressure check valves that you can install in the exhaust system to help prevent seawater from being driven in the exhaust port that you could look into but I suspect your problem is due to a faulty component or some change that has been made in the design of the exhaust system. Best of luck to you, seawater can sure do a lot of damage to your engine so I hope that you can find the cause and rectify it.