288sunny

Hopefully someone has some ideas, i have a 496H0 with dana marine exhaust that im having a issue with, or atleast i think.. For startes i had some water in the oil, so i pressure tested the cooling system and i did not have any sudden drops, there was some leakage over some time, but nothing huge. Could this be a problem? Also i have checked my plugs a few times and most of them are a very light tan with some white streaks, which tells me theres possible water or coolant getting to them and the piston as well as valves.. Not sure where to look? I have pressure tested the oil cooler and it tested good.. Oil on the the dip stick appears new and normal, didnt look milky but i havnt drained the oil again yet.. Ive already ran 18 qrts through it, this oil looks alot better than the first.

Anyways the only things i can come up with are, plugs dont look normal, very slight cooling system pressure loss, and when im at idle i notice steam out the exhaust.. cant tell while im running cause i see mostly water at that point.. Any help would be awesome, i really hope i dont loose a motor, but who knows only time will tell..

Raylar

Shaun:

After a conversation with Bob at Dana Marine the other day, I still kind of feel that your problem with water getting back in your motor is from the captains call exhaust diverters and the way that system fits and may be installed behind the Dana manifolds. I don't know of any other boater with a stock engine and Dana header manifolds who is having this problem.
If I had a high performance engined boat today I would not use captains call or silent choice period! My opionon and one shared by Mercury Racing.
I would reccommend checking the Dana system for any possible leaks and if they don't leak, which I doubt they do on both sides and if not then I would remove the captains call, run the exhaust staight out the transom and install a good set of muffler tips.

Best Regards,
Ray @ Raylar