My 4.3 v6 is blowing steam

[Clownfish]

I have a 1996 mercruiser vortech v6 4.3L and its blowing steam after about 1 or 2 mins after i start it up it coming out of the center of the propeller and a little bit around where the water pees at two spots behind the stern. i dont remember it ever doing this before and also it does not want to idle it will run fine when u rev it up past 1500 or so rpms im thinking its getting water into the cylinders causing the steam and idleing problem. also when the boat sits for a week week and a half or so it gets water in the cylinders both sides and some times only one side and some times its not in the same cylinders. i had been taking it to the lake still even when it was haveing the water in the clinders cause i would just remove the spark plugs to drain it out before going to the lake if the water was in there. as long as i would crank it a few times a week it wouldnt get the water in there to prevent it from starting so i never tryed to fix it or take it some where to have the problem fixed and i didnt have the extra cash so i just ran it like that and it was fine. but now im getting this steam and it not wanting to idle so i got to do something about it this season i have not gone this season because of it.

Im thinking the problem might be a crack in the intake manifold.
i would like to know everyones ideas before i go pulling the intake off to check it

 

[winterfunguy]

Re: My 4.3 v6 is blowing steam

If you are getting water into alternating cylinders the problem is most likely the intake you will have to have it pressure tested at a machine shop to verify it though.

 

[dubs283]

Re: My 4.3 v6 is blowing steam

bad head gasket(s),
cracked head(s),
bad exhaust manifold(s)/gasket(s),
bad water shutter(s),
water entering through the carb/air intake - i.e. rain water due to faulty boat/engine cover

these are a few possible causes of your water in cylinders problem

a compression test will tell you a lot about the condition of the engine