white steam discharge..

Discussion in 'Sport Cruisers' started by The Heysers, Feb 18, 2009.

  1. The Heysers

    The Heysers New Member

    16
    Jun 29, 2008
    Tallahasse, FL
    when running our twin 454 cruisaders, there is a lot of white steam coming out of the back.. not really smoke and doesn't smell like oil. Is this a problem with the exhaust manifolds? If so, what is a ball park cost to repace them.


    Bill and Kristen
     
  2. NorCal Boater

    NorCal Boater Well-Known Member SILVER Sponsor

    Jan 24, 2008
    Covington, LA
    Boatless
    No boat....no engines
    Some steam is normal. I had a lot from the starbord exhaust when I had a raw water impeller go bad on the SB engine. Make sure you have good water flow from the outside exhaust ports. Do you know when the raw water impellers were last changed?

    The water coming out of those ports is the raw water that goes through the heat exchanger. If there is a restriction, either the water pump or the manifolds, the water stays in the raw water system a bit longer than it should, gets hotter and will generate more steam.

    Someone else will most likely chime in but I would get this checked as soon as possible.
     
  3. The Heysers

    The Heysers New Member

    16
    Jun 29, 2008
    Tallahasse, FL
    we had a bottom job last spring and the bottom still looks good, so not too worried about build-up blocking the water going in. we changed impellers back in the fall... that's what makes me think the exhaust manifolds need to be changed.... any thoughts? Thanks so much for all of your input. norcal!
     
  4. skolbe

    skolbe Well-Known Member

    Oct 3, 2006
    St. Louis, MO
    320 Sundancer, Zodiac 290 Wave Inflatable Tohatsu 6HP
    350 Mag V-Drive - Kohler 5ecd
    Could be a clogged sea cock, strainer or hose. Which in turn starts causing your impeller to wear prematurely. But low water flow can cause more steam.
     
  5. comsnark

    comsnark New Member

    Apr 10, 2007
    NJ Shore
    SeaRay SunSport
    5.7LX
    Or a head gasket leak.

    I would get a thermal gun and check the temps while running. If the risers are hot. . then you have a cooling problem and the impeller / thermostats would be the first things to check.
     
  6. The Heysers

    The Heysers New Member

    16
    Jun 29, 2008
    Tallahasse, FL
    thanks for the addtional imput... in the fall, a mechanic did shoot the temp gun and he recommended taking out the thermostats altogether. He told us then that we would soon need a new manifold, but to run it and see if it cleared. He recently told us that they run about $1000 each plus labor (so $2000 plus labor). I was looking online and the exhaust manifolds seem to only be a couple of hundred dollars each. We don't know this guy very well.... are we getting jacked around??? Very hard to know who to trust and who not to in the boating world!!!

    Thanks.
     
  7. tdappleman

    tdappleman Active Member

    Dec 17, 2007
    Kill Devil Hills, NC
    1996 270 Sundancer
    New twin 4.3's - 235hp each with Alpha 1 Gen 2 Drives
  8. sbw1

    sbw1 Well-Known Member

    Oct 10, 2006
    West Michigan
    This is listed in my signature
    This is listed in my signature
    Can't comment on your need for manifolds but I can say that every staight inboard boat I've owned has blown steam out the exhaust. It is very noticable in cold (50 degree) water but we make steam in July and August as well. I've never given it a second thought. I can't remember if my I/O boats produced steam. If they did, it might have been less because of the exhaust coming out below the water level. If you switched to an inboard from an I/O you may be seeing the difference. I would however get those manifolds checked out. On your boat, it's an easy job.
     
  9. Mike

    Mike New Member

    62
    May 29, 2007
    Middle River, MD
    I have twin 454's and steam as well. My water flow is good and my risers and manifolds were replaced last year. It will steam all season long and only under load.

    I have also asked this question before. I am hoping it is normal, otherwise I would think it is the head gaskets. But I have good power, both engines steam the same, temps are within 5 degrees of each other and hard to believe all four sides would blow.

    I also heard that it could be the lift mufflers that produce a little more steam then normal.
     
  10. sbw1

    sbw1 Well-Known Member

    Oct 10, 2006
    West Michigan
    This is listed in my signature
    This is listed in my signature
    I've not heard that but all of my inboards have had those mufflers. Do you know why they do that?
     
  11. 240da

    240da New Member

    105
    Jan 7, 2009
    Atlanta, GA/Lake Martin, AL
    2006 240 Sundancer
    350 MAG Horizon w/Bravo III 20p SS props
    Never take out your thermostat unless you like an engine filled with carbon!
     
  12. The Heysers

    The Heysers New Member

    16
    Jun 29, 2008
    Tallahasse, FL
    Absolutely a little steam is normal, but my port engine looks like I am putting on a Blue Angels demonstration at show center!!!! I also have good power and temperatures are balls on (that is an industry term I learned from watching My Cousin Vinny)... just the port engine steams much more than starboard... I love this website!!!
    Any other ideas?
     
  13. NorCal Boater

    NorCal Boater Well-Known Member SILVER Sponsor

    Jan 24, 2008
    Covington, LA
    Boatless
    No boat....no engines
    If one side is blowing more steam than the other you have a restriction somewhere. If you look at the water flow at aidle I bet you will see less water coming out of the port side. You could start by checing the port raw water strainer and check the seacock. Also make sure there is nothing stuck in the intake.

    DO NOT remove the t-stats. You might look at putting in new ones. But remember, the raw water does not go through the engine if your engines are fresh water cooled.

    Which brings me to Mike's comment about head gaskets....

    Mike, unless your boat is raw water cooled, which is fairly unlikely, the water that comes out of your side exhaust port does not go through the engine. It comes into the boat via the raw water intake, through the seacock and strainer, the raw water pump and into the heat exchanger where it cools the engine coolant. From there it continues into the exhaust manifold and then mixes with the engine exhaust, goes through the muffler and out the side of the boat. If the raw water is restricted it stays too long in the system and gets hotter thereby making additional steam.

    A head gasket leaking could contribute to the excess steam but you would be seeing a loss of engine coolant and increased engine temps.
     
  14. comsnark

    comsnark New Member

    Apr 10, 2007
    NJ Shore
    SeaRay SunSport
    5.7LX
    Yeah, head gasket is a possibility but a water flow problem is far more likely. When I say check temps, the temps on the dash are only ONE indication. You need to check each side individually.

    When I was having problems, I bought an IR gun from Sears for $80. Very instructive. On my boat, the manifolds are cooled with water from the engine (raw water design). Not sure how your system is routed. . . .but I wouldn't go further without troubleshooting the water system.

    When I was having problems, it took my mechanic about an hour to pull and inpect one riser assembly. It took him 10 minutes to replace a $25 thermostat (he refused to spend a full 1/2hr of labor to troubleshoot a $25 part!)

    Mercruiser branded elbows/risers/manifolds are about $1000 or so an engine IIRC. Install time can vary, depending on (1) if bolts are rusted on and (2) honesty of the mechanic.

    The real issue with the manifolds / risers is if they develop a leak from the water side into the exhaust: you could end up getting water back into the engine which would give you an opportunity to repower. . . .
     
  15. Mike

    Mike New Member

    62
    May 29, 2007
    Middle River, MD
    My engines are FWC. My problem my be that they are not getting enough water while underway. I replace impellors every other year whether they need it or not so I don't believe that is a problem. Heat exchangers were cleaned 1 1/2 years ago, and they actually didn't even need it.

    It will be interesting when I go back in this spring and I pay a little more attention to it. While on the hard I did poke a few barnacles out of the water pickups but nothing crazy.

    Is there a way to increase water flow? Being I only steam under load it makes me think that could be an issue. I have no steam at idle or lets say below 2500 rpms, also no "sweet" smell of antifreeze burning.
     
  16. dancer3402000

    dancer3402000 New Member

    12
    May 4, 2009
    look into dancer3402000 for information.
    search for white smoke.
    maybe it helps
     
  17. flarepoman

    flarepoman Banned

    390
    Jul 18, 2008
    More idiots here to
    boatless
    boatless
    Had the same problem 2 weeks ago. Raw water impeller was bad. Testing equipment-Home depot.get clear hose same sise and a T fitting, take the hoses off the risers put the test hose on and put a garden hose on that. Presto NO steam!! Before that check the strainers and the pick up under the boat. New impeller took 15 minutes to change.
    Rick

    1989 searay sundancer 454 330HP
     
  18. swift1

    swift1 New Member

    33
    May 13, 2009
    Puget Sound
    290 Sundancer 1995
    Single 454 Merc/BravoIII
    Around puget sound it is often a thousand each side risersn manifolds, maybe an elbow with labor. written the check on a couple mercs.
     

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