455 water leak
+ Reply to Thread
Results 1 to 4 of 4

Thread:
455 water leak

  1. #1
    Junior Member
    Join Date
    May 2009
    Posts
    2

    Default 455 water leak

    I have a 73 spectra 18 / 455 390 horse that has clean water leaking out from the passenger side valve cover. Where is this water leak likely to be originating from? been reading alot of blogs and there seems to be alot of answers. oh , berkley jet with a meirsch preloader, do have a 40 psi pressure reducer in line, no oil in pan , just on the valve train both sides. water dripping was visible at 4500 rpm and was not at any lower rpm. Hardin marine snails, motor is basically stock , we did a rebuild on this engine about 5 yrs ago and the boat is rarely used. last summer the pan did fill up wtih water and we did a clean out and installed new valley pan for the intake, replaced exhaust manifold gaskets with copper gaskets this time. Have yet to do a comp. test.

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    JWM
    JWM is offline
    Boat Test GURU JWM's Avatar
    Join Date
    Dec 2007
    Location
    Santa Ana, CA
    Posts
    516

    Default

    40 psi on your Olds is high in my opinion. See if you can drop it down to 30 PSI. Now for the trick question. The water on the top end of the engine is solid drops of water or mixed with the oil??? If it is a solid drop of water that indicates condensation. If it is mixed with the oil you should have oil and water on your dip stick..

    JW
    Sales & Service! V-Drives, Outdrives, Jet-Drives, MerCruiser, and Mercury Racing Parts.
    -Performance Engine Building-714-540-8908

  4. #3
    Senior Member hellnback's Avatar
    Join Date
    Oct 2010
    Location
    Lake Dallas TX
    Posts
    746

    Default

    I put a 15 psi valve with dump at the pump ... no more gasket blowing
    It may be OLD ,it may be Slow ... but at least it's MOBILE !!!

  5. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  6. #4
    "Mad" Member Jet Mad's Avatar
    Join Date
    Dec 2008
    Location
    Cape Town, South Africa
    Posts
    769

    Default

    Quote Originally Posted by hellnback View Post
    I put a 15 psi valve with dump at the pump ... no more gasket blowing
    You do not want any more than 15psi on the Olds water system.

    Fitting a pressure relief valve will keep the pressure constant in the system.

    Get rid of the old valley pan and install proper marine grade head gaskets and intake manifold gaskets. It will save you a lot of $ down the line.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	IG-505-GR -Marine Intake Gaskets.gif 
Views:	101 
Size:	16.2 KB 
ID:	112835  
    Attached Images Attached Images  


    Titan H2O Submersible Android Phone

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Please select your insurance company (Optional)

Log-in

Digg This Thread

Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •  
 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95