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Marine power 5.7 has major oil leak

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  • Marine power 5.7 has major oil leak

    I have a major oil leak in my 2011 Marine Power 5.7 vortec engine. I was crusing along at 3500 RPM and noticed my oil pressure drop very quickly. Turned off motor and then noticed a lot of oil in the bilge. Im talking quarts. Got it home and cleaned up all the oil.
    Re-filled the oil and did not see any leaks after filling but not running the engine
    1. Started the engine but it only got to 20 psi in pressure where nornmally its between 40-60.
    2. Once again lots of oil in bilge
    3. Oil pressure sender and attached hobbs switch had no oil leak
    4. Remote oil filters had no leaks nor did the hoses.
    5. Oil cooler has no leaks
    6. Could not see any oil around the intake manifold
    The oil seems to coming from behind the engine. Unfortunately, Im thinking it’s the rear seal.
    My question is this, is there anything else I could be missing? If it’s the rear main seal, I know I have to pull the motor but not sure how big a job replacing the seal is. Any input would be appreciaited before I go through the trouble to pull the motor.
    Last edited by Billnet; May 17th, 2017, 11:29 AM.

  • #2
    Could be the oil passage plugs working out. Could be core plug at back of cam bore, could be dizzy gasket missing.

    You may have to pull motor to find the leak
    1988 Cruisers Rogue 2420 -VP 290 DP now powered by custom 468 - http://forums.iboats.com/forum/owner...988-rogue-2420

    Past Boats
    1970 Wooster Hellion - Merc 9.8
    2002 SeaRay 190BR - 5.0 - A1G2 - "Cheasheads in Paradise"
    1984 Avanti 170DLI -3.0 stringer- "Ship Happens"

    What’s behind you doesn’t matter.Enzo Ferrari


    • #3
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      Ended up being the hose from my remote oil filter to the oil filter adapter. The leak was directly under my bellhousing facing aft. Could not see it until I pulled the motor up. Hose was split and brittle.