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Technical SBF 302 Oil pressure help

Discussion in 'The Hokey Ass Message Board' started by 56MercMan, Sep 22, 2021.

  1. 56MercMan
    Joined: May 22, 2008
    Posts: 131

    56MercMan
    Member

    I have a 302 in my Mercury. Oil pressure was at 40ish psi. It dropped to 0. I pulled the line to the manual gauge and hooked up another gauge. Still 0.

    I pulled the distributor and put my drill on the oil pump rod and spun it in reverse very slowly. No movement of the gauge. I decided forget it and put the drill on full blast in reverse... After a second you hear a squirting noise and the gauge jumps up to 50ish. I slow the drill down and the gauge moves higher and lower with the speed of the drill. I hook up my manual gauge in the car and it works again. I go for a drive (About 12 miles) and the pressure remains 20-30 after warming up. Then all of a sudden it drops to 0 again. I shut it down and tow it home.

    Anyone have any ideas on what I need to check? I assume the screen in the pan is good because when the oil pressure is there it is high and all good. I am assuming the pump is working because the oil pressure is very good when working. Any ideas on blockage or anything I can check to find the issue?

    ford 302 is not something I am experienced with. Motorcycles and foreign motors I have worked on/rebuilt in the past.
     
  2. RmK57
    Joined: Dec 31, 2008
    Posts: 2,659

    RmK57
    Member

    Could be something in the oil pump itself internally.. Relief valve stuck or sticking open?
     
  3. greybeard360
    Joined: Feb 28, 2008
    Posts: 2,074

    greybeard360
    Member

    Sounds like the pickup tube is loose and sucking air as the oil is sent thru the motor or the tube has fallen off of the pump.

    You might overfill the motor by a quart or two and see if it still does it. If that seems to cure it, pull the pan and fix it.
     
    osage orange and VANDENPLAS like this.
  4. Old engine ?
    New rebuild ?
    Engine carboned / gummed up ?

    oil pump relief valve stuck, jammed, falling out ?
    A chunk of something floating around and plugging up your oil pressure line?
    Something in your pan plugging the pick up ?
    Pick up fell off / falling off ?
    Pick up dirty ?

    how hard would it be to pull off your oil pan ?

    could be catastrophic failure, you will need to take some stuff apart, starting with the oil pan.
     

  5. Try replacing the filter first....
     
  6. :rolleyes::oops::rolleyes::oops::rolleyes:

    K- keep
    I-it
    S-simple
    S- stupid .


    For the whopping 8 bucks that it is yes, a cheap or buggered filter could cause issues .
     
  7. oldiron 440
    Joined: Dec 12, 2018
    Posts: 3,299

    oldiron 440
    Member

    Did you check the oil?
     
    Deuces and 03GMCSonoma like this.
  8. BamaMav
    Joined: Jun 19, 2011
    Posts: 6,709

    BamaMav
    Member
    from Berry, AL

    Has a 351W do the same thing. Turned out the screen was nearly clogged. Debris from oil seals and poor oil changes. Cleaned the pan, screen, and pump and it was fine.
     
  9. Zookeeper
    Joined: Aug 30, 2006
    Posts: 1,042

    Zookeeper
    Member

    If the motor has never been apart, the original timing gears were plastic coated and the plastic comes off and clogs the oil pickup screen.
     
    Deuces likes this.
  10. Is the oil pump rod still got sharp corners on both ends? I have seen them get rounded off before.
     
    finn and VANDENPLAS like this.
  11. 56MercMan
    Joined: May 22, 2008
    Posts: 131

    56MercMan
    Member

    Thanks for replys so far.

    Motor is fairly new/cleaned up. It has been apart before.
    @irishsteve - The rod does have sharp edges and no rounding. Same with the bottom of the rotor
    @oldiron 440 - It does have fresh oil. Only a couple 100 miles on this oil change. I checked the oil after losing pressure and she is topped off.
    @Crazy Steve and @VANDENPLAS - I have a new filter in the garage. I will swap that and see if that changes anything first. The oil pressure issue has been during the same filter.

    The motor looks really clean inside. No gumming in the heads or anywhere that I have seen when taking it apart. The pushrods and lifters all look extremely clean.

    I will try the filter first and see if that changes anything (Simple 5 minute try). If not I will see how hard it is to drop the pan and see what I can find. Not sure if there is a crossmember in the way or any of that right now while at work. Thanks for the advice so far everyone.
     
    Deuces, Boneyard51 and VANDENPLAS like this.
  12. Check the pump sounds like the bypass is sticking open. Sometimes they get crap in 'em and that can cause the bypass to stick open.

    Now sage advice, when you change the pump by a Melling. They make a damned good pump.
     
    seb fontana, fauj, Deuces and 2 others like this.
  13. Definitely all above are good answers with the oil filter being the cheapest and less invasive. I had a 302 in an OT Merc years ago with similar circumstances and it also was a plugging oil pick up screen. The remedy was pull the engine and clean the pan pick up tube and screen and for good measure replaced the original factory oil pump with a Melling.
     
    fauj and Deuces like this.
  14. I pulled the pan on an OT mud truck while I was in Mexico. It had intermittent oil pressure. It also had a label from some car part (I think from the control mod) floating around in the pan. It was an older truck (miles older) so I replaced the pump while I was in there. But I am sure that the paper was the culprit and I have no idea how it got in there.
     
  15. 56MercMan
    Joined: May 22, 2008
    Posts: 131

    56MercMan
    Member

    Well you hit the nail on the head with that post
     
    Deuces likes this.
  16. 56MercMan
    Joined: May 22, 2008
    Posts: 131

    56MercMan
    Member

    Finally got the pan off and look what I found:

    I know what they are... any guesses before I show you?

    Pic of the pickup:
    20220427_174815.jpg

    Pic of yhe bottom of the oil pan:
    20220427_175142.jpg
     
    VANDENPLAS likes this.
  17. What the hell….how…
     
    fauj and VANDENPLAS like this.
  18. 2Blue2
    Joined: Sep 25, 2021
    Posts: 378

    2Blue2

    Rock Auto business cards?
     
    sunbeam, fauj, Deuces and 1 other person like this.
  19. Dedsoto
    Joined: Jan 7, 2014
    Posts: 320

    Dedsoto
    Member
    from Australia
    1. Aussie HAMBers

    someone's idea of sticking a magnet in the pan, and only having an excess of fridge magnets?
     
    SS327, fauj and Budget36 like this.
  20. Clydesdale
    Joined: Jun 22, 2021
    Posts: 177

    Clydesdale
    Member

    wow!!! thats next level!!!!

    good find :D
     
    Deuces likes this.
  21. Deuces
    Joined: Nov 3, 2009
    Posts: 23,753

    Deuces

    Gee... I wonder who built that motor????.....
     
    fauj likes this.
  22. MO_JUNK
    Joined: Jan 22, 2006
    Posts: 1,197

    MO_JUNK
    Member
    from Rolla, Mo.

    Excellent thread. Many great ideas presented here.
     
  23. Budget36
    Joined: Nov 29, 2014
    Posts: 13,174

    Budget36
    Member

    So what are the actual pieces? Are they magnets like Dedsoto mentioned, or ??
     
    seb fontana, fauj and Algoma56 like this.
  24. wheeltramp brian
    Joined: Jun 11, 2010
    Posts: 2,556

    wheeltramp brian
    Member

    Yep those are RockAuto magnets that they give you when you order parts for your fridge
     
    SS327 and osage orange like this.
  25. jimmy six
    Joined: Mar 21, 2006
    Posts: 14,801

    jimmy six
    ALLIANCE MEMBER

    Unbelievable. Everyone knows they go on the outside …
     
  26. Charlietruck62
    Joined: Apr 2, 2019
    Posts: 58

    Charlietruck62

  27. 56MercMan
    Joined: May 22, 2008
    Posts: 131

    56MercMan
    Member

    Yup. You guys got it. They are rock auto collector magnets that used to look like this:

    [​IMG]


    The motor was purchased off a guy on craigslist. Started ran and worked well. Looks like my moms friend never really inspected it before putting it in my car. The magnets broke down after a little driving. The hot cold and soaking in oil broke them down.

    If I would have done it I would have dropped the pan and did a little inspecting. Not complaining, still really happy that he and my mom surprised me with getting my car running and on the road.
     
  28. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 6,250

    Ebbsspeed
    ALLIANCE MEMBER

    Rock Auto sells fridge parts?
     
  29. finn
    Joined: Jan 25, 2006
    Posts: 1,280

    finn
    Member

    Yup. I got the wiper blades for my Fridge from Rock Auto.

    Didn’t put the magnets in the pan, though.
     
    SS327, Beanscoot, Dedsoto and 3 others like this.

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