Announcement

Collapse
No announcement yet.

Oil pressure sender omc 5.8

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Oil pressure sender omc 5.8

    My oil pressure reads almost 70 psi with engine shut down. I read stories about faulty oil pressure sending units. I ordered a new Sierra 18-5899 which should be same as the original 3847532.
    Fresh out of the wrapper I tested it, same reading as the old. I held them in series and pressure indication drops to about 20 if I short out the wire it goes up to infinity. Disconnected it reads 0.
    From reading: the higher the resistance, the lower the pressure value. In that regard mine is correct. Is there a way:that my gauge is wrong, can it be adjusted? It is an 89 Faria gauge.

    #2
    Something going on electrically me thinks, should read zero when the engine is shut down. A mechanical gauge plumbed in at the engine will give you something more realistic to compare to
    Dave
    Edmonds, WA
    "THE FIX"
    '93 2556
    Carbureted 383 Vortec-Bravo II 2.0:1 18 1/4x19 P

    The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
    Misc. projects thread
    https://www.baylinerownersclub.org/f...56-gctid789773

    Comment


      #3
      No oil pressure should give reading of zero. Too much resistance should read near zero. According to specs 220 Ohm =5 psi 100 Ohms= 50 psi.
      A bad wire /connection with high resistance should read near zero.
      The new one I hooked it up to the wire, and the other side jumped to negative on the battery it read almost 70 psi. Same as the old one with just they key to "on". Engine is not running, this new sender has never seen an engine (or oil) yet. That is the same reading as the old sender. I tried cleaning the contact on the gauge, that did nothing. Putting the two senders in series (doubling the resistance to 440 ohms brought the reading down to about 20 psi.
      I cannot find anywhere what the internal resistance of the gauge is. No info anywhere about possible adjustments to the gauge.

      Comment


        #4
        I took the gauge out, attached it to the pressure sender and a small 12V battery. It is doing the same. I guess the gauge is bad. There is no info about resistance values between the coils that make up the instrument.
        Now I am looking for a black-faced Faria CS0263.

        Comment


          #5
          I had a similar issue with a tach. Insects got inside the unit and they put something crusty across the PCB tracks. I cleansed the board with contact cleaner and the tach functioned fine for years. May be worth opening the gauge to inspect?

          Comment


            #6
            FYI..... and this may not apply to your issue.

            The oil pressure and temperature gauge sending units are specific for single station and for dual stations.
            The wrong sending unit will give an incorrect gauge reading.


            However, I think that you may be on the right track with the idea that the gauge has gone bad.


            Take a look here.............


            https://www.google.com/search?q=fiar...w=1252&bih=686


            ............ Or here..........

            https://www.google.com/search?q=fiar...h=686&biw=1252

            https://www.google.com/search?q=fiara+blackface+oil+pressure+gauge+black-faced+Faria+CS0263.&tbm=isch&hl=en&sa=X&ved=2ahUKE wjXi93Q2pPtAhUWqZ4KHYOrDL8QBXoECAEQFA&biw=1237&bih =686
            Rick E. Gresham, Oregon
            2850 Bounty Sedan Flybridge model
            Twin 280 HP 5.7's w/ Closed Cooling
            Volvo Penta DuoProp Drives
            Kohler 4 CZ Gen Set

            Comment


              #7
              This is my old one:
              Attached Files

              Comment


                #8
                Originally posted by Metrodriver View Post
                No oil pressure should give reading of zero. Too much resistance should read near zero. According to specs 220 Ohm =5 psi 100 Ohms= 50 psi.
                A bad wire /connection with high resistance should read near zero.
                The new one I hooked it up to the wire, and the other side jumped to negative on the battery it read almost 70 psi. Same as the old one with just they key to "on". Engine is not running, this new sender has never seen an engine (or oil) yet. That is the same reading as the old sender. I tried cleaning the contact on the gauge, that did nothing. Putting the two senders in series (doubling the resistance to 440 ohms brought the reading down to about 20 psi.
                I cannot find anywhere what the internal resistance of the gauge is. No info anywhere about possible adjustments to the gauge.
                Have you tried a temporary new wire from the sender to the gauge? Could the original wire be connected to something it’s not supposed to be along it’s path?
                just a thought
                Dave
                Edmonds, WA
                "THE FIX"
                '93 2556
                Carbureted 383 Vortec-Bravo II 2.0:1 18 1/4x19 P

                The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
                Misc. projects thread
                https://www.baylinerownersclub.org/f...56-gctid789773

                Comment


                  #9
                  I took the gauge, the sender and a small 12 V battery to the kitchen table, same results. It shows 80 psi. Same as in the boat.
                  Attached Files

                  Comment


                    #10
                    Originally posted by Metrodriver View Post
                    I took the gauge, the sender and a small 12 V battery to the kitchen table, same results. It shows 80 psi. Same as in the boat.
                    What happens when you remove the wire from the sender?
                    1997 Maxum 2400 SCR 5.7LX Bravo II

                    Mike

                    Comment


                      #11
                      Goes to its dead spot, right on top of the word oil.

                      Comment


                      • Metrodriver
                        Metrodriver commented
                        Editing a comment
                        Actually depends on which wire, removing the ground makes it go little higher

                      #12
                      The gauge is defective.
                      1997 Maxum 2400 SCR 5.7LX Bravo II

                      Mike

                      Comment


                        #13
                        For those of you who have a 12 vdc ground connection, make sure that the grounding rod penetrates the earth by at lest 8 feet.


                        Click image for larger version  Name:	12 volt battery ground.jpg Views:	0 Size:	54.2 KB ID:	605642

                        If your boat is moored, and if you do not have access to earth, here is a fully portable option for you.

                        Click image for larger version

Name:	12 volt portable battery ground.jpg
Views:	18
Size:	28.0 KB
ID:	605648

                        I know...... I know......... my pet peeve!


                        .
                        Rick E. Gresham, Oregon
                        2850 Bounty Sedan Flybridge model
                        Twin 280 HP 5.7's w/ Closed Cooling
                        Volvo Penta DuoProp Drives
                        Kohler 4 CZ Gen Set

                        Comment


                          #14
                          Maybe drag it 8 feet below the waterline
                          Dave
                          Edmonds, WA
                          "THE FIX"
                          '93 2556
                          Carbureted 383 Vortec-Bravo II 2.0:1 18 1/4x19 P

                          The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
                          Misc. projects thread
                          https://www.baylinerownersclub.org/f...56-gctid789773

                          Comment


                          • 2850Bounty
                            2850Bounty commented
                            Editing a comment
                            Dave, I guess that would work.

                          • Metrodriver
                            Metrodriver commented
                            Editing a comment
                            Would anchor work?
                        Working...
                        X