Bearhawk Aircraft Bearhawk Tailwheels LLC Eric Newton's Builder Manuals Bearhawk Plans Bearhawk Store

Announcement

Collapse
No announcement yet.

High oil pressure on Lycoming IO360

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

  • High oil pressure on Lycoming IO360

    My cruise pressure runs in the low 70’s . Today the pressure was normal on takeoff about 15 minutes into the flight I got a light indicating high oil pressure. The pressure was fluctuating between 88 and 91. I cleaned the oil pressure relief and blew out the 2 oil galleries. During taxi after doing the previous an application of full throttle the pressure was 95 to 97. Tomorrow I will change the oil filter. Can anyone suggest any thing else that I can do if changing the oil does not solve the problem.

  • #2
    Check your sensor to make sure it hasn’t gone bad. Oil pressure sensors are sensitive to vibration and can go bad if mounted on the engine. They need to be isolated from the engine case by mounting on the engine mount or firewall and connected to the sensor port with a flexible hose via an orifice installed in the sensor port.

    Comment


    • Wmilbauer
      Wmilbauer commented
      Editing a comment
      Thanks, I have a second sending unit that I can switch out , I will give it a try

  • #3
    And to that, make sure there's still a good ground after you remote mount it. I had my first sensor go bad at 10 hours because I mounted it directly to the case. But it uses the case for ground, so you do have to run an extra wire or find conductive hose.
    It was reading fine at everything but full power, somehow it'd fail open at higher power settings, which to the device reading the resistance means very high pressure.

    Comment


    • #4
      I have my first airplane oil pressure sender remote mounted. I have mounted VDO oil pressure senders dozens of times to dozens of engines, directly to the engine. I have a 33 year old VW van, with a 28 year old Subaru EG33, and a 18 year old VDO sender and gauge that still works perfectly. Airplane engines vibrate more than car engines so maybe remote mounting them is a good idea. I did it on my kit because it seems to be "airplane convention". The senders do use the case for ground. I would first test to make sure the ground connection to the engine is good (with a multimeter).

      The other option is my personal technique, which involves replacing parts, starting with the most expensive first. I wish I could break myself of this but it seems to be ingrained in my nature. Using that logic, historically I would replace the engine first, as I would assume that was the problem.
      Last edited by svyolo; 05-15-2020, 09:26 AM.

      Comment


      • #5
        Well I solved my high oil pressure problem. It was the oil filter.The filter failed to go into the bypass mode which apparently lead to the high oil pressure. I cut the filter and there was no metal so all is good. 29 hours on the filter.

        Comment


        • #6
          Thanks for posting back the find, what brand and model filter?

          Comment


          • #7
            How interesting. Should the bypass be opening in these cases? Seems like it should only be opening when the oil is really cold or the filter is blocked?

            Comment


            • Wmilbauer
              Wmilbauer commented
              Editing a comment
              It was tempest AA48110-2 . I am going to talk to tempest on Monday and find out the details of the how the bypass works and when it should go into bypass. I will forward any information I receive. The Bypass relief valve TCM specs: 12 -14 psi but that really mean anything to me.

          • #8
            It is really disheartening when you think you know everything and then you find out that isn’t true. I talked to Tempest today and was told that the filter I have does not have the bypass capability. Now I have to figure out what the sequence of pressure adjustment and the filter are to verify if my problem was really the filter or it fixed the problem on its own.

            Comment


            • #9
              Well that's too bad, a smoking gun is always a reassuring thing. I've been in similar situations before and it's not fun. Please keep us updated!

              Comment


              • #10
                Originally posted by Wmilbauer View Post
                My cruise pressure runs in the low 70’s . Today the pressure was normal on takeoff about 15 minutes into the flight I got a light indicating high oil pressure. The pressure was fluctuating between 88 and 91. I cleaned the oil pressure relief and blew out the 2 oil galleries. During taxi after doing the previous an application of full throttle the pressure was 95 to 97. Tomorrow I will change the oil filter. Can anyone suggest any thing else that I can do if changing the oil does not solve the problem.
                Are you running a case mounted oil filter base, or a remote filter? If a remote filter, double check that the feed and return hoses are in the correct orientation. I saw a situation where a C-170 flew (literally) for years, with a remote filter plumbed reverse. On one, uneventful, flight - pressure dropped to zero. When the error was discovered, hoses were rerouted and never a problem again. We never could figure out why it behaved that way.

                Bill

                Comment


                • svyolo
                  svyolo commented
                  Editing a comment
                  Have you done any troubleshooting to make sure it isn't the sender or gauge? The fluctuating part makes me think electrical connection.

                • Wmilbauer
                  Wmilbauer commented
                  Editing a comment
                  It is a case mounted filter and I changed the sending unit
              Working...
              X