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Weird oil pressure?

Discussion in 'The Garage' started by JeremyK5, May 21, 2003.

  1. JeremyK5

    JeremyK5 1/2 ton status Premium Member

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    What would cause my oil pressure to go up 10psi by letting off the gas? /forums/images/graemlins/confused.gif It happens at highway speed when the engine is under load and I let my foot completely off the gas. It goes from 20 to 30 psi. Average cruising pressure is 25psi, and idle is 5psi. This is a mechanical gauge, and I even checked it with 2 others.

    Any ideas?
     
  2. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Thrust bearings are bad. The crank in walking forward and back. Couple things can cause this. Installing the harmonic ballancer with a Hammer is a biggie. Torque converter not seated corectly and put a lot of presure on them when trying to bolt up the tranny. Pinched tranny lines causing a High pressure problem in the converter can also cause it. It pushes the converter hard against the crank.

    Might be able to fix it with a set of main bearings if the crank isn't in too bad of shape.
     
  3. kennyw

    kennyw N9PHW Premium Member

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    Not enough oil in the engine can also cause symptoms like this too. So check your oil if you havent already...
     
  4. JeremyK5

    JeremyK5 1/2 ton status Premium Member

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    Well, the oil is full&fresh, and no pinched tranny lines.

    The block was rebuilt by the PO about 15,000mi ago, I have no idea of the quality though.

    There aren't any knocking sounds, and I can easily spin the tires (35") around a turn, so right now the only symptom is the oil pressure.

    What I'm trying to say is- Is this something that has to be fixed right away, or can I put it off for a month or so without much risk of something drastic happening?
     
  5. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    I had a Legit rebuild motor do the same thing with about 50k on it. If the PO hammerd that ballancer on it does in the thrust bearings.
     

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