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Oil filters, all cars

Discussion in 'Gen 4 Prius Main Forum' started by Mr.Vanvandenburg, Apr 1, 2024.

  1. Mr.Vanvandenburg

    Mr.Vanvandenburg Active Member

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    I read a lot about oil filters lately and “efficiency” seems to be a key word to assess how good a filter is.
    I see bypass oil filters take a small amount of oil from the flow and pass it through a filter that can catch virtually every particle. The oil is said to be analytically clean. I take it zero particles over one micron or similar great filtration results are typical. This is all the time after the initial cleansing, which happens quite fast.
    So if the bypass valves are leakers, like on the higher end current Frams, or if the media shows pores open at 100x on Whip City Wrencher, what difference would it make? It’s nothing compared to a bypass filter where most of the oil is unfiltered, but the result is cleaner oil on the bypass filter. So the leaks and pores and “efficiency” rating seem meaningless.
    I was trying to be happy with my Fram Ultra current model, but then saw the light leak tests, or paths the oil will go through unfiltered. On the surface that seems not good.
     
  2. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    I've used middle-of-the-market oils and very cheap filters for all my cars going back decades, and the only engine I ever lost to lube issues was one that didn't even make use of a filter.
     
  3. Mr.Vanvandenburg

    Mr.Vanvandenburg Active Member

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    Very true. So I think the leaking bypass valves on Fram Ultra, most Champ Lab, and the Toyota oil filters won’t matter. Since a bypass oil filter “leaks” maybe 90% of the oil flow, and the other 10% filtered very well keeps the oil clean. But at first look, the leaking valves seem horrible.
    I think full flow filters should not be leaking oil unfiltered though, bad engineering. They aren’t meant to do that.
     
  4. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Consider the dynamics. It's not very easy to make a compact filter that can maintain full flow all the way down to -50°F startups, for example.

    In practice, plenty of cars are doing full-flow filtration when the oil is hot and the engine is at idle speed. Only when the tach goes up does the bypass open.
     
  5. AzWxGuy

    AzWxGuy Weather Guy

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    I can't speak as an authority on this, but isn't that the reason we do oil changes periodically? Oil holds contaminants in suspension until drained and replaced with fresh oil. The filter media is inserted in the pressurized lubrication system flow to capture any potentially damaging larger particles. I would have to take a look at an exploded view, but I think the pressure relief is integral with the engine components now instead of replaced every time you changed a spin-on cartridge.
     
  6. Mr.Vanvandenburg

    Mr.Vanvandenburg Active Member

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    Some engines have the bypass valve in the block but most have it in the filter. What I am writing about is the bypass valve not seating properly when it is closed.
     
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  7. Mr.Vanvandenburg

    Mr.Vanvandenburg Active Member

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    Searched and found this leakage test. The older Fram Ultra has the bypass valve gasket shown in the pictures. It seems they changed to no gasket. He did find a leaking bypass valve in the Wix xp, and said if the test shows such leakage it’s a fail, and no reason to even do an efficiency test. Sort of long I don’t know if I watched all of it. He could get to the important parts and skip a lot.
    I saw the Purolator had no leakage in the bypass valve.