Hot oil Pressure fluctuation

Discussion in 'Engine & Drivetrain' started by SnowDrifter, Nov 21, 2018.

  1. SnowDrifter

    SnowDrifter Full Access Member

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    When engine is hot, I see some oil Pressure fluctuations. When cold, oil Pressure is steady.

    Oil level is OK. Using a 0w30 oil with the easier style (longer) filter. Engine otherwise doesn't make any unusual noises or exhibit odd behaviors.

    I have an idea I'd a bunch of causes, but I could use a hand sorting as far as what's more or less likely. Come brainstorm with me

    2005 tahoe 5.3LT, 140k mi


    Video of issue:


    Ideas:

    Sending unit. Was replaced 2 years ago but that doesn't mean much.


    Cracked pickup tube. I'd think this would cause more of a no pressure situation, no?


    Boinked pickup tube o ring. Maybe? High steady oil Pressure when cold that increases linearly with rpm. This issue only occurs when hot

    Worn or cavitating oil pump. I could see worn, oil pump having difficulties when the oil is warm and thinner. Cavitating would strike me as odd given this occurs across the rpm range

    Worn bearings in engine. Don't think that would be likely. Seems to be that would cause a continuous low pressure, not fluctuating.

    Bad oil pump bypass valve. Seems to me I'd have an issue when cold as well, no?



    Other ideas?
     
  2. swathdiver

    swathdiver Full Access Member

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    Mine always bounces around at idle when hot. Cold and underway it is steady.
     
  3. SnowDrifter

    SnowDrifter Full Access Member

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    How about hot revved? Similar to the Pic?
     
  4. SnowDrifter

    SnowDrifter Full Access Member

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    How about hot revved? Similar to the Pic?
     
  5. swathdiver

    swathdiver Full Access Member

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    Yes, if the motor is revved up in park the pressure will increase some. It bounces around at idle because the rpms bounce around at idle. My single pattern camshaft (stock) has a little bit of lope to it even though BlackBear raised the rpms at idle by about 50.
     
  6. afpj

    afpj Full Access Member

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    Does 2005 MY call for 0w-30? Just throwing it out there but as the engine ages and tolerances loosen, maybe it’s too thin? In theory when warm it oil should behave like 30w, but just throwing that out there. Based on your vid it only happens whe warm AND rpms up? Or happens warm and idle too. Partly clogged pickup screen? Although you would expect that can cause fluctuations in hot or cold. Well, that’s my bit for brainstorming, such as it is. Sorry can’t be more help.

    Btw, what program allows digital read of oil pressure? I don’t see anything in torque.
     
  7. afpj

    afpj Full Access Member

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    Does 2005 MY call for 0w-30? Just throwing it out there but as the engine ages and tolerances loosen, maybe it’s too thin? In theory when warm it oil should behave like 30w, but just throwing that out there. Based on your vid it only happens whe warm AND rpms up? Or happens warm and idle too. Partly clogged pickup screen? Although you would expect that can cause fluctuations in hot or cold. Well, that’s my bit for brainstorming, such as it is. Sorry can’t be more help.

    Btw, what program allows digital read of oil pressure? I don’t see anything in torque.
     
  8. afpj

    afpj Full Access Member

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    Does 2005 MY call for 0w-30? Just throwing it out there but as the engine ages and tolerances loosen, maybe it’s too thin? In theory when warm it oil should behave like 30w, but just throwing that out there. Based on your vid it only happens whe warm AND rpms up? Or happens warm and idle too. Partly clogged pickup screen? Although you would expect that can cause fluctuations in hot or cold. Well, that’s my bit for brainstorming, such as it is. Sorry can’t be more help.

    Btw, what program allows digital read of oil pressure? I don’t see anything in torque.
     
  9. afpj

    afpj Full Access Member

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    Does 2005 MY call for 0w-30? Just throwing it out there but as the engine ages and tolerances loosen, maybe it’s too thin? In theory, but just throwing that out there. Based on your vid it only happens whe warm AND rpms up? Or happens warm and idle too. Partly clogged pickup screen? Although you would expect that can cause fluctuations in hot or cold. Well, that’s my bit for brainstorming, such as it is. Sorry can’t be more help.

    Btw, what program allows digital read of oil pressure? I don’t see anything in torque.
     
  10. afpj

    afpj Full Access Member

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    Does 2005 MY call for 0w-30? I thought these call for 5 w-30 but I have 2002. Just throwing it out there but as the engine ages and tolerances loosen, maybe it’s too thin? In theory, but just throwing that out there. Based on your vid it only happens whe warm AND rpms up? Or happens warm and idle too. Partly clogged pickup screen? Although you would expect that can cause fluctuations in hot or cold. Well, that’s my bit for brainstorming, such as it is. Sorry can’t be more help.

    Btw, what program allows digital read of oil pressure? I don’t see anything in torque.
     
  11. afpj

    afpj Full Access Member

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    Does 2005 MY call for 0w-30? I thought these call for 5 w-30 but I have 2002. Just throwing it out there but as the engine ages and tolerances loosen, maybe it’s too thin? In theory, but just throwing that out there. Based on your vid it only happens whe warm AND rpms up? Or happens warm and idle too. Partly clogged pickup screen? Although you would expect that can cause fluctuations in hot or cold. Well, that’s my bit for brainstorming, such as it is. Sorry can’t be more help.

    Btw, what program allows digital read of oil pressure? I don’t see anything in torque.
     

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