Low Oil Pressure at Idle When Warm

Discussion in 'Engine & Drivetrain' started by Austen Leach, Jan 17, 2020.

  1. Austen Leach

    Austen Leach Member

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    None of my local parts stores rent oil pressure testers. The only pressure gauges they have are compression and an electronic fuel pressure gauge
     
  2. Tonyv__

    Tonyv__ TYF Newbie

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    I might try this to see if my o ring is bad.. however after testing. Should I drain it back down to 6qts? I’ve always heard overfilling was bad for the engine but I don’t actually have any evidence to back that up
     
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  3. swathdiver

    swathdiver Full Access Member

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    Well, I thought so too with these engines but a fella on here was down on his luck and kept his over-filled for two years until he could afford to get it fixed.
     
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  4. SnowDrifter

    SnowDrifter Full Access Member

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    Overfilling is bad when the crankshaft dips into the oil and whips it into a foam.

    You can tell by running your rig for a few mins and quickly pulling the dipstick out to inspect while running.

    FWIW I run 7 quarts in mine. I run the long filter but it doesn't displace an appreciable amount. No aeration issues

    Edit: brain dump. Not sure about front or rear seals. IIRC they're primarily to guard against oil spash vs oil butting up against it. I suppose it could worsen a leak if there's a pool of oil sitting against the things, but then again, if it doesn't seal there, I can't see it sealing in general. And besides those points, if your running oil level is that high, your engine is trying to make a nice whipped topping out of your oil.
     
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  5. avalonandl

    avalonandl Full Access Member

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    Do NOT run overfilled it causes the oil to foam which is BAD.

    You can run maybe 1/2 quart high but 8-9 quarts is way to much.
     
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  6. Tonyv__

    Tonyv__ TYF Newbie

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    Are you saying I shouldn’t even over fill just to test the o ring theory? Or I shouldn’t overfill and leave it in the engine for a long period of time.
     
  7. avalonandl

    avalonandl Full Access Member

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    You can overfill it to test it but drain back down before driving.

    Oil that has foam in it is actaually air bubbles and will not provide consistent oil coverage on bearings.
     
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  8. Tonyv__

    Tonyv__ TYF Newbie

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    gotcha. Thank u for clearing that up
     
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  9. Austen Leach

    Austen Leach Member

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    I’ve got a little update/addition to this issue. Yesterday I drove to Arlington to pick up a 2/4 drop kit for my cousin’s truck. I checked my oil before I left and it was right in the middle of the crosshatching. I ran about 85mph the entire way there and back. Got in the Tahoe the next morning and started it up to run and grab some coffee and the dash read “check oil level”. Pulled the stick and nothing on it. I topped off the oil back to about 3/4 up on the crosshatching and crawled under the truck to ensure I didn’t have a massive leak somewhere. I have a tiny tiny rear main leak but nothing ever touches the ground and nothing is blown back on the transmission or anything. Also after I went to the coffee shop and went out and started the Tahoe I had a decent smoke cloud come out from the exhaust. I was in the shop for about 35 minutes and my windows are tinted extremely dark so I couldn’t really see the color of the smoke but I’m not losing any water and my oil doesn’t look milky or anything
     
  10. avalonandl

    avalonandl Full Access Member

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    Your sucking oil thru your pcv is my bet. At high speed cruising.
     
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