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Oil psi

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Me89'Jimmy, Jul 31, 2003.

  1. Me89'Jimmy

    Me89'Jimmy 1/2 ton status

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    i have a rebuilt 350 and the oil pressure always reads about 60 psi, is that normal and if not whats the recomended amount of oil to use
     
  2. monte0172

    monte0172 1/2 ton status

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    More details on this are needed!! 60 psi is a tad high in my opinion but it certainly wont hurt anything. how long ago was it rebuilt? It may still be getting broke in if its not to long ago.
     
  3. 75-K5

    75-K5 3/4 ton status

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    My 350 in my "race" truck runs about 45 at idle and well over 60 at cruising rpms.
     
  4. Confedneck

    Confedneck 3/4 ton status

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    60 is too high...should idle down around 15-30 or so...how recent is the rebuild?
     
  5. Me89'Jimmy

    Me89'Jimmy 1/2 ton status

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    its got 25 grand on it so far, it idles around 45 50 but the second i get on the gas it shoots up to sixty /forums/images/graemlins/thumb.gif
     
  6. Don

    Don 1/2 ton status

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    Sound's like a high volume oil pump to me. Or some object is holding the pressure relief valve closed in the pump itself.

    I had that problem with the 454. Installed rebuilt 454 in June, ran at 60 psi. hot, at speed, at idle it had about 40 psi hot.

    Then the first cool night in October, I started it up, and blew the rubber gasket out of the top of the oil filter, twice.

    Pulled pan, oil pump etc. Found a piece of maching debris, just a fleck, holding the pressure releif valve closed. /forums/images/graemlins/eek.gif
     
  7. o2bjimmy

    o2bjimmy 1/2 ton status

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    my oil pres. guage has been at 60 psi since i got it. 60 psi even when its not running /forums/images/graemlins/ignore.gif
     
  8. 88Silverado

    88Silverado 1/2 ton status

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    My 88 runs 60 while driving and 30 while idiling. It has over 100K on it. My other 350, which has about 3K miles idles about 15-20 and runs about 50.
     
  9. BlueKnight

    BlueKnight 1/2 ton status

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    when its bouncing off the cam lobes at idle in gear I have about 30psi on the freeway about 70 it will max out at 60psi. I did put some z max in it awhile ago and it gave me 10 more psi.
     
  10. bigblock44k5

    bigblock44k5 1/2 ton status

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    rule of thumb for a motor with some pep, you want 10psi for every 1000rpms you run minimum. redline at 5000rpms, you want 50psi and soforth.
     
  11. Hustler

    Hustler 1/2 ton status

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    60 psi is not that bad at higher rpms. Now if you have that much psi at an idle, then I might worry a little. It should drop at an idle. Mine is at 60 psi plus when cold and while driving. After it warms up it will drop between 30 and 45 psi at an idle.
     
  12. 77Jimmy

    77Jimmy 1/2 ton status

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    My 350 was rebuilt as well (at some point prior to me buying it)...when warm, I idle at 30psi, driving I'm around 50-55psi.
     
  13. dyeager535

    dyeager535 1 ton status Premium Member

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    If you are using stock gauges, it *is* possible to get the wrong sender. Not sure which does what anymore, but the diesel trucks had different senders/gauges, because they had 80PSI gauges.

    May not be your problem, but the wrong sender for the gauge will cause problems with the reading being inaccurate...it works, just the needle is in the wrong place. Example: A vehicle with a 60 PSI guage with a 60PSI sender, on an engine that puts out 30PSI, reads right in the middle of the gauge. If you put an 80PSI gauge in there without changing the sender, it too will be in the center, but read 40 instead of 30.

    Soo, I guess if you had an 80PSI gauge with a 60PSI sender, indicated oil pressure would always show higher than actual.
     
  14. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Don't trust an electric gauge. Put a mechanical one on it to find out the truth.
     
  15. 84_Chevy_K10

    84_Chevy_K10 Banned

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    [ QUOTE ]
    I did put some z max in it awhile ago and it gave me 10 more psi.

    [/ QUOTE ]

    No it didn't. That's simply your imagination. Oil additives are the biggest scam in auto parts today.
     
  16. 75-K5

    75-K5 3/4 ton status

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    I dunno, JeremyK5 put some Lucas Oil Stabilizer in his Blazer when we were on a semi-road trip and it noticeably increased the pressure. Gauges don't have imaginations.
     
  17. dyeager535

    dyeager535 1 ton status Premium Member

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    [ QUOTE ]
    Don't trust an electric gauge. Put a mechanical one on it to find out the truth.

    [/ QUOTE ]

    Read up on them. Electric gauges are every bit as accurate as mechanical when working correctly. Everything loses calibration over time, so judging stock gauges against new mechanical is not a valid argument. (not saying it was used as such, but used vs new doesn't mean the used one is worse when it WAS new)

    Not going to say that mechanical gauges aren't used anymore, but they are certainly much rarer in almost any application I can think of.
     
  18. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    were does an electrical guage lose calibration? the sender, guage, old wiring, all 3?
     
  19. dyeager535

    dyeager535 1 ton status Premium Member

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    Every single component can "lose" calibration.

    From my understanding/playing with these gauges, GM "tuned" them with the ceramic piece on the back of them, to make them as close as possible to correct.

    But, as with anything, corrosion and age will affect readings, although I've never had a gauge that was just "wrong". Broken completely and obviously yes, but "incorrect" (compared to other gauges swapped in) no.
     
  20. Calclips

    Calclips 1/2 ton status

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    Electronics lose calibration over time. Here at work in the lab we have to send everything that we use, from stopwatches to thermocouples to pressure sensors over to the metrology lab for calibration. Some pieces of equipment are rated to hold their cal for a year and others are shorter. We even have to send torque wrenches to the metrology lab for calibration /forums/images/graemlins/shocked.gif
     

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