No oil pressure at idle!

Discussion in 'V-8 Buick Powered Regals' started by 455regalwagon, Mar 29, 2010.

  1. 455regalwagon

    455regalwagon Got tourque?

    i have a 83 regal estate wagon with a 455 from a 76 riviera.motor is rebuilt with a mild comp cam.it runs the balls going down the road with about 60lbs or more oil pressure but at an idle it drops to almost nothing and the lifters start to tick until i start moving again and everything is fine.anyone know what my fix is for this problem? thanks allot in advance..
     
  2. DaWildcat

    DaWildcat Platinum Level Contributor

    What are your main bearing clearances?

    Devon
     
  3. 455regalwagon

    455regalwagon Got tourque?

    no idea, i bought the motor already rebuilt...
     
  4. DaWildcat

    DaWildcat Platinum Level Contributor

    What viscosity oil are you using? Is cold idle pressure ok but dropping to zero when at temp?

    Devon
     
  5. 455regalwagon

    455regalwagon Got tourque?

    im running rotella oil and lucas right now to try and solve the issue but no luck...it only drops at idle when it gets up to temp.
     
  6. DaWildcat

    DaWildcat Platinum Level Contributor

    What viscosity did you try before and are trying now?

    Devon
     
  7. 455regalwagon

    455regalwagon Got tourque?

    i was running regular 10w 30 before but now im trying rotella diesel 15w 40 with lucas additive..
     
  8. DaWildcat

    DaWildcat Platinum Level Contributor

    Has it been like this since the rebuild or is it something that's gradually gotten worse?

    My first thoughts are excessive bearing clearances which can show the 11 psi per 1000 rpm the big blocks like to see, but can still result in low idle pressure. A worn oil pump is possible too. One thing that could be of help would be to remove the oil filter housing and remove the oil pump gears. You can inspect the gears, the thrust face of the housing and the oil pump pocket for scoring. If the pocket looks ok, you could try a new set of gears with the TA booster plate before taking any next steps.

    Maybe some others will have some different ideas.

    Devon
     
  9. 455regalwagon

    455regalwagon Got tourque?

    yeah its gradually gotten worse.so if i remove the filter housing i can get at the pump or do i have to remove the oil pan? thanks for your help..
     
  10. DaWildcat

    DaWildcat Platinum Level Contributor

    While I'm thinking of it, another thing to try is a different mechanical pressure gage just to rule out a gage problem.

    The oil pump gears will drop (or pull) right out with the filter housing off, so you won't have to worry about the pan.

    Also, it might not hurt to cut the filter open with some tinsnips to see if there are any telltale signs of bearing problems in the element.

    Devon
     
  11. 455regalwagon

    455regalwagon Got tourque?

    ok, thanks allot for your help!
     
  12. idahoskylark

    idahoskylark idahoskylark

    possible leak on the pickup tube in the pan
    5.3l chevy's have this problem gasket on p/u tube leaks causing to suck slight amount of air at idle ok at higher rpm they claim its no problem but hey its your motor and you have to listen to it
     
  13. bigdawg70

    bigdawg70 1984 Buick Regal

    Also depending on the filter you might see a low oil spike. If your not using one put a ac delco on if you have a stock pump and not high volume
     
  14. Bar50

    Bar50 Well-Known Member

    You can also put in an adjustable oil pressure spring cap and bump it up a little. You can pick up a new wear plate and gears at most auto parts stores the plate is the same as 3.8 buick. Slap a new set of gears and plate, covered in vaseline.
     
  15. 455regalwagon

    455regalwagon Got tourque?

    if i wanted to take the oil pump out and inspect it or even replace it is this a hard job?what is involved? do i have to take off the oil pan?which one should i buy? thanks:Dou:
     
  16. DaWildcat

    DaWildcat Platinum Level Contributor

    I though I already covered that. :Do No:

    Do you have a chassis service manual that covers a Buick 455?

    And an adjustable oil pressure regulator will do nothing for hot idle pressure.

    Devon
     
  17. 455regalwagon

    455regalwagon Got tourque?

    so i got a little update guys and i really apprieciate all the help.

    i didnt take out the oil pump assembly yet to inspect it but i did do a oil change today.

    i started out by using some 5 min. motor flush. how does everyone feel about that stuff?

    then i drained out the lucas/rotella diesel oil mixture.

    i filled the motor with kedall 20 50w oil as someone suggested.

    well now i have the same oil pressure as before ( 40-50lbs driving, 5-10lbs idling)

    now i have developed a loud ticking all the time and i mean LOUD!:Dou:

    it sounds like a lifter but not too sure, any suggestions? was it the flush? kendall oil? what do you use for oil?:confused:
     
  18. tom_gonzalez@ve

    tom_gonzalez@ve Well-Known Member

    Try a can of Rislone. It is probable that you collapsed a lifter when the oil pressure dropped low. Rislone will clean up the lifters and might eliminate that tapping. Failing that remove the rocker covers and run the engine at idle and see if all lifters operate properly. If you find a low one individual lifters can be replaced by removing the rocker arm assembly and pulling out the faulty lifter. Before installing the new lifter immerse it in engine oil and pump it up until a resistance is felt, then install it and button up the rest of the engine.
     
  19. Running

    Running Midwest Buick Mafia

    Not a fan of motor flush.

    Cut the oil filter apart and hope that ticking didnt fill it with metal.

    Compression test - leak down test.
     
  20. 455regalwagon

    455regalwagon Got tourque?

    yup,just got finished draining some oil out and added a can of rislone, the tapping went right away! thanks allot:beer
     

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