Got a Oil pressure problem, kinda long.

Discussion in 'Troubleshooting & Diagnosis' started by Old School, Feb 14, 2003.

  1. Old School

    Old School Veteran Member

    1,954
    0
    Jul 8, 2001
    Arlington, TX
    Hi guys, I got this oil pressure problem in my 383 like you wouldn't believe and I need any input possible. Heres what it does.

    At idle, 25 psi, at cruiseing speed, 60 psi. It goes right up when I get up to speed, no roblem there. The probelm I have is when I step into it half wayish or full throttle, it goes down to 30 to 40 psi. If I stay into it until 3rd, it it down to like 25 psi. I can try to get into it slowly and it will still drop, if I let off a sec, it will come back up and then I step into it and it goes down again.

    Here's what I've done so far.
    Back in Nov. the problem started, so I replaced the pump to 3/8's off the pan(M55HV, melling). No good. Replaced the main and rod bearings, no good. Pluged the oil adapter bypass, replace the oil gauage, checked the dist shaft, ran an extra quart of oil, run a pcv set up, and all no good. I just got it back from the engine builder and it is a completly fresh block. Magnafluxed the crank, pressure tested the block, resized the rods, turned the crank .010 under, line honed the mains, honed the bores, new bearing all around, frezze plugs, all of it! Got the engine back in and running today and it is still doing the same thing! This motor has been in my camaro since april and haven't had this problem until last nov.

    I've had a few people tell me its my pan, why didn't it do it when I first got it in? Had people say its the high volume pump, but never had the problem before until last nov. I got a friend that has the exact same bottom end. I mean same pump, same oil pan even and he's not having this problem. So where's the problem? I can tell you this much, I'm not pulling this motor unless another ones replacing it. I'm stump! Sorry for the rage, but I'm to the very end of my nerves. I think that it. Help help help!!!!

    Thanks,
    Michael

    ------------------
    My 75 Camaro
    383 with AFR heads.
    Old School for life!!!

    [This message has been edited by Old School (edited February 14, 2003).]
     
  2. Joekool

    Joekool Veteran Member

    5,829
    14
    Feb 4, 2002
    Hollister CA USA
    What oil pressure tap location do you use for your guage? If your using the one on the front of the block its going to read the lowest oil pressure in the system because it is at the last place that see's pressurized oil. I would tap into the one at the back of the block and compare.

    Now if your already using the one at the back of the block by the dist than I would say you have problems.

    Did you use a new pickup tube? Your symptoms sound alot like a semi clogged pick up tube or some sort of blockage resricting oil flow at high rpms.

    ------------------
    70 Camaro Sport Coupe 350cid balanced, blue printed and running smooth.
    74 TA under construction 400cid bone stock.
     
  3. Old School

    Old School Veteran Member

    1,954
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    Jul 8, 2001
    Arlington, TX
    Ya, I am using the back outlet for my pressure reading. I did get a new pump and pick-up for the new motor. Thanks for the help.

    Michael
     
  4. tbill

    tbill Veteran Member

    1,712
    0
    Mar 5, 2001
    durhamville,ny,us
    have you tried a different gauge?

    did the oil pump p/u tube fit firm into the pump? [maybe it's moving around if it wasn't tight enough]

    did you put in new cam bearings? [maybe one is slightly off the mark]

    just throwing ideas out, trying to help.

    ------------------
    71 ss 350/4spd 69 nova 350/th350 www.americaniron.net
     
  5. Greg Mc

    Greg Mc Veteran Member

    1,198
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    Mar 18, 1999
    Hernando, MS
    wasn't someone on another thread having a similiar oil pressure problem and some were pointing to the type oil filter. what size and type of oil filter are you using.
     
  6. Old School

    Old School Veteran Member

    1,954
    0
    Jul 8, 2001
    Arlington, TX
    I have tried another oil gauage and am thinking about getting a new one to try again just to rule it out. I did get the cam bearings replaced. I got the pickup welded to the pump, and it was set to 3/8's depth off the pan. I use a AC delco oil filter, but went out today and got another brand just to rule out if its the filter that is goofing on me.

    Thanks alot guys for the input, like I said, I am up for any ideas. I have no more really.

    Michael
     
  7. LeighP

    LeighP Veteran Member

    1,082
    0
    Nov 29, 2002
    Sydney, Australia
    Are you using an electric guage? If so, have you changed the sender? If its a direct reading guage, try another one.
    If all else fails, try running a pint or more over full....see if that makes a difference.

    ------------------
    Regards,
    Leigh
    76 Trans Am
    70 Camaro RS/SS
    Sydney, Australia
    TA76400@hotmail.com

    [This message has been edited by LeighP (edited February 16, 2003).]
     
  8. rscamaro73

    rscamaro73 Administrator Staff Member

    I can only think of 2 things right now ( I just got up ) ......

    1) Change the type of oil. Go to a different viscosity, see if that changes anything. What kind are you using now anyways ??

    2) How are the oil drain-back holes in the heads ?? Maybe during the 'romps' the heads/valve covers are filling up and not flowing like normal.

    Just my 3 cents....
     
  9. Old School

    Old School Veteran Member

    1,954
    0
    Jul 8, 2001
    Arlington, TX
    I am using a mech oil gauage and checked if the sleeves were pinching the line, but it was fine. The weight of oil I am using right now is 30w. I was running 40w before the problem and it was the same. I am going to try 50w and another brand filter to rule out that. I've tried the 1/2 to 1 extra qaurt thing and didn't help. I haven't tried it with the fresh short block, but I will give it another try.

    On the drain back holes in the heads, I have AFR's and didn't have the problem before, so why would it do it now kinda thing? I'm pretty sure I didn't get a bad set of AFR's. lol When the pressure drops, its instant. So, I still got oil in the pan.

    I will do the heavy oil and different filter tomorrow and come back with the results. Anyother idea's? I'm taking all into consideration.

    Michael
     
  10. Joekool

    Joekool Veteran Member

    5,829
    14
    Feb 4, 2002
    Hollister CA USA
    Cut the old filter open and see whats inside. If its clogged up or full of metal you will at least beable to find out before its to late. If there isnt anything abnormal you will atleast beable to rule out a clogged filter or bearing problems.

    ------------------
    70 Camaro Sport Coupe 350cid balanced, blue printed and running smooth.
    74 TA under construction 400cid bone stock.
     

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