Oil Pressure Issue

Discussion in '94-95 5.0 - Specific' started by Bub, Mar 24, 2015.

  1. Bub

    Bub Active Member

    Messages:
    535
    Likes Received:
    15
    Joined:
    Mar 16, 2012
    Location:
    Pistakee Highlands
    Okay, so about the car its a 94 302, tfs 1 cam windsor jr heads and an explorer manifold. Maybe 1,000 miles on the build. (probably less) Ive had an issue with the stock oil pressure gauge reading low or 0. So today I did an oil change and swapped in a mechanical. The Oil filter was ****ed. and now after driving around a little bit, the mechanical gauge, reads around 5psi (somtimes lower) at idle and then between 10-25psi. while driving. Now the motor has no knocks or noises (other than a bit of rocker chatter) and when i pull the oil cap everything appears to be well lubricated. I assume the oil filter could either be a freak incident or way too much oil pressure. but then why is the gauge reading so low??

    [​IMG]
     
  2. Michael Plummer

    Michael Plummer Active Member

    Messages:
    434
    Likes Received:
    19
    Joined:
    Feb 20, 2007
    Location:
    Brockton, MA
    What weight engine oil are you using?
     
  3. Pack Rat

    Pack Rat New Member

    Messages:
    21
    Likes Received:
    0
    Joined:
    Mar 18, 2015
    Looks like the relief valve stuck in the pump and blew the filter. And now it is stuck and dumping pressure. Dont drive it. Drop the pan and take the pump apart. Check one rod and one main also.
     
  4. Bub

    Bub Active Member

    Messages:
    535
    Likes Received:
    15
    Joined:
    Mar 16, 2012
    Location:
    Pistakee Highlands
    Will that cause the gauge to read low?
     
  5. Bub

    Bub Active Member

    Messages:
    535
    Likes Received:
    15
    Joined:
    Mar 16, 2012
    Location:
    Pistakee Highlands
    10w30
     
  6. Michael Plummer

    Michael Plummer Active Member

    Messages:
    434
    Likes Received:
    19
    Joined:
    Feb 20, 2007
    Location:
    Brockton, MA
    Normally when the relief valve gets stuck pressure goes up and you should be able to read the higher pressure on the gauge. But you're reading low oil pressure which could be bearing wear on your engine internals (main, rod and cam). I have no idea on how you setup your mechanical oil pressure gauge but I'm going to assume it's setup correctly. Not sure how many miles are on your engine or how good or bad your maintenance schedule is but it just may be time for a rebuild.

    As a rule of thumb, I like at least 20 psi at hot idle and then a 10 psi increase for every 1000 rpm increase.
     
  7. Bub

    Bub Active Member

    Messages:
    535
    Likes Received:
    15
    Joined:
    Mar 16, 2012
    Location:
    Pistakee Highlands

    it is in the stock location, and nylon tubing ran to the gauge avoiding the headers. I really don't like the 90 degree sweep it is, and will be swapping in a 270 to get more accurate numbers.
     
  8. Bub

    Bub Active Member

    Messages:
    535
    Likes Received:
    15
    Joined:
    Mar 16, 2012
    Location:
    Pistakee Highlands
    Update on this, swapped in a different gauge just to make sure that wasn't the issue, and this one reads 20-25psi at cold idle. will most likely take it up to operating temp to see what it does
     
  9. kb1982

    kb1982 Active Member

    Messages:
    591
    Likes Received:
    4
    Joined:
    Aug 10, 2013
    Location:
    Kentucky
    Cut the old filter open and inspect it for metal.
     
  10. whiplash473

    whiplash473 Moderator Staff SN95 Supporter

    Messages:
    12,251
    Likes Received:
    1,205
    Joined:
    May 12, 2012
    Location:
    Northern IL
    Change from 10w30 to 5w30. Also, I know it's a stupid question and I know you're smarter than this, Joe, but you have the correct amount of oil in, right? Oil pressure can drop when oil level gets low.

    There's no need for our cars to have 10w30 where we live especially since we really only run them in the summer.
     
  11. Bub

    Bub Active Member

    Messages:
    535
    Likes Received:
    15
    Joined:
    Mar 16, 2012
    Location:
    Pistakee Highlands
    Yeah, oil level is fine. It's funny you say go back to 5w30 I've been talking to a few tech buddies I know and they're surprised I'm not running 20w30 because of the cam. As far as the filter goes there was some metal shavings but nothing I felt to be concerned about. It's still barely 1000 since the top end swap. However no metal in the oil that I drained
     
  12. Rallim

    Rallim Active Member

    Messages:
    730
    Likes Received:
    21
    Joined:
    May 5, 2011
    Location:
    Bellingham, WA
    20w30?
     
  13. Tony Corley

    Tony Corley New Member

    Messages:
    68
    Likes Received:
    0
    Joined:
    Mar 17, 2015
    Actually, the first number, (5w or 10w) specifies the oils cold temperature, cold start performance. The lower the number, the better the oils cold temp/cold start performance. In other words, changing from 10w30 to 5w30 is not going to help his issue. The 10w actually means it is for warmer temperature. Once the oil reaches 100 degrees C, they are both the same viscosity. (30w). Thicker oil may pick up your pressure (20w50), but it's only masking a problem. 10w30, (or 5w30 for that matter) will give you proper oil pressure if everything else is correct. When you are installing the gauge, are you using a different line? (Mechanical gauge, correct?) Make sure that the line is not kinked or pinched anywhere, and the fitting coming out the block doesn't have any restrictions. If all that checks out, and oil pressure stays the same, (and it is full of oil as specified earlier), then you need to pull it out and check everything. Make certain the pickup is sealed to the pump and not sucking air between the 2, and also the correct height in the oil pan. The start checking bearings and clearances.
     
  14. MikeA

    MikeA New Member

    Messages:
    5
    Likes Received:
    0
    Joined:
    Jan 11, 2015
    Location:
    Owasso Oklahoma
    It may have had a stuck pressure relief in the pump, and that is what ballooned the filter, but also popped out an oil galley plug. I have seen low pressure when the plug under the intake in the rear of the valley popped out or was left out and also the one behind the dist. That one is easy to see, just pull the dist and use a mirror or turn the pump and watch down the hole. The other one you will have to pull the intake. I would check the bottom end just for the piece of mind. At the very least numbers 3 and 7 rods. They seem to be the first ones to go. If it was mine it would come out and stripped to the last bolt. Good luck.
     
  15. Pack Rat

    Pack Rat New Member

    Messages:
    21
    Likes Received:
    0
    Joined:
    Mar 18, 2015
    Your relief valve is spring loaded to control pressure. You had to have had High pressure to blow that filter.
     
  16. Bub

    Bub Active Member

    Messages:
    535
    Likes Received:
    15
    Joined:
    Mar 16, 2012
    Location:
    Pistakee Highlands
    Okay mechanical line is fine, stock location no kinks or anything. We tried a quart of trans fluid to try and free up the relief valve. When we started I could rev it to 5 grand and the gauge would blow well past 100psi after 30 min. Warm oil pressure seemed go settle at 15 psi my idle is set around 750 and the next day cold was around 25psi. Holding the rpms seems to stay truer to 10psi per 1000rpms. I'm going to change the oil now and see from here. These numbers don't seem all that terrible from what I've read. I'm considering a thicker oil and calling this OK until winter where it'll most likely get pulled and well . . .most likely I'd throw an LS motor in it :)
     
  17. Bub

    Bub Active Member

    Messages:
    535
    Likes Received:
    15
    Joined:
    Mar 16, 2012
    Location:
    Pistakee Highlands
    Also for a few reasons, I pulled the manifold last night and while it was off I inspected the lifters pushrods and lifter valley, also looked down the oil galley holes for excessive cam wear, everything looks great.
     
  18. Tony Corley

    Tony Corley New Member

    Messages:
    68
    Likes Received:
    0
    Joined:
    Mar 17, 2015
    Cam lobes with a roller lifter are not going to tell you much, they will be one of the last things to show wear. You obviously have an issue, and there are only 2 ways to find it. Tear it down, or keep driving it. Either way, the cause of the problem will show up, lol.
     
  19. Bub

    Bub Active Member

    Messages:
    535
    Likes Received:
    15
    Joined:
    Mar 16, 2012
    Location:
    Pistakee Highlands
    Agreed. It was nice to be able to rule out a dropped lifter or something similar. Going to work on assembling everything and then changing the oil and seeing where it sit
     
  20. JKady

    JKady Active Member

    Messages:
    266
    Likes Received:
    0
    Joined:
    Mar 20, 2013
    Location:
    Graham, WA
    You should have way more than 25psi cold. I think a few of the replies are on the right track, your relief valve stuck and did that to the filter then blew a galley plug. If it were my car I would pull it and tear the engine down, as much as i know you don't want to there is something very unhappy inside your engine and it's going to break stuff if you keep running it.