Low/no Oil Pressure When Hot

Discussion in 'Fox 5.0 Mustang Tech' started by Exitium, Oct 12, 2013.

  1. So as some of you may know about a month ago I had my entire fuel system go out in the car... After a week poking and prodding I finally got it back up and running then 2 days ago as I was coming home from work everything went bad again, as I was downshifting getting ready to take a turn my car literally shut off, I coasted to the shoulder and started it right back up. This went on and off again for the whole 20 miles back home. Every Time I stopped the car or it idled to low my car would shut off, happened to look over at the cluster and saw I was getting almost no oil pressure.

    Fast forward to today. I wake up early this morning and start the car and it starts right up. Pressure went right to about 50-60 and it idled just fine. As the car sat there warming up the pressure slowly started to drop, 55...50...40 and it kinda just sat there for a few minutes. After about 10 minutes it dropped down to about 20 and the car began to act like it wanted to die. Though if I step on the gas and get it up to around 2k RPM the pressure jumps right back up to around 60. *There is now a slight knock/tick that can be heard coming from the driver side of the motor as well, this started the same time the oil pressure issue started.

    I am really looking for ideas hopefully to avoid the adventure I endured with the fuel system I ended up spending WAY more than I had to and I would like to work my way from the least expensive or most probable and just go from there.

    I am willing to take as many pictures videos or answer any questions you may have to help me with this matter. I am leaning towards the oil pump being the issue but again I am not a 100%, I would also gather the sending unit but it appears to be showing an accurate reading as far as I can tell. Especially since when it reads 50+ the car is running great and when it drops the car just shuts off.....
  2. Honestly I would say that 20psi or better when hot isn't bad. Are to going off the stock gauge ?
  3. It is not a stock gauge, and I would agree that 20 PSI would be great as well if my car wouldnt shut off while stopped at a light, stop sign or pretty much anytime my car is coming to a stop.
  4. 20 psi of oil pressure is not whats making the engine stall. the hot oil psi is probably falling along with the idle. you need to find out why the engine is stalling
  5. @Exitium
    Does your fuel pressure drop as it gets warm?
  6. @85rkyboby Yeah so far that is what I have noticed. When I start it up first thing in the morning and drive it to work while it is still cool I have no issues, No loss of power, no stalling and no issue with the oil pressure. Yet 2 days in a row when I get back in my car at mid day, and drive about 5 miles all of these issues start happening that I described in my OP.
  7. What's your fuel system setup? @Exitium
  8. Your fuel pump could be shutting down after it warms up.
  9. @85rkyboby So I just replaced the entire fuel system less than 2 months ago because I had a similiar issue back then. But this is what I have for the whole car and I will highlight the fuel components.

  10. @85rkyboby Also I want to apologize, I did not read your post correctly last night until I looked this morning. I have not noticed anything with the "Fuel Pressure", I saw the word pressure and assumed you were asking me if I noticed a drop in "Oil Pressure" when it gets warm.

    So to accurately answer your first question I I have not noticed anything with the fuel pressure. The only thing I have checked for with that because I was also assuming it was still good since I just replaced it all was that I hear it initialize and that it is sending fuel to the rails.
  11. I can only imagine needing a new pump. I'm assuming this is a bypass system?
  12. Do you have any suggestions for testing the pump again... I just hate the idea of replacing something that has seriously less than 150 miles on it lol
  13. Only thing I can think of doing is running your fuel hose to a bucket. Turn the pump on and see how much fuel comes out. That's how we check the volume a pump puts out compared to manufacturer's specs.