Hello everyone,
I am new to the forum and was hoping someone could help me with an issue. While driving today, 2006 Ford F-250 5.4 L V8 138,000 miles , I experienced a problem. Started with the truck acting as if it was running rough, possibly missing. This was approx. 10 Minutes after starting. Checked the dash, no warning indicators and all gauges were normal. Approx. 4 more miles, the oil pressure alarm signals and I see the oil gauge has dropped to zero. I pull over, turn off and check the oil. Oil is clean and at a normal level. I restart the truck and the oil pressure goes back to normal. Rev the truck up while sitting there and after a few seconds i hear a knocking noise in the engine and oil pressure drops again. Call the tow truck, driver used to be a mechanic . He asks me to start it again and the same thing happens. If you start it and let it idle oil pressure seems to go up to normal with no engine noise. Finaly get to the mechanic and he calls me later saying the oil pump and screen may need to be replaced or the engine may need to be replaced. Anyone have any other ideas. I am stumped. Thanks in advance for any responses.

 

I think I would pull the pan and have a look.


Does not sound like a pressure regulator issue since the guage does read good and motor runs good.


then bad and pressure goes bad.


Pull the pan and go from there.

 

I would change the oil pump but what concerns me is the knocking noise which could be just from the lack of oil but if not than there may be a bigger problem. If it was me a whole tear down for sure if I was going after the oil pump any way to inspect everything. It may be cheaper in the long run than replacing the pump than starting it up and doing more damage.

 

Thanks for the replies. Turns out my mechanic flushed the oil twice and let it run and we have driven it over 50 miles since with no issues. It appears there was something blocking the flow of oil. Only question is, was any damage done during the lack of oil. Hoping that since it did not run hardly at all during the issue we will be ok. At least for now. Oil pressure has remained steady with no knocks and pings. Keeping fingers crossed while keeping eyes open for a trade in.
Thanks again