My 2010 XLT with 5.4l had severe problems after which I installed new cam phasers, VCT solenoids, sensors, timing chain and guides, as well as a Melling 360 oil pump. As the engine has in excess of 150,000 miles, I installed a mechanical oil pressure gauge to monitor performance. It runs smooth as silk now, with oil pressure at 40+ at 1000 rpm and 60+ at cruising speed. BUT, when stopped at a traffic light, rpm drop to about 500 rpm and oil pressure fades to25 to 18. At 20 lbs, the engine begins rocking and rattling, and wants to stall. As the pressure is good above idle, I do not think rolling the bearings would help. My $100. solution is to install an electric high pressure external oil pump that would be activated when the gas pedal is at idle and shut off when the pedal is activated. I am considering using a Walbro 255 LPH inline fuel pump that delivers 130 psi, rather than a scavenging pump, hoping that the Walbro can handle the thin hot oil. It would scavenge the oil from the drain plug. What I do not know is where can i tap into the oil gallery to supplement the Melling? Any help from professional motor rebuilders would be appreciated, as well as any other comments and suggestions. It may be the solution a lot of Ford owners have been looking for.

 

You could find the oil filter adapter that goes on the older 4.6/5.4 that had the oil filter behind the front bumper and run a remote oil filter thus tapping into the line going back into the motor.
Now not to put a fly into the ointment, will the oil get back down to the pan fast enough or are you in the long run going to find out your motor is starving for oil because you do not have a big enough reserve? What you are planning to do is run a dry sump system without a separate sump.

 

What happens at 600-800 rpm under those same conditions?

If the oil pressure is good with a couple hundred more rpm, I'd look into a tuner that can raise the idle rpm.

What weight if oil are you using? I'd try a bump to the next grade before I did anything else. 5w30 or even 5w40 would be fine. I've been using 5w30 for a long time in mine because it is noticeably quieter than the spec. 5w20.

I think the oil filter adapter might be a promising idea if the pump could handle flow when it is powered off.

Have you done an oil analysis? Something is wrong with the engine, an analysis might give you a clue as to what. I wonder if the top end got starved for oil and that's why you are losing pressure at idle. Aluminum might be your harbinger for a problem up top.

 

Thanks for your helpful comments guys. I started thinking about mechanical ways to raise the rpm at idle and I ended up taking off the throttle body for a good look. What appears to be a 10 mm plug is actually the butterfly stop. Screwing it in about 3/4 turn has raised my idle rpm to about 600 with oil pressure at 25 psi. It still rattles a bit at hot idle, but much better than before. I may try another adjustment and see what happens.

 

It sounds like you've found an easy work around. I'd take the idle up only as far as it takes to get about 25psi hot idle and ride it out until something else changes.

I Will warn you though, as your in gear idle gets up around 850 rpm you will find that holding it back with the brakes takes much more effort. Keep the idle as low as you can just to maintain the oil pressure and driveability.