I purchased this truck a few months ago. 2006 f250 6.0 240k. It was dealership maintained until I bought it. It belonged to a Gc and it was his truck very well taken care of. All the mods except egr delete. It was a Hot no start, it had a broken wire in the IPR pigtail, new motorcraft ipr and pigtail. Ran great for a few months. Always cranked right up. Last month my batteries died. Had it towed home replaced the batteries new motorcrafts. The no start, Only had about 150 - 175 on hpop, had sync. No codes. Air leak was under the Hpop itself I use a fitting in the ipr port. I could feel the air but couldn't actually see or feel the leak. A friend of mine(ford tech) said it was a bad Hpop. I also had an obvious hole in the bellows my uppipe (could also hear it before) so I ordered a new uppipe and a reman Hpop. Had a few leaky injector nipples so new orings on injectors and nipples. New motorcraft standpipes and dummy plugs just because I had them. Oil change, aftermarket oil filter same as I took off. (I've ordered a new motorcraft filter and cap)Now I have zero oil pressure. I have cranked it for days more than enough to see something. I've cranked it from the jumper watching the filter housing, no oil. There was nothing in the oil pressure relief valve, it wasn't stuck. So I'm looking at replacing the Lpop, I don't now what else it could be and I don't know why it gurgles from the reservoir area. Is there anything I've missed, before it was just air no gurgling at all.. Really don't think its a branch tube, I really hope not. My ipr screen was clean didn't find anything that I shouldn't have in the oil. I'm a little frustrated. Any help would be greatly appreciated and welcomed. I guess my main question is would there be oil in the filter housing if the Hpop system won't pressurize? Is the engine dedicating the oil pressure to cranking?

 

Hopefully the re-manufactured HPOP was an OEM one.

The oil filter is BEFORE the high pressure oil sump under the oil cooler. SO - the oil is filtered before it goes anywhere (high pressure system or low pressure system). Unfortunately, the cooler is before the filter though.

Do a test to see how fast you can fill the oil filter housing when cranking. Do it without pushing the housing drain valve closed, then repeat it WITH the filter housing drain valve pushed closed. Post your "fill time" results.

Then, consider installing a manual pressure gauge on the low pressure oil system. There is a test port for that, or they sell oil filter caps that have a port for attaching a gauge (or whatever).

Also consider removing the oil pressure regulator (down by the harmonic balancer).

 

The hpop is a oem reman. There is nothing in the filter housing when cranking either way using the starter cutout on the battery. The oil pressure Regulator was clean and not stuck. I used a magnet and couldn't find anything in it. Like DTRon did in his video.

 

You see absolutely zero oil make it into the housing? I see now that that is how you wrote it up. It is just that you usually see SOME flow - sorry to ask you to repeat that!

I have never personally seen an issue with the oil pickup in the oil pan, but I guess it can come loose (suck in air). Other than that, it is probably the LPOP. I guess pulling the LPOP gears is the next thing to do.

 

Thats kinds what I thought would be the next step. Could the gurgling from under the Hpop while air testing just be from lack of oil in the reservoir?

 

The HPOP itself is supposed to prevent backflow. IMO that is only applicable if there is oil in the HPOP. A completely "empty" HPOP would almost certainly leak some air backwards I would think. But that gurgling would be heard in the reservoir under the oil cooler.

Gurgling under the HPOP would most likely be an IPR leaking (not closing completely), or an STC fitting leaking (IMO anyway), or a leaking HPOP suction o-ring.

 

I kinda thought that was the case, didn't want to be chasing a low pressure problem having a high pressure problem. Air test before and after HPOP replacement while in the same general area definitely sounds different. I'll let you know what I find.