Right I know this about the switch, thank you though.

I’m just told the truck was taken to a shop for a crank no start and they said it didn’t have the oil pressure to fire injectors. So I was just asking to see if because the low pressure system read 0 if it could be the same situation I just dealt with in my 6.0. Total failure from lifter failure, needle bearings wrecked the LPOP.

Or if the 7.3 maybe hopefully was settup differently and it could be something less serious.

The 7.3L was not really known for lifter problems OR cam shaft lobe delamination - not like the 6.0L anyway.

It did have a similar style LPOP though, so any hard contamination particle that reached the oil pump could cause it to have problems with flow and pressure.

Huh! So it could possibly be just that the LPOP went bad for a smaller reason and won’t supply pressure to the HPOP and get a no start?

Can you answer me one thing if you know… just incase it’s worst scenario, and somehow the same issue and lifter failure went down and ruined the LPOP, do you have to strip down the entire engine to replace a lifter as I. The 6.0 or is it a normal fix?

Thanks for humoring me

For the 7.3L (and I will emphasize that LPOP issues on the 7.3L are very uncommon):

Here is a thread on a low oil pressure issue with a 7.3L
https://www.powerstrokenation.com/th...failure.83952/

Here are a couple on lifter failure:
https://www.ford-trucks.com/forums/515227-7-3-liter-diesel-cam-lifter-question.html
https://www.powerstroke.org/threads/7-3-broken-lifter.606938/

https://www.dieselworldmag.com/wp-co...-FDTECH-04.jpg The 7.3L LPOP (or lube oil pump, gerotor pump) routes low-pressure engine oil through a check valve and ultimately into the high-pressure oil pump reservoir. Additionally, a short circuit oil gallery is connected to the gerotor pump’s discharge, which provides a quick fill of the high-pressure oil pump reservoir for timely cold starting. It should be noted at the outset that the HPOP can never perform its job without an efficient low-pressure oil pump in the mix.


The above was copied from this web site:
https://www.dieselworldmag.com/diese...-oil-pump-101/

I would imagine you could see the whole range of problems and effects depending on what happened and how long it was run, etc.

Some people don't do routine maintenance, and that can negatively impact oil flow and lubrication. Poor lubrication, or excessive heat build up can cause parts to fail. If parts fail, metal articles can be generated. Injectors can dump diesel into the engine oil and this can prevent the LPOP from producing the needed base oil pressure. Coolant can leak into the engine oil and cause similar problems. Sometimes cam shafts can de-laminate from poor quality workmanship from the factory. This can shed metal and ruin lifters. It isn't a problem that only happens in Ford 6.0L diesels .............

Looking at the picture posted above, metal particles passing through the low pressure oil pump can score the surfaces and gears of the LPOP, and then the LPOP does not generate pressure as it should. The gerotor type pump REQUIRES tight tolerances in order to develop the needed pressure. This is true of the 7.3, and the 6.0L. Remember - Navistar designed BOTH engines.

Who knows what you might find when looking at used diesels.

I really don't know what you are asking for on the 7.3L. It is not prone to LPOP issues BUT.....nothing is perfect, and anything can fail.

For the 6.0L

Since I posted a long list of things that can cause low LPOP (base oil) pressure, then yes - it most certainly COULD be something other than a lifter. A lifter failure typically sheds needle bearings and they make imprints and gouges on the LPOP gears, front cover, and LPOP cover. They are generally obvious when the LPOP is removed. Removing the LPOP is pretty easy.

That said, the FIRST thing you need to do is to VERIFY that the pressure ACTUALLY is low. Do this with a mechanical gauge. There is a test port on the side of the oil cooler that can be used, or an oil filter cap can be bought that has a test port on top.

IMO the MOST COMMON reasons for low base oil pressure in a 6.0L are:

• Aftermarket oil filters not closing the drain valve in the oil filter housing
• On the 03-04 engines, a press fit BB exists on the suction side of the HPOP. When it falls out, you can get low base oil pressure
• On the 05+ engines a BADLY failed STC fitting on the HPOP can result in low base oil pressure

Yes to your question - to replace ALL of the 6.0L lifters the engine has to come out. You would also need to replace the cam - 99% of the time.

Hoping for an update on your issues and resolutions!

Thanks for the thorough answer!

Essentially I'm hunting around for a truck that needs the parts I just put in mine, to get me around before I can afford an engine swap.

Does anyone know if early model 07' parts might be compatible in an 04' model. Both f250 6.0. Specifically looking at HPOP and FICM. I know that the early HPOPS have the ball on the side, and the new one I just put in does not. Is it possible to use a newer one?

All FICM's are interchangeable.

You can not put an 05+ HPOP in an '03 OR ANY '04 engine without pulling the engine, removing the rear cover, and changing out the branch tubes (plus a few other changes)!

This is because ALL '04's came with the round, aluminum case, HPOP's (and all of these have the pressed in BB)! The cast iron HPOP began in '05 - period! NO '04 got the cast iron HPOP from the factory (unless it was some RARE special order item for a member of the Ford family).