Below is a good write up on the Powerstroke Injector system (HEUI) w/ the same advice the great resources on this site give regarding filtration and proper fuel and oil care. Nothing real new here if you have been on this forum for a while, but the article just sums it up nicely. I found it at the link below:

http://thepowershop.com/index.php?pr=HEUI

Hydraulically-actuated, Electronically-controlled Unit Injectors (or HEUI injectors for short) will have a tremendous impact for the good, or not so good, for the foreseeable future.

PowerStroke diesel and Caterpillar powered RV vehicles depend on HEUI systems to deliver the fuel and make these engines run. The HEUI design uses a second high-pressure oil pump and delivers a constant flow of very high-pressure motor oil to gallery passages in each cylinder head. (Pressures between 500 and 4000 psi) When the electric solenoid on top of a HEUI injector is actuated, this high pressure oil is directed into a chamber inside the injector and provides the hydraulic pressure to force an intensifier piston to move downward. The intensifier piston in turn pushes fuel out into the cylinder. Fuel is injected into the cylinder at pressures as high as 28,000 pounds per square inch.

The technology described here is really quite amazing. It permits fuel control that is so precise that, combined with the rest of the system, cylinder performance can be monitored and instructions to each injector modified to make a smooth running engine even when other mechanical factors would make other engines run rough.

Priced in the neighborhood of $300 per injector, a set of 8 injectors along with the labor to change them can cost more than we used to pay for a complete engine 15 years ago. These injectors depend totally on clean oil of high quality, clean fuel and fuel with enough lubrication ability to make pumps and nozzles have a long, dependable service life.

NOTE: PowerStroke engines pump filtered oil from the sump to the high-pressure oil pump and then to the injectors.

Because of how hard the oil is "worked", It makes total sense to use the very best synthetic motor oil after break-in. High quality synthetic lubricants can tolerate much higher temperatures without coking or breaking down. The best synthetic oils also keep the engine clean by being able to dissolve deposits and keep them safely in suspension to be filtered out or removed at drain time. It can be a good idea to install a bypass oil filter on these engines. A fine bypass filter slowly filters the oil to remove particles as small as 2 microns. The full flow filter lets particles below 20 to 30 microns stay in the oil. It is the particles between 5 and 30 microns that are responsible for most of the wear on HEUI injectors and engines. Adding bypass oil filtration, in addition to the normal full flow oil filter, will get rid of these small particles, which would otherwise accumulate in the motor oil to become the cause of wear and failures.

Oil is important to HEUI systems but fuel is equally important. The lower section of a HEUI injector is lubricated by fuel. Dirty fuel means injector wear. Changes in our fuel to help the environment have resulted in the fuel we buy being a poor lubricant compared to the fuel of 10 years ago. You need to use a top quality fuel additive in every tank of fuel if you want to get the best life out of your HEUI fuel system components. You also need to stay on top of fuel filter maintenance. Make very sure to use only filters from Racor, Parker, Ford or Navistar, as there are inferior filters available that suffer from torn seals and let dirt into your injection system.

Another fact about HEUI injectors is that they rely on o-rings to keep fuel and oil from mixing or escaping from their proper flow paths and causing performance problems or engine damage. HEUI injectors use 5 o-rings. The 3 external ones have been the subject of a great deal of trouble and do need to be replaced with updated o-rings if they fail. The 2 internal o-rings are not field replaceable. If these fail then the injector or injectors must be replaced. While HEUI systems are inherently reliable if properly maintained they present some diagnostic challenges when injector hydraulics are not working properly. It is often possible to tell which head has a pressure leak but the only way to prove the cause of the leak is a process of elimination. You can change the external o-rings and see if this fixes the symptom. If external o-rings do not fix the symptom then you either have an internal o-ring problem or a leak in the head itself, like a casting crack. You prove which cause is at fault by replacing the injectors in question. If this doesn’t fix the symptom then you have a bad head or heads.

The most common symptoms of injector o-ring trouble are oil getting in the fuel, the fuel filter element turning black, long cranking times before starting, sluggish performance and reduction in power. Increased oil consumption often accompanies oring problems or any fault that lets fuel in the oil.

Any money that was saved by ignoring or neglecting needed maintenance on lower mileage vehicles comes no where near being worth the pain of parting with thousands of dollars for fuel system repairs that could have been avoided.

 

Great link and post!!!

Info that most of know and follow, but amazed at how many like extended oil drains and inferior oil filters. As well, non-OEM fuel filters with the Aqua-bloc technology.

Clean oil and fuel go a long way in these highly tuned, computer controlled motors!! The days of motors that were forgiving and able to be abused are over. If one can spend $40,000 - $50,000 on a SD truck, then they can change their oil, oil filters and fuel filters on or before the normal service intervals (IMO).

 

After reading that, what are your thoughts on a by-pass with extended oil change
(5-7k),for the guys who don't tow heavy. I know I'm not the only one who wants to reduce the operating cost of their truck, without doing it harm.
If we could just eliminate ever other filter change the bypass would pay for itself soon and provide the injestors with cleaner oil the whole time. Ideas?

 

Normal service of the oil and filter is 7,500 miles and severe service is every 5,000 miles.

Many just do it at 5,000 miles as it is an easy number to remember and divides into all future service intervals for the tranny, air and fuel filters.

I use a by-pass oil filter and my insoluables dropped slightly, but just using clean fresh convential or synthetic oil and a Framm, Motorcraft or Racor brand oil filter is key (all are made by Racor - the OEM manufacture).

I use Rotella-Syn as I get the benefits of synthetic oil at a lower cost than many other brands. Even with a by-pass filter, I change my oil and stock filter every 5,000 miles due to shearing (reduced viscosity due to the HUEI injectors). Even with clean/fresh oil, if the viscosity is low... you will do damage to other parts of the motor as well... so no matter what.... most people here (from experience) do NOT do extended oil drains for this reason.

 

This may be a dumb question. Chances are great... Is there a way to add a third oil filter for the line leading to the heads for the injectors? Just a thought, we already have two, what about a possible inline filter?

 

I am sure it has to do with oil pressure or if the filter was clogged for any reason... "lack of oil pressure". I think that regular oil and filter changes has proven to be the best course for longevity of the 7.3L and 6.0L motors.

 

The problem is that the lines reach ~4000 lbs of oil pressure; making any filter explode immediately.

 

I've heard, the oil shears to 30w in 2-3k miles, that leaves 2-3k miles of running 30 weight oil. Ford had to know the oil would shear when they recommended the 7.5K OC, which would be 4-5K on 30w. Ford is not known to be risk takers, so 30w don't really concern me. Dirty oil is another mater.
If the by-pass fliters to 2 microns and the full flow only goes to 20,
I have to ask how much the full flow is actually doing and if it still needs a 5k change. Ford says the filter is good for 7.5k without a by-pass. I'll bet it's good for 10k with the by-pass getting changed ever 3-4k.
Why would clean Rotella-Syn not be good for the full 7.5k miles for LIGHT duty?

 

I would change the full-flow filter sooner and leave the by-pass in for 10,000 miles or so.

Rotella-Syn or any other oil for that matter, can go the 7,500 mile interval, but it is still sheared down to a 30 weight oil. There are many of us that will not leave a 30 weight oil in their motors longer than they need to or within reasonable limits. The manual states not use 30 weight oil when towing or in warm/hot weather. One could assume that we can't stop the shearing effects of the motor on the oil, but we can change out the oil based upon the severe duty cycle rate.

I use synthetic oil for the cold weather operational benefits and for better heat/coking control & protection. I use it year-round and do not like swithcing brands and grades of oil. I change the oil and full-flow filter every 5,000 miles to ensure I have clean oil and have not left the "sheared oil" in longer than what I am comfortable with.

I changed my first by-pass filter at 5,000 miles as well just to see what it looked like and how my Blackstone reports came back. My insoluables levels dropped, but they were very good to begin with. Whether someone uses a by-pass filter or not, it is the redueced viscosity that is of concern for many of us. A by-pass is nice if one can afford it... but do not do extended oil drains in order to justify its cost.

Changing oil and filters (with OEM spec oil filters) is key and using a good quality convential(15W-40) or synthetic(5W-40) oil is just fine. Adding a by-pass filter is just more or better protection but not really needed.

According to people I have spoke too, a by-pass filter works best when the motor is being operated for considerable time. The short, in-town driving creates more soot, carbon and fuel blow-by faster than the by-pass can filter it out... this is why long haul drivers and highway drivers/towers of our Super Duties use it as it can "clean and filter" the oil over an extended time and the oil gets multiple passes through the by-pass filter... plus being heated up and all moisture and traces of fuel get burned off as well.

In the city, the oil gets "by-pass filtered" less times than a highway driven vehicle... either way, a by-pass filter is better than nothing and changing the full-flow filter and oil on time is really key and there is no substitute.

I encourage you not to try and think about it too hard... just change the full-flow filter and oil every 5,000 and the by-pass every 10,000 - 15,000 miles.

 

Great info guys...Thanks a bunch!

 

Excellent post and link regarding the HEUI system injectors! I don't believe in extended oil changes, and after readinging various posts from Beach, I think I've become a believer in oil by-pass systems. I had been mulling over the idea for a little while and now I think is the time to treat my baby to a by-pass system As soon as save up a few more scheckels this will be done!