How many of you change the oil in the HPOP at regular oil changes?

Bill Hewitt @Superdutyhelp.com recommends doing it, the dealer says you don't need to, because it changes when you change the crankcase oil.

 

Oh boy! Here we go again.

I don't, some do. Has been covered a lot in previous posts. I think two or three weeks ago even. Should be able to find in a search. Lots of opinions.

 

I bet Bill didn't even change the oil in his own HPOP when he had a 7.3. Great idea if you're a mechanic and dealing with fleet trucks that have a history of poor maintenance. The more oil you get out of the engine the better. Oil in the reservoir won't drain when you pull the oil pan plug, but it sure will start to move when you start the truck.

Of course there's also oil in the rails inside the heads that doesn't come out either. I wonder why he doesn't recommend pulling the end plugs and changing that oil too? Probably has to do with the volume of oil that flows through those parts and the realization that it's just not needed.

I've got 402,000 miles on my engine. I've sucked the oil out of my HPOP exactly once back when Bill first posted that video. I sent it off to a lab for an analysis. I also sent them a sample of my oil from the oil pan during a regular oil change.

The lab found no difference between the oil in my reservoir and the oil that I drained from the pan. Others had analysis done in their trucks also. Bottom line is, there's no difference a lab can find in this "old oil" in the HPOP and the stuff that comes out the drain plug. Bill Hewitt is full of poop.

If you still have doubts, lay a very, very large sheet of plastic on your driveway. Then park the truck on top of it and remove the HPOP reservoir plug on top. Start the engine.

After you're done cleaning up the 10 or so quarts that shot out the hole, come back and tell me you don't think there's enough oil flow through the reservoir to keep the oil in there fresh.

The volume of oil that has to flow through the injectors (and return to the pan) is amazing. If you search on here, you'll find the data so you can do the calculations yourself if you like.

 

Yup, pretty much it... I've never done it either. I've got 330K, but Chris still has me beat. Either way, if our trucks have held up this long, I'd imagine you'd run into other more serious issues LONG before this becomes an issue, if it even could be considered an issue. Bill isn't exactly known for being right. I myself heard him say after he blew up his motor that it was no big deal because he had enough pieces of 7.3's lying around to build another. I'm no machinist, but I do know it's all line-bored and "worn in" so that nothing else fits "right" in place of other pieces. Yeah, it might work awhile, but I can guarantee you it won't last as long as a motor done right.

Something else that might help you picture it is this: like Chris said, the "Low-Pressure Oil Pump" (LPOP) not only supplies the motor with oil throughout, but it also feeds the HPOP reservoir. The "Injection Pressure Regulator" (IPR) regulates the pressure on the injectors. When it wants less pressure, it bleeds excess oil back down into the block and more pressure is the opposite. Also, the injectors bleed oil as they actuate. If you pull the valve covers and watch everything as the motor runs, the injectors are all spitting oil. The amount of oil flowing in the bottom edge of the head is pretty sizable and would fill a bottle in very short order. There's that much oil flowing through... not really getting stale IMHO. One other thing, too, is that there's more oil in the heads than there is in the HPOP reservoir. Kinda defeats the purpose and for as much trouble as it is to "change" the HPOP oil, it's just doesn't really amount to anything.

Hope this helps!

 

Thank you gentlemen for clearing that up....no pun intended. Once again not everything you see on the internet is true, convincing as it may appear.

Sorry for bringing up a topic that has recently been covered.

Art

 

change the hpop screen. Riffraff Diesel: HPOP reservoir gasket w/screen

It might actaully be worth while

 

Why would you need to change it? Remove it if you like and clean it...

But if you find much of anything in there you have bigger issues then the oil in the HPO res...

 

I sucked it out and changed it once...when I replaced my HPOP.

With all the oil coating all the surfaces and the oil pan when you change it, an extra 1/2 gallon isn't going to make much of a difference. Not to mention the risk you take damaging the filter screen or stripping the screw in the access port on top. Not worth it IMO.

My engine has been running fine for 213K without changing it, although it is "young" compared to F350-6 and JonathanN.

 

Brian, you're just broke in!

 

I change mine at every oil change using a vacuum pump - no big deal.
However, I use that chance to fill it with a lubricator/cleaner that will then be directly injected through the injectors thus providing some concentrated 'cleaning action' similar to cleaning a gasoline fuel injection system.

 

I have never attempted to change the HPOP oil as a course of regular maintenance. It's not possible to get all the oil out of the top side so it doesn't make any sense to mess with it. Nothing good will come of it. However, there are a few bad things that can happen so it's just not worth the hassle.

Don't bother with the reservoir screen unless you have the system torn apart already. If your front cover does not have the screen....don't add it.

Don't add anything to your oil. Again, only bad things can happen.

 

How to change the oil in the HPOP reservoir:
Give the throttle a quick blip when you're on the highway.

 

Careful recommending things without a footnote. If someone with an early 99 model tries to instal that gasket it will crack the front cover and result in having to pull the motor.

You do realize that none of that lubricator/cleaner that you dump in the reservoir actually comes out of the injector nozzle, like when you clean a gasoline fuel injection system? It's just being shot out under the valve cover and then mixing with the oil in your crank case. That could actually thin the oil, which would be hard on bearings and such, or cause the oil to foam when it reaches 3,000 psi, which would be hard on your injectors.

 

Seeeee boys, just because we talked about a subject already covered, new do's and don't come to light!

 

Great tip.

It's also worth noting that some late '99 models also have the 'early style' front cover without the screen. So....if you have a 1999 model, you MUST check and see which version of o-ring you have. My truck has the early style, which Bob (dieselorings.com) does not carry so I was forced to re-use it. So far so good...no leaks yet.