The 7.3 Powerstroke HPOP is the core of your diesel engine's fuel delivery system.
Well-maintained, you'll drive down the highway, enjoying the rough growl of your diesel engine for hundreds of thousands of miles.
But neglect your 7.3 Powerstroke high pressure oil pump and you're asking for an engine valley full of oil, injectors that won't fire … and a big tow truck bill.
What every 7.3 Powerstroke owner ought to know about the 7.3 high pressure oil pump.
In this 7.3 HPOP Ultimate Buyer's Guide, we’ll look at all the components and systems that interact with the 7.3 HPOP oil delivery system.
The 7.3 Powerstroke HPOP is Ford's application of Caterpillar's hydraulically activated, electronically controlled, unit injector fuel system—HEUI.
Outdated by today's diesel performance standards, the 7.3 high pressure oil pump fuel delivery system was state-of-the-art for its time.
The HEUI fuel system allowed Ford to deliver better 7.3 MPG and increase 7.3 Powerstroke horsepower beyond that of its competition.
Originally, the old body style (OBS) 7.3 Powerstroke engine came with a 15 degree Bosch HPOP - high pressure oil pump. It's a seven piston, gear driven pump mounted to the front cover in front of the engine valley.
The stock 1994 - 1999.5, 15 degree (swashplate) HPOP was replaced by a Bosch 17 degree HPOP swashplate for the 1999.5 - 2003.5 Powerstrokes.
What's a swashplate?
The 15 and 17 swashplate degree refers to the angle of the 7.3 Powerstroke's HPOP swashplate. This angle determines the length of the stroke that the HPOP pistons travel, compressing the oil. The longer the stroke of the swashplate, the more oil volume is displaced by it.
What's the difference between a 15 * and 17 * HPOP, you ask?
The 17 degree will deliver more oil volume and increased pressure. About 300-500psi more at wide open throttle with stock 7.3 injectors.
Here's a Youtube video on how swashplate pumps work:
The one thing I noticed in this video is how important it is to have good grade, fresh oil to keep your 7.3 HPOP healthy. Metal on metal parts, spinning and rubbing on each other for hundreds of thousands of revolutions ... ?
Good lubrication's the key to longevity.
Nowadays, especially on eBay, you can find dozens of remanufactured 7.3 HPOPs with as many different vendors offering "Third Party Manufacturer" and "OEM" remanufactured versions of the original Bosch oil pump.
And there are several fan-favorite 7.3 HPOP upgrades out there. Be aware though, everyone's got an opinion on which one's best.
1994 - 1995
00500 - 216543
1996 - 1997
216544 - 661894
1998 - 1999
661895 - 843989
2000 - 2003
843990 & up
As I mentioned, there are literally dozens of options for obtaining a remanufactured "stock" or upgraded 7.3 HPOP.
Here are my top 5 HPOP options:
7.3 HPOPs in this category are remanufactured to factory specs by a third party manufacturer, NOT an Original Equipment Manufacturer — OEM.
And they may or may not use OEM parts to rebuild the HPOP.
Carefully read the verbiage that product listings use, because "remanufactured TO OEM specifications" does not mean the same thing as "remanufactured BY an OEM" or "with OEM parts."
While the belief that OEM parts are superior to aftermarket is debatable, 7.3 HPOPs in the "Third party remanufactured" category retail well below "OEM parts remanufactured to OEM specs by an OEM" 7.3 HPOPs.
What this remanufactured 7.3 HPOP does
This 7.3 high pressure oil pump is a direct bolt-on replacement for the 1994 - 2003.5 stock 7.3 HPOP. (Must contact seller to determine fitment and model year HPOP version before purchase)
As I mentioned, this is a stock HPOP replacement. Use it to remove and replace a weak or failed factory 7.3 high pressure oil pump. It's meant to be used with stock injectors.
Who should buy a third party remanufactured HPOP
The truth is most of the HPOP remanufacture companies out there do a good job.
If you look at the ratio of positive to negative feedback and reviews, a very few customers who've had a bad experience can make it seem like every part that ships is a pile of junk.
As unfortunate as getting a faulty part is for an unlucky few — believe me, I've been on that list a couple times — the reality is that one bad egg doesn't mean the entire production run's bad.
Look for a seller that stands behind their product and handles returns well.
Get this 7.3 HPOP if:
In any of those cases, a budget high pressure oil pump is for you.
Bottom line is that this HPOP fits the DIY/shade tree mechanic on a budget category. Especially if you've got more time than money.
What I like about this 7.3 HPOP
No core charge for 30 days. And they've sold over 100 of these pumps with no complaints.
Did I mention that this HPOP is inexpensive?
What to look out for with this HPOP
I read the seller's past year's negative reviews for all their listed products. Most of them were about failures out of the box with injectors and other products than this HPOP.
The good news is that they address every customer complaint in the comments/feedback section.
Just be aware — you'll save money, but any remanufactured part has a certain percentage of them that will fail. And no matter how small "1%" failure rates may be, none of us likes to be in that one percent.
If you live and breath "OEM", "new", or "factory warranty," you need to spend the money for a new or OEM 7.3 high pressure oil pump.
If your stock injectors are starving for fuel due to a weak or old HPO, this pump will give them a boost. I wouldn't use it with upgraded injectors.
This is a good solid budget option from a good seller who stands by their products.
No list of top 7.3 HPOP upgrades would be complete without including Sinister Diesel's remanufactured high pressure oil pump for your 7.3 Powerstroke.
In business for years and building a reputation for rock-solid pump rebuilds, Sinister Diesel is based out of Roseville, CA.
Who should buy a Sinister HPOP
A true OEM spec upgrade for someone who wants a nice new, well-performing 7.3 high pressure oil pump rebuilt with OEM or OEM spec aftermarket components.
With Sinister's remanufactured 7.3 HPOP you'll get a performance boost across the board and the peace of mind knowing that your pump is rebuilt by a company that's done tons of rebuilds.
What I like about the Sinister HPOP
Sinister's 7.3 HPOP is an upgrade that'll give you increased performance for stock or mildly upgraded injectors.
What the Adrenaline HPOP 7.3 Powerstroke Upgrade does
The Adrenaline HPOP is a great choice for use with any injectors you have — from stock to big 275cc.
It's a true bolt-on performance and fuel efficiency upgrade. Larger injectors will get the most benefit from an Adrenaline HPOP upgrade, but stock sticks will get a noticeable boost in power and 7.3 Powerstroke MPG too.
Who should buy an Adrenaline HPOP for their 7.3
Looking to get a big boost out of your stock injectors? Or if you want to future-proof your HPOP for the day you save up to buy bigger and badder injectors, this is the last HPOP you'll ever need to install in your truck.
This Adrenaline HPOP fits 1996 - 2003 7.3 Powerstroke diesel engines.
P1211 codes? Weak or leaking HPOP? Running a performance tuner that you want to get the most out of? The Adrenaline HPOP will handle all that and more.
What I like about the Adrenaline HPOP 7.3 Upgrade
This is the pump I'll be bolting onto my stock 2002 F250 7.3 Powerstroke. I can't afford a big injector upgrade. But in the future, I'd like to be able to upgrade to bigger injectors without the expense of getting another pump that will be able to actuate them.
Spend a little more on this Adrenaline HPOP now, to save replacing your HPOP twice.
I think we can agree that for most of us, the technical details of how a 7.3 Powerstroke HPOP works are less important than making sure that it does work.
Because whether you just want to get more oil volume to your Powerstroke's fuel-starved stock injectors or be able to deliver enough pressure to fully utilize your expensive new high performance 7.3 injectors....
Well, you need to know what an HPOP does.
When I was reviving my 2002 F250, the first thing I Googled when I found out I had an HPOP leak was, "What does the HPOP do on a 7.3?"
Because I had no idea.
After researching my HPOP for over 23 hours for this post and just because I'm techno-crazy that way, I boiled it down for you:
So, if your 7.3 HPOP is leaking or malfunctioning in some way, the injectors won't get enough pressure to fully actuate and if your HPOP's really bad, your truck may not even start.
The 7.3 HPOP is located right in the center of the engine compartment at the front of the engine valley.
But it's positioned behind and under two other major components in your 7.3's fuel delivery system...
The 7.3 HPOP reservoir is the rectangular grey part that sits in front of the fuel bowl.
The actual high pressure oil pump is located beneath that fuel bowl housing.
Here's a quick video of the 7.3 HPOP and HPOP reservoir locations:
NOTE: This video was filmed on my 2002 Ford F250 7.3 Powerstroke. I've replaced the stock 1/4" fuel lines with 3/8" braided lines and black AN fittings. So those fuel lines coming off the left of the fuel bowl won't look like your stock ones.
But this location diagram should make it a bit clearer:
This is a diagram of the 7.3 HPOP and HPOP reservoir locations.
As you can see the actual HPOP unit itself sits between the two heads, behind the reservoir.
Let's get back to how the 7.3 high pressure oil pump delivers all that oil...
The 7.3 HPOP lines connect the high pressure oil pump to the oil rail galleries on the cylinder heads.
Oil flows from the HPOP through your 7.3 high pressure oil lines to the oil rails.
The 7.3 HPOP oil lines are designed to withstand pressures up to 3000 psi.
Those high pressure oil lines attach to the HPOP and the oil rails on the cylinder heads by way of 4 STC "snap to connect" fittings.
There are two quick connect high pressure oil fittings on the HPOP and two quick connect/disconnect fittings on the cylinder heads.
These fittings are one of the top, if not the primary, 7.3 HPOP leak locations.
The 7.3 HPOP fittings are sealed by four O-rings. Two O-rings on each fitting.
There's one HPOP fitting O-ring on the outside at the base of the HPOP fitting above the threads. This O-ring seals the fitting to the HPOP.
The O-ring on the collar of the HPOP fitting seals it to the high pressure oil line.
The fittings at the cylinder heads have an O-ring on the inside of the collar. It seals the other end of the 7.3 high pressure oil line to the disconnect fitting at the cylinder head.
Many Powerstroke DIYers simply replace the entire fitting instead of fiddling with replacing HPOP O-rings. But buying the O-rings gives you control over which ones are used.
Many swear by using Viton O-rings to replace your HPOP fitting O-rings. Claims are that the stock O-rings that come with some fittings wear out and leak too quickly.
For more detailed instructions on removing the 7.3 HPOP lines, including PART NUMBERS and Torque Specs, read these 7.3 HPOP removal and replacement procedures.
We'll get back to the 7.3 HPOP O-rings in a minute...
The HPOP stores oil in the HPOP reservoir in order to continuously supply the high pressure oil pump with oil.
When the engine's turned off, a check valve in the high pressure oil pump keeps about a quart of oil in the reservoir. It does this in order to be ready to provide oil volume/pressure for the next start.
Otherwise, without oil available to the HPOP, you'd have to continuously crank the starter to fill the reservoir back up.
This would tax your batteries and your starter before eventually making enough oil "pressure" available to fire the injectors.
But, here's the kicker:
The 7.3 HPOP delivers volume not pressure...
Despite its name, the high "pressure" oil pump delivers oil in volume to the oil rails on the cylinder heads.
Creating the oil pressure that actuates the injectors is the job of the 7.3's IPR—Injection Pressure Regulator.
The IPR creates pressure in ranges from about 500 psi at idle to 3,000psi under heavy throttle. (Tuck Trend has a detailed explanation of how high pressure oil injection systems work.)
But if you don't like reading technical details, here's the simple version?
The HPOP delivers a volume of oil for the IPR to pressurize via commands from the ICP sensor. This starts an injector firing sequence by which the 7.3 injectors ultimately spray fuel into the combustion chambers.
As I mentioned, delivering enough pressure to fire the injectors and controlling general engine performance is the function of...
The 7.3 IPR (Injection Pressure Regulator) manages the HPOP's oil outlet pressure.
Not enough pressure and the injectors won't fire. i.e The engine won't start.
The HPOP and the IPR work together to actually "create" the oil pressure. The HPOP provides the volume and the 7.3 injection pressure regulator actually physically produces the psi — pressure.
The ICP sensor sends the current pressure reading to the PCM which in turn signals the 7.3 IPR to add or reduce pressure.
Ideally, the four of them provide enough oil pressure to the injectors so that when you stomp on the accelerator, your injectors fire and away you go...
The HPOP Unit itself doesn't usually fail. However, after a couple hundred thousand miles your 7.3's HPOP may lose efficiency. i.e. your HPOP won't be able to produce the psi it did when it was new.
A weak HPOP will still run your truck. It'll just be low on power.
As symptoms go, the 7.3 Powerstroke can exhibit a host of drivability issues that can be attributed to many different parts.
What points to the HPOP could just as easily be the ICP, IPR, bad batteries, weak starter, dirty oil...
The point is, start at the easiest things to check first.
Are your batteries good? Is your starter cranking hard enough? Do you have an oil leak? Have you changed your oil frequently enough?
Once you're done with the obvious, move to deeper inspection of your 7.3 HPOP.
Accelerating or pulling a heavy load you get a P1211 code: "Injection control pressure higher or lower than expected."
This could be caused by several things. A leaking, bad or stuck IPR or a performance tune that's delivering excessive pressure to the oil rails, or a bad or leaking ICP — injection control pressure sensor.
As always, check for leaks first. Then unplug your ICP pigtail and inspect it for oil. If there's any oil in the ICP or pigtail, replace the ICP and the pigtail.
You have low injection control pressure (ICP) less than 2600 - 2800psi. An aging or failing HPOP will not be able to maintain its factory max operating pressure of 3000psi.
Check for an HPOP leak in one of the 7 HPOP leak locations listed below. If there are no leaks, and your HPOP is delivering below 2600-2800psi, you may need an HPOP replacement.
The 7.3 HPOP itself shouldn't be effected by heat per se. But when oil is cold it's thicker and thus less likely to escape through a leak.
Hot oil is thin and more likely to leak.
Check for an HPOP Oil leak and repair as needed. (Probably O-ring replacement kit). If a leak's not the issue, check the IPR duty cycle and/or the ICP sensor connection for oil buildup.
You may have introduced air into the system.
In any 7.3 HPOP repair, the HPOP reservoir level needs to be checked/refilled manually and then the air released out of the system.
The 7.3 engine is tilted back in your engine compartment, so air bubbles will naturally flow up and to the front of the oil system.
Since the high pressure oil system is a closed system, you may have to release any air bubbles in the oil rails by removing the ICP after driving it.
Many things can cause a loss of fuel efficiency. But if you notice a sudden drop in fuel economy or your truck begins to idle and accelerate poorly, your HPOP may be the culprit.
Lower oil pressure to your 7. 3 injectors means less efficiency in delivering and burning fuel. Additionally, chugging, missing, or rough running may indicate that your HPOP has a leak or is getting old and not providing enough pressure to fire the injectors properly.
Check for leaks and ICP pressure.
If your 7.3 HPOP isn't strong enough, or if you're running a performance tune that's maxing out its capabilities, your engine can run rough after a hard throttle.
Some report that changing the HPOP reservoir oil helps, but the bottom line may be a failing or weak/old HPOP.
Look for leaks and then consider an HPOP replacement or upgrade to handle any performance tunes or upgraded injectors you may be running.
High EGT and low boost pressure may allude to a weak HPOP, but there's nothing like smoke coming out your tailpipe to tell you that fuel isn't being burned up in combustion.
The HPOP pressure actuates the injectors. If they aren't operating at peak performance then excess fuel is leaving through the tailpipe as black or white smoke.
Remember this: Black smoke — fuel not being burned up completely. White smoke — worn out injector. Blue smoke — oil in the combustion chamber.
None of them are good.
And finally, if things get bad enough, your HPOP can cause a no start condition. The ICP expects to see a minimum of 500psi from the 7.3 IPR and HPOP in order to start your engine.
A cold starting pressure below 500psi and your truck will crank but not start. Many things can cause a no start, but a worn out HPOP will cause a no start.
We've talked a lot about leaks...
Despite the gradual reduction in psi that a couple of decades old HPOP may incur, by far the most common problem you'll experience with your high pressure oil pump is an HPOP leak.
There are several places that your 7.3 HPOP might experience a leak.
The most likely reason for a leak in your high pressure oil pump is a failure of one of its many O-rings.
As we mentioned above, the 7.3 HPOP O-rings seal up the high pressure oil pump's various fittings, plugs, and the IPR.
The O-rings prevent all of that pressurized oil from escaping and filling up your engine valley or leaking down the front of your engine cover.
Oil buildup in your engine valley — between the two cylinder heads — is one of the first signs that you may have an HPOP leak.
First check to see if you have an oil leak in your valley
A high pressure oil pump leak won't take much to push more oil out. Locate where it's coming from by looking for fresh oil at one of the leak locations in the diagram above.
But oil in your valley isn't the only place to check. A leak in the non-serviceable plug may drip oil right down the front of your engine cover.
Thoroughly inspect any suspected oil leak back to its origin.
Next up, an often overlooked 7.3 Powerstroke HPOP symptom...
There's a check valve/ball inside the 7.3 HPOP reservoir.
It's job is to prevent the reservoir oil from draining back down into the engine oil pan.
If your HPOP Reservoir level is draining slowly (low) or won't stay full when you fill it (empty), there may be a problem with your reservoir's check ball valve.
Remember those HPOP o-rings?
Ford truck forums are packed with tales of leaking HPOP fittings. Usually the o-rings. But the rear drain plug, non-serviceable plug, or the rear plate o-ring can slo fail and leak.
See HPOP Leak Locations Diagram below for details...
The two HPOP oil line outlet/"discharge" fittings have 2 O-rings each.
The HPOP rear drain plug O-ring.
The HPOP "Non-serviceable" Plug O-ring
The O-ring that seals the IPR to the HPOP
The rear plate O-ring, sealing the pump
To fully understand all the HPOP oil leak locations and how to fix them, read this article on how to fix a 7.3 HPOP oil leak.
If you have a diagnostic scan tool, here's a quick way to check if your HPOP is good:
In general, if your truck's HPOP can maintain 2800psi it's in pretty good shape.
Most older Powerstrokes can only maintain around 2200-2600psi of ICP/HPOP pressure.
Down below that, your HPOP won't be able to deliver full performance to your injectors. And you won't get much out of new high performance injectors, either.
That's when it's time to look for a new HPOP.
There are several 7.3 high pressure oil pump rebuild kits out on the market.
In them, you'll get everything from just the HPOP fittings and drain plug O-rings to an entire HPOP rebuild kit.
The kits will have O-rings for everything, including the IPR, as well as a new serviceable plug and check ball to replace the non-serviceable plug.
And don't forget the Loctite 680 to secure the fittings back to the HPOP.
Keep in mind, for any of these options you're going to have to remove the fuel bowl and remove the 7.3 HPOP.
The original 7.3 Powerstroke high pressure oil pumps were made by Bosch.
Remanufactured versions of that 7.3 HPOP are available everywhere online.
Most manufacturers will require that you return your old 7.3 HPOP. They will likely charge you a core charge until you ship them your old HPOP.
Look for verbiage like this: "Remanufactured to OEM Specifications".
The decent ones come with a year warranty and include a 7.3 HPOP mounting gasket.
Here's where things get interesting...
New high performance, high flow HPOPs aren't for everyone. They won't give much of a boost to worn out stock injectors. In fact, all that increased pressure could do more harm than good if your truck has weak or failing injector o-rings.
So make sure you know what injectors you have and how they're performing before upgrading to a more powerful HPOP.
That being said, a newly upgraded high flow HPOP combined with new 7.3 injectors that can take advantage of the increased oil volume and pressure?
Well, that will make you wonder how you ever lived without it.
Especially when you're towing.
I hate to say it, but there is no "best" HPOP.
Which high pressure oil pump is right for you is largely dependent on what you want to do with your truck and your budget.
Is your truck a towing workhorse? A daily driver? Your fun toy to go four-by "mudding" with? Or are you a gearhead trying to get that last ounce of horsepower out of your heavily modded 7.3 Powerstroke?
Take a look at the BUYING OPTIONS at the top of this article to get recommendations based on your application.
But regardless of how you choose to upgrade your 7.3 HPOP, you'll need to know how to do this:
Knowing how to remove the 7.3 Powerstroke HPOP is required learning to fix some high pressure oil pump leaks and a must if you want to upgrade your HPOP.
There's much more detail in the 7.3 HPOP Removal and Replacement article, but here are the quick and dirty steps to 7.3 HPOP removal
Now you should be able to remove the HPOP from the engine compartment. Careful — it's gonna be messy.
Get the full 7.3 HPOP Removal and Replacement details.
And finally, let's discuss the most controversial, taboo subject on ALL the Ford Powerstroke Forums:
There are two types of 7.3 Powerstroke owners: the ones who change their HPOP oil and the ones who laugh at us... So no, I'm not going to get into whether or not you should change the oil in your HPOP.
Simply put, some people say replacing the HPOP oil should be part of every 7.3 oil change. Then there are people who believe that a 7.3 HPOP oil change is myth and the equivalent of snake oil.
Do what's right for you. But every time I've changed my 7.3's HPOP oil it's been sludgy and nasty looking. And after putting 1/2 quart of 15w-40 and a 1/2 quart of Archoil (whoops, more snake oil. heh-heh-heh) back in my HPOP reservoir...
At the very least, it makes me feel better. And I swear my 7.3 injectors purr like a kitten afterward. Reason enough in my book.
We explained earlier how to check the 7.3 powerstroke HPOP oil level. I'm going to write a detailed post on how to change your 7.3 oil, start to finish.
For now, check out this 7.3 Powerstroke HPOP oil change video by one of my favorite 7.3 gurus over at powerstrokehelp.com.
7.3 Powerstroke OIL CHANGE and CAPACITY Secrets
7.3 Powerstroke INJECTORS – Ultimate Buyer’s Guide