7.3 HPOP - Everything You Need to Know About the High Pressure Oil Pump

Jul 22nd 2025

7.3 HPOP - Everything You Need to Know About the High Pressure Oil Pump

What Is a 7.3 HPOP?

The High Pressure Oil Pump (HPOP) is a crucial component on the 7.3L Power Stroke diesel engine. It pressurizes engine oil to fire the fuel injectors via the HEUI (Hydraulically Actuated Electronically Controlled Unit Injector) system. Without it, your injectors can’t function, and the engine won’t run.

Where Is the HPOP Located on the 7.3?

The HPOP sits at the top front of the engine, just behind the fuel filter housing and below the turbo pedestal. It’s gear-driven off the camshaft and sits in a compact valley that can make removal tricky without the right tools.

What Options Do We Have at MSPDieselAutoParts.com?

At MSPDieselAutoParts.com, we offer a full selection of HPOP options for the 7.3 Power Stroke:

  • Remanufactured OEM HPOPs – A cost-effective choice that meets factory specs.

  • HPOP Seal Kits and Fittings – For routine maintenance and leak repair.

All of our HPOPs are tested for flow, pressure, and durability, ensuring long-lasting performance.

What Are the Symptoms of a Failing HPOP?

A failing or weak HPOP can cause a range of issues, including:

  • Hard starting or no start, especially when hot

  • Rough idle or poor performance under load

  • Injector misfires or cylinder contribution codes

  • Low ICP pressure or trouble codes like P1211 or P1212

  • Oil leaks around the HPOP or fittings

These symptoms can progressively worsen over time or appear suddenly.

What Happens When Your High Pressure Oil Pump Goes Out?

If your HPOP fails completely, your truck will likely crank but not start. The injectors won’t receive the high-pressure oil needed to operate, leaving the engine dead in the water. In many cases, you’ll also see diagnostic trouble codes or low readings on the ICP (Injection Control Pressure) sensor.

In fleet or work truck situations, this can mean lost time and serious downtime—something we help customers avoid every day.

How Do You Test a 7.3 HPOP?

There are several ways to diagnose and test the HPOP:

  1. Check ICP Pressure using a scan tool while cranking—anything below 500 PSI usually means a no-start.

  2. Perform an air test of the high-pressure oil system to check for leaks at injectors or fittings.

  3. Use a mechanical gauge to confirm actual pressure at the HPOP outlet.

  4. Inspect for visible leaks or signs of damage around the pump and fittings.

If your HPOP isn’t building pressure fast enough or leaking down quickly, it may be time to replace it.