7.3 Powerstroke Engine Problems: The 7 Most Common Problems

The 7.3 Powerstroke is frequently dubbed the “Legendary 7.3.” Apart from being the largest diesel engine ever installed in a high-volume, consumer-grade truck, it is widely regarded as the second most reliable diesel engine ever produced. It is without a doubt the most reliable Powerstroke ever built, trailing only the 5.9L Cummins engine produced from 2003 to 2006.

Between 1994 and 2003, this monstrous 7.3L diesel engine was produced in two variants before being phased out in mid-2003 due to emissions regulations and improved gas mileage.

The 1999 models received a significant power boost, primarily through the addition of a wastegated turbocharger and an intercooler, boosting output from 210hp and 425tq to 275hp and 525tq.

With a reputation for being one of the most over-engineered diesel engines ever, it’s unsurprising that Ford produced nearly 2.5 million 7.3 Powerstrokes before discontinuing production.

7 Most Common 7.3 Powerstroke Engine Problems

  • Camshaft Position Sensor Failure
  • Leaking Fuel Filter Housing
  • Turbocharger Up-Pipe Leaks
  • Bent Push Rods / Valve Springs
  • Exhaust Back-Pressure Valve Failure (EBPV)
  • Under Valve Cover Harness (UVCH)
  • Injection Pressure Regulator (IPR) Failure

While I had to choose seven problems to represent the 7.3, you’ll find that the majority of these issues are extremely simple and inexpensive to resolve. Except for bent push rods (which are uncommon), the majority of these components are sensors and valves that can be easily repaired.

7.3 Powerstroke Reliability

7.3 Powerstroke Engine

When you hear the classic “yeah, my buddy has a diesel with 500k+ miles at his ranch,” it’s a 7.3 Powerstroke, not a 5.9 Cummins. The engine block and internals were vastly over-built and over-engineered for the truck’s power output, resulting in one of the most reliable and trustworthy diesel engines ever produced.

The 7.3 Powerstroke engine has a B50 Life of 350,000 miles, which means that 50% of engines will operate beyond 350k miles without failing. While I did list a number of issues with the 7.3 above, the majority of these issues are minor and inexpensive to fix. Although catastrophic engine failure is almost unheard of, every engine has its weak points. For the 7.3, it’s typically with wiring/electrical components such as sensors and similar items.

Apart from the items mentioned previously, you should anticipate some maintenance as these trucks age and pass the 200k mile mark. It is not uncommon to need to replace the turbocharger (which is surprisingly simple and inexpensive), a water pump, possibly the fuel pump, and other high-stress or pressurized components.

7.3 Front-End Suspension

This is an engine troubleshooting post, not a suspension troubleshooting post. However, I wanted to point out that the front-end of these F250/F350 Super Duty trucks requires slightly more maintenance than the rest of the truck.

Most likely has something to do with the engine’s massive size and weight, which results in some additional wear and tear. Bushings, ball joints, tie rods, and all the other interesting small but critical suspension components do wear out. This includes the steering gearbox, which is discussed in detail here.

1. Camshaft Position Sensor (CPS) Failure

The CPS sensor is located on the bottom half of the engine block, slightly above the crankshaft damper, and it is responsible for controlling both the camshaft position and speed and relaying this information to the Powerstroke’s computer, or PCM.

The engine’s computer uses the sensor data to adjust fueling to ensure that adequate fuel levels are delivered at the appropriate time to control engine timing.

The 7.3’s CPS is widely recognized as the engine’s most common or frequent failure point. The PCM then communicates with the injector driver module via the CPS signal to determine how much fuel to deliver to which cylinder.

When a sensor fails, the PCM is unable to receive a signal and thus cannot instruct the IDM to deliver fuel. As a result, your 7.3 will not start or continue to run.

While it has undergone several design revisions over the years, it continues to be a frequent point of failure. Owners have reported the greatest success with the dark grey and purple CPS sensor that was recently released.

At only $23, we recommend purchasing a second one and storing it in your glovebox in case your CPS fails while you are driving or on a trip. It makes no sense to risk becoming stranded and having to pay for a tow when replacing the sensor is so simple.

7.3 Powerstroke CPS Failure Symptoms

  • Engine cranks but won’t start
  • Rough acceleration and poor idling
  • Check engine light (code P0284 and more)
  • Engine stalls during idle or randomly while driving

2. 7.3 Powerstroke Leaking Fuel Filter Housing

7.3 Powerstroke Leaking Fuel Filter Housing

The fuel filter housing, also known as the fuel bowl, is prone to cracking and leaking fuel. While the pump is constructed of aluminum, the cap is constructed of plastic. The pressure in the fuel system, combined with the heat generated by the engine bay, can cause the cap to wear out or develop cracks, allowing fuel to spew and leak.

The most prone to cracking and leaking are low-quality aftermarket fuel filter caps. While it is less common, we have seen cracks in the aluminum housing itself on occasion.

Apart from a cracked cap, leaking fuel filter housings are frequently caused by leaking o-rings. According to Ford, the chemicals in diesel fuel do not mix well with the coating on the o-rings and oil seals.

Chemicals can cause gaps to form around the o-rings, which fuel can then pass through. The drain valve’s o-rings are known to crack in colder weather, resulting in leaks.

A third possible cause is overtightening the fuel cap, distorting the o-ring, and resulting in a slow drip from the cap.

Leaking Fuel Filter Symptoms

  • Fuel dripping under the vehicle
  • Slow cranking
  • Engine stalls during idle
  • Fuse can blow causing no start

3. Turbocharger Up-Pipe Leaks

Turbo up-pipes are integrated into the exhaust system of the 7.3, connecting the exhaust manifold to the turbocharger. Factory pipes are connected to the manifold and turbo via crush donut gaskets.

The piping expands and contracts as exhaust gases pass through. This expansion and contraction causes the crush gaskets to deteriorate and begin to leak over time.

Symptoms of Leaking 7.3 Up-Pipes

  • Decreased performance
  • Loss of acceleration
  • Increase exhaust gas temps
  • Decreased fuel engine
  • Diesel particulate/soot on the back of the engine, firewall, and tranny

Due to the possibility of OEM up-pipes leaking, the majority of people will upgrade their up-pipes once their OEM set fails. Gaskets on upgraded piping will be stronger, preventing leakage.

Additionally, upgrading this component can help improve the exhaust system’s sound and deep tones. This XDP upgrade kit is an excellent choice for those looking to replace their pipes without adding excessive exhaust noise at an affordable price point.

4. Bent Push Rods / Valve Springs – 7.3 Powerstroke

While these are two distinct issues, bent push rods and failed valve springs frequently coexist. Valve springs are responsible for the smooth operation of the valvetrain and for ensuring that the lifter remains in contact with the camshaft.

The springs do not have a high seat pressure, which could result in valve float at high RPMs. Essentially, when the spring pressure is too low, the valves can “float” or fail to fully seal at high RPMs.

You’re likely to hear engine noises, receive a low compression reading in a cylinder, or cause more serious engine damage. If the spring snaps rather than floating freely, the valve can be thrown into the cylinder, causing damage to the piston, cylinder head, and other internal engine components.

Push rods frequently fail as a result of a weak cylinder, which can be a result of valve spring problems. Additionally, stuck lifters, improper engine timing, and overly tight rocker arms can all contribute to this issue.

Increased horsepower puts additional strain on the push rods and valve springs, which can cause them to bend. If you’re running aggressive power and increased fueling, it’s a good idea to upgrade to performance springs and rods that can handle the increased power.

5. Exhaust Back-Pressure Valve (EBPV) Failure

Exhaust Back-Pressure Valve Failure

The EBPV is a Y-shaped valve mounted on the turbocharger’s outlet. The actuator that controls the back pressure valve is also attached to the turbo. The exhaust back-pressure valve’s purpose is to shorten the time required for the engine to reach normal operating temperature. The system’s third component is an EBPV solenoid or regulator that regulates the flow of oil to the actuator.

When the engine is cold, the actuator closes the valve, creating backpressure as if the engine were operating at full load. Backpressure within the engine results in a buildup of hot exhaust air, which effectively warms the engine up faster.

The actuator is known to force the valve to open and stick-open in cold weather. Additionally, the system frequently leaks oil, necessitating a complete rebuild of the EBPV system. Due to the frequency of oil leaks and actuator failures, as well as the expense of repairing both, deleting the EBPV is a popular option.

Benefits of 7.3 Powerstroke EBPV Delete

  • Increased performance and turbocharger efficiency
  • Lower exhaust gas temps
  • Repairing a failed EBPV requires removal of the turbocharger and is expensive

Negatives of an EBPV Delete

  • Increases engine warm-up time, resulting in increased fuel dilution, particularly in extremely cold climates.
  • Increased emissions, resulting in your failure to pass an emissions test

6. 7.3 Under Valve Cover Harness (UVCH) Failure

7.3 Under Valve Cover Harness Failure

Without getting too technical, the UVCH is a critical component of the fuel injector system on the 7.3 Powerstroke. The injectors require a bit more power than the batteries can provide.

As a result, the engine includes an Injector Driver Module, or IDM. The IDM receives the signal or voltage required to ignite the injectors from the ECM and then outputs a voltage sufficient to ignite the injectors. The UVCH is a voltage-transfer device that connects the IDM to the injectors.

The under valve cover harness, as the name implies, is located beneath the valve cover. Due to the heat generated inside the valve cover and the engine’s constant shaking, the connector wires may melt or rub against the valves and break.

The issue is frequently isolated to a few cylinders, as the UVCH connection on one cylinder may fail while the others remain intact. Each side of the engine has one wire, and fortunately, this is a relatively inexpensive repair.

7.3 Powerstroke UVCH Failure Sypmtoms

  • Poor performance and rough engine running (usually limited to 1-2 cylinders)
  • Engine misfires
  • Usually no check engine light codes

7. (IPR) Injector Pressure Regulator Failure – 7.3 Powerstroke

The IPR, or injector pressure regulator, is mounted on the high pressure oil pump (HPOP) and aids in pressure control. The IPR, in conjunction with the PCM and injection control pressure sensor (ICP), regulates and controls the amount of pressure built up by the HPOP.

This then supplies oil pressure to the fuel injectors, ensuring that the engine receives the precise amount of fuel required to operate. Rather than using a high pressure fuel pump, the 7.3 Powerstroke’s HEUI injection system controls the amount of fuel sprayed into the engine via the HPOP.

As your 7.3 engine ages, it is common for the IPR to fail for a variety of reasons, including the regulator becoming stuck, seals failing, sensors failing, and wires becoming damaged. A failed IPR results in the engine receiving either too much or too little fuel, which can cause a variety of issues.

7.3 Powerstroke Failed IPR Symptoms

  • Rough idling and poor engine function
  • Car stalls at idle
  • Engine cranks but won’t start
  • Surging acceleration, poor shifting, decreased performance

Due to the fact that the IPR operates in tandem with the ICP and HPOP, its failure symptoms are nearly identical. IPR valves can be rebuilt for as little as $20, whereas a brand new IPR valve will cost you close to $200 for the part alone.

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