Ford 2.5L Duratec I4 Engine Problems: Everything Need To Know

A naturally aspirated inline-four cylinder engine, Ford’s 2.5L Duratec engine, or the Duratec 25, was available from 2009 to 2019. The Mazda L5 engine served as the basis for the I4 Duratec’s development in collaboration with Mazda. The 2.5 Duratec had a power range of 156-175hp and torque of 136-172lb-ft. Ford’s new EcoBoost engine family replaced the 2.5 Duratec in 2019 and eventually phased it out.

There was a 2.5-liter Duratec in every Fusion and Escape. More power was available as an option with the 1.6 and 2.0 EcoBoost engines.

The 2.5L Duratec V6 engine was developed by Ford and Mazda in the early 1990s. There are two distinct Duratec 25 engines, one for I4s and one for V6s, despite the fact that they share the same name but are completely different engines. The Duratec V6 was manufactured between 1994 and 2002, and it was primarily used in the Ford Mondeo as an international engine.

Specifically for the I4 Duratec 25, this list of troubleshooting steps is geared toward you.

The 2.5 Duratec has a maximum output of 175 horsepower, which makes it easy to overlook. Even though it’s not a car enthusiast’s dream engine, it’s a great option for people who just want to get from point A to point B.

2.5 Duratec I4 Vehicle Applications

  • 2009-2019 Ford Escape
  • 2010-2019 Ford Fusion
  • 2010-2013 Ford Fusion Hybrid
  • 2014-2018 Ford Transit Connect
  • 2011 Lincoln MKZ Hybrid
  • 2010-2013 Mercury Milan
  • 2010-2011 Mercury Milan Hybrid

Ford 2.5 Duratec I4 Common Problems

Ford 2.5 Duratec I4 Common Problems

It was nearly impossible for me to identify any common issues with these engines. The Duratec I4 has been dubbed “over-engineered” by some. While I accept your point of view, a broken piston or problems with the engine’s internals, block, etc. are extremely unlikely with a 2.5L engine making only 175hp.

This is fantastic news in terms of dependability, and the fact that I haven’t discovered any major issues with this engine proves just how long it will last.

  1. Excessive Coolant Consumption
  2. Transmission Hard Shifting
  3. Power Steering Failure

1. 2.5 Duratec Excess Coolant Consumption

Duratec I4 owners complain most about the engine’s tendency to sip engine coolant. In contrast to most cars, which require a coolant top-off no more than once every few years, most owners report having to refill on coolant once or twice per year.

Although the Fusion and Escape both use a lot of coolant, no one knows for sure why. However, no obvious coolant leak has ever been found to be the cause, leading some to believe that engine block porosity is to blame.

Despite the fact that we are unaware of a solution to this problem, it is critical that you are aware of it. The engine can overheat if you have insufficient coolant in the radiator. Whenever an engine overheats, it poses a serious risk of damaging the engine’s block, heads, and other internal components. Keep a spare bottle of coolant in your trunk just in case your car’s coolant warning light comes on in the middle of a long drive and you run out.

Aside from sudden, unexplained coolant loss, there are numerous other reasons for coolant leaks. If your radiator is cracked, your cooling system is losing coolant because of leaking water pumps and hoses, as well as a blown head gasket or cracked head cylinders.

Symptoms of Coolant Loss

  • Low coolant warning light
  • Engine overheating
  • Possible coolant leaks

Potential Causes of Coolant Loss / Leaks

  • Cracked/leaking radiator
  • Bad radiator cap
  • Blown water pump
  • Leaking hoses
  • Blown head gasket
  • Expansion tank failure

2. Transmission Shifting Problems – Duratec 25 I4 

Transmission Shifting Problems

These vehicles all have a conventional 6-speed automatic transmission. Unfortunately, the transmissions have leakage problems, resulting in low levels of transmission fluid and a host of problems, including shift difficulty, shifting irregularly, slippage, and more. Around the 70,000-mile mark, problems will begin to appear in Fusions and Escapes manufactured in 2012-2014.

While 2012-2014 cars are most likely to have these issues, we’ve heard of problems with vehicles from other years as well. A leaking shaft seal on the transmission’s left side is usually to blame for the problem.

On the front of the transfer case, there is an output shaft seal that keeps the output shaft sealed to the case. Seals, like all mechanical components, degrade over time, allowing transmission fluid to leak out of the output shaft.

The powertrain and transmission control modules are another common source of transmission issues in these vehicles. Occasionally, software calibration will become out of sync and will require an upgrade to fix the problem. When the TCM/PCM is malfunctioning, you may notice jerky or sluggish shifting between the first and second and fourth and fifth gears.

Tranny fluid leaking from the transfer case is the most obvious sign. Many 2.5 Duratec owners, on the other hand, are completely unaware of the leaks until it’s too late. Once the transmission has lost a significant amount of fluid, problems such as rough shifting and gear slippage become common.

First, make sure there are no leaks in your transmission or transfer case. If the fluid is clean and there are no leaks, the problem is most likely with the PCM/TCM. To learn more about the potential ramifications of a TCM or PCM upgrade, continue reading.

Leaking Transmission Fluid Symptoms

  • Fluid leaking from transfer case
  • Hard shifting
  • Gear slippage
  • Delayed shifts

Replacement / Prevention Options

Powertrain control module and transmission control module software can be reprogrammed or upgraded by Ford to fix these problems. It is possible that the software update is merely a band-aid solution, leading to more serious fluid leaks, and ultimately clutch and transmission failure.

The software update for the transmission increases transmission pressure to avoid leakage.

However, the increased pressure damages the output shaft seal over time because it causes more wear and tear. While this is an option in a small number of cars, make sure you don’t have any fluid leaks before you try it. Instead of reprogramming the control modules, replace the output shaft seal if you have fluid leaking.

Preventing problems and extending the life of your transmission is as simple as making sure the transmission is always full of trans fluid.

3. Power Steering Failure – Fusion & Escape

Ford Fusion and Escape drivers may face a potentially dangerous issue, even if the issue isn’t engine-related. EPAS (Electronic Power Assisting Steering) units were installed in place of the hydraulic power steering units. The new system reduced the complexity of power steering by eliminating the need for hydraulic pumps, pulleys, and fluids. However, the fact that computers now control the entire system complicated matters.

As part of the new EPAS system, the steering wheel position sensor is controlled by an ECU as well as a motor. The problem with the 2.5 Duratec’s EPAS system is that the torque sensor frequently fails.

When you turn your steering wheel, the torque sensor measures how hard and how far you’ve pushed the pedal. This sensor is the most common source of failure, and it usually goes bad without warning.

Whenever a sensor malfunctions, it ceases to transmit a signal to the ECU, which in turn turns off the power steering unit. You’ll eventually lose steering assistance and struggle to turn the wheel, particularly at low speeds.

Torque Sensor Replacement

Because of this, replacing the torque sensor will not suffice. Because the torque sensor is integrated into the steering column, it can only be removed by removing the entire column. Fortunately, this problem was brought to the attention of the public for the vast majority of Duratec 2.5 models.

2.5 Duratec I4 Reliability

Finding common issues with the Duratec 25 was difficult, as previously mentioned. These engines may be underpowered, but they’re incredibly dependable. As long as you don’t abuse the engine’s 175hp/2.5L capacity, it should last for many years.

This engine is virtually trouble-free on its own, according to our research. There have been transmission and power steering issues with some of the Fusion and Escape models equipped with the engine, but nothing major. They have a reputation for guzzling coolant, so be sure to top them off as often as necessary.

It’s hard to say how reliable these are with more power because there aren’t many performance modifications for the Ford 2.5. However, it’s safe to say that these engines are incredibly dependable when left in stock form and only used to get from point A to point B.

Yes, they have a high level of dependability, but as they get older, they will require more maintenance. There will be a number of basic repairs that need to be made as you approach the 150k-mile mark like water pumps, spark plugs, and ignition coils, carburetors, fuel injectors, seals and gasket, and suspension components.

A well-cared-for 2.5 Duratec can go 250,000+ miles before needing to be replaced.

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