Ford 3.5 EcoBoost Problems: Reliability, Common Issues & Years to Avoid

Reviewed by Eric Shepherd, ASE-Certified Technician (and Gemba’s Accidental Social Media Star!)

Did you know that Ford’s 3.5-liter EcoBoost engine that powers the F-150 is the same engine powering the Blue Oval’s supercar, the Ford GT? The 3.5 EcoBoost can be found in everything from a Ford Transit van to the Taurus, Explorer, Expedition and even a few Lincoln models. Yes, the 3.5 EcoBoost has spent years doing the kind of work that truck and SUV owners ask of it: commuting, towing, road-tripping, and surviving Arizona afternoons in the summer. And it’s even set a few records on the racetrack.

The engine has also been around long enough to develop a bit of a complicated reputation. If you search for 3.5 EcoBoost problems, you will find a variety of issues that range from startup-rattle videos to claims that you should avoid it altogether. In reality, there isn’t a universal list of problems that plagues every 3.5-liter EcoBoost ever created. Ford has revised the engine over its production life and documented concerns can vary by generation, application, model year and even the build date.

Those kinds of details matter if you already own an EcoBoost-powered Ford or you’re at a Phoenix dealership considering buying a used F-150 with 130,000 miles and you’re wondering if the engine still has some life left in it.

Is the Ford 3.5 EcoBoost a Reliable Engine?

In general, the Ford 3.5-liter EcoBoost is a reliable engine. However, the reliability largely depends on which version of it you have and how it has been maintained. The twin-turbo V6 has been revised substantially over the years and that means if there is a documented issue with early EcoBoost engines, it shouldn’t be assumed it’s still an issue on a more modern vehicle equipped with it.

The maintenance history is the most important indicator of reliability. You will want to look at the following:

• Oil-change history
• Cooling-system condition
• Spark plug maintenance
• Towing habits
• Previous repairs
• Modifications
• Mileage

A well-cared-for higher-mileage truck has the potential to be more reliable than a lower-mileage example with a questionable service history. At the end of the day, don’t assume all 3.5-liter EcoBoosts were created the same. The generation, vehicle it is in, condition and maintenance history all tell a more complete story.

First-Generation vs. Second-Generation 3.5 EcoBoost

One of the mistakes people make when discussing Ford’s 3.5 EcoBoost is lumping over a decade of engines into a universal statement. The problem with that is that the second generation of the engine underwent a significant engineering evolution and has changed considerably.

For example, the second-generation 3.5 EcoBoost received dual port and direct fuel injection along with revisions to the valvetrain and cam drive. Changes were also made to the turbochargers. It was also paired with the 10-speed automatic in the F-150 trucks.

If the engine is newer, it doesn’t automatically mean it is problem-free. It just means it is different. It’s an important distinction to make, especially if you are researching timing-chain and cam-phaser concerns.

What Are the Most Common 3.5 EcoBoost Problems?

Each generation has different issues and the major issues on one generation aren’t necessarily the same on every generation.

Timing Chain Wear and Timing-Related Problems

The timing chain in the engine works to keep the crankshaft and camshafts in sync. That translates into the engine’s valves and pistons doing what they are supposed to do, when it is time to do it. If that relationship is not correct and things are out of sync, it can result in drivability concerns, abnormal noises, or diagnostic trouble codes.

Some first-generation 3.5-liter EcoBoost F-150s have legitimate timing-system issues. Ford issued TSB 18-2305, which covered certain 2011–2015 F-150s equipped with the 3.5-liter EcoBoost and built on or before May 29, 2015. The TSB described a ticking, tapping or rattling noise coming from the top or front-cover area of the engine during the initial start-up. The service procedure called for replacement of all four Variable Camshaft Timing units and the primary timing chain.

Cam Phaser Problems

Cam phasers are part of the variable valve timing system and allow the engine to adjust the camshaft timing as operating conditions change, which helps balance performance and efficiency. Issues with the cam phaser can sound like a distinctive rattle when starting the vehicle, but hearing the noise for two seconds doesn’t mean the engine is about to blow or there is an actual problem.

As Eric Shepherd, ASE-Certified Technician, explains:

“First measure would be to diagnose the cause of the noise. Noises are typically an easy and straight-forward initial approach. Fix the noise and retest.”

That approach is best because Ford itself tied cam-phaser concerns to specific vehicles.

Ford's Customer Satisfaction Program 21N03 covered certain 2017–2020 F-150, 2018–2020 Expedition and 2018–2020 Navigator vehicles equipped with the 3.5-liter EcoBoost GTDI engine. According to Ford, the issue produced an undesirable cam-phaser noise that could present as a rattle after the engine had been off for an extended period; once the engine was at a warm idle it could sound like a knocking noise. The fix is to replace all four VCT units when the issue was present.

It is important to note that 21N03 was part of a customer satisfaction program, not a safety recall.

Turbocharger Problems

Most of the muscle on the 3.5 EcoBoost comes from its twin turbochargers, which is also how the V6 was able to deliver an incredible amount of low-end torque that has made it popular in trucks. That said, turbo trouble can potentially reduce power or cause unusual noises, boost-related codes, smoke or evidence of oil or coolant leaks depending on the failure it is experiencing.

If you experience reduced power, it doesn’t automatically mean there is a problem with the turbochargers. It could be due to airflow issues, ignition problems or sensor faults, among other things.

Another important thing to note is that there is not a universal mileage for when the turbos on your 3.5 EcoBoost will go bad. It comes down to operating conditions, oil maintenance, engine condition and previous repairs.

Carbon Buildup

An issue that deserves some generation-specific context is carbon buildup. Early versions of the 3.5 EcoBoost use gasoline direct injection. In a direct-injection engine, the fuel is delivered directly into the combustion chamber rather than being sprayed upstream of the intake valve.

Later, second-generation versions added dual port and direct injection. Ford specifically documented the dual-injection strategy as one of the revisions to the second-generation engine, so carbon buildup conversations should be specific and focused, and not considered a universal problem.

Carbon buildup can contribute to rough running, reduced performance or other drivability symptoms, but those symptoms can have several possible causes. Carbon buildup can be one diagnostic consideration, but it should not be the automatic culprit just because your 3.5-liter EcoBoost isn’t running correctly.

Oil Consumption

All internal-combustion engines use some amount of oil, and the oil level can change between services. When dealing with an oil consumption issue, you might notice that your EcoBoost is smoking, see clear evidence of leaks, or find that the old oil level is surprisingly low when the vehicle arrives at the shop for an oil change. Turbocharged engines make oil maintenance especially important. The correct oil, the proper level and appropriate service intervals help protect components throughout the entire engine.

When it comes to a used vehicle, oil-change records can provide valuable insight. A stack of receipts in the glovebox may offer important clues about how the engine has been maintained throughout its life.

Ignition Problems and Misfires

If you experience an engine misfire, it can be one of those things that makes your expensive engine feel very broken, pretty quickly. But the good news is that not every engine misfire is an expensive problem to be solved. Sometimes all you need are some new spark plugs or ignition coils. Spark plugs are also normal maintenance components, not evidence of an inherent 3.5 EcoBoost issue.

Cooling-System Problems and Overheating

In Phoenix on a hot summer afternoon while you’re driving home from work, your cooling system health matters. Let’s be clear: Arizona heat doesn’t create any unique 3.5 EcoBoost issues that give it some kind of design defect. Like any vehicle subjected to a brutal Arizona summer, aging hoses, low coolant, leaks, or another cooling system problem can become more serious when ambient temperatures climb into the triple digits.

A good rule of thumb: if the temperature gauge begins moving somewhere it normally doesn’t, the coolant seems to disappear, or you smell coolant after parking, investigate it.

Which 3.5 EcoBoost Years Should You Avoid?

One of the most searched-for questions about the 3.5-liter EcoBoost is which years you should avoid. While there are model-year ranges with documented concerns worth paying extra attention to, it doesn’t mean every engine from those years is bad or that an engine outside of those years is an automatic safe buy.

Ford’s TSB addressing cold-start timing-system concerns was limited to certain 2011–2015 F-150s with a specific build cutoff. The later cam-phaser program covered specific 2017–2020 F-150s as well as 2018–2020 Expeditions and Navigators.

What Year Did the 3.5 EcoBoost Get Better?

There isn’t a magical number that separates the good 3.5 EcoBoosts from the bad. However, 2017 serves as an important milestone for the F-150 because that’s when Ford introduced its second-generation 3.5 EcoBoost architecture with engine revisions and dual port/direct fuel injection.

That said, some 2017–2020 F-150s were still included in Ford’s cam-phaser customer satisfaction program.

What Is the Most Reliable 3.5 EcoBoost Year?

Unfortunately, there isn't enough evidence to name one specific model year as the king of reliability when it comes to the 3.5 EcoBoost. If you find yourself comparing two used F-150s and one of those is a single model year newer, it won’t matter as much as the documented oil changes, repair history, a clean cold start, no active or pending diagnostic faults and evidence that the truck hasn't spent its entire life towing at maximum load with questionable maintenance. While service records aren’t the most exciting thing about a new-to-you vehicle, neither is spending your weekend broken down. Choose your excitement accordingly.

How Long Does a 3.5 EcoBoost Last?

Like any car and any engine, there isn’t a promise of a guaranteed mileage it will hit. Like all vehicles, the longevity of the engine will depend on how well it has been cared for. This includes things like maintenance history, oil quality and level, cooling-system health, ignition maintenance, towing and operating conditions, turbocharger condition, timing-system health, previous repairs and modifications.

What Should You Check on a High-Mileage 3.5 EcoBoost?

When inspecting a high-mileage 3.5 EcoBoost, don’t let the shiny paint job on the vehicle distract you from what happens when you push the start button or turn the key.

Eric Shepherd says the cold start is particularly valuable:

“The 3.5-liter EcoBoost engines are prone to their Cam Phaser rattle and failure along with Timing Chain stretch issues,” he said. “I would want to keep the vehicle long enough to listen on a cold start for any noises that may be a direct symptom to these common concerns.”

In other words, the ideal inspection begins before someone has already warmed up the car for you. Listen to the first startup, check the oil level and condition and look for fluid leaks, but don’t forget to inspect the rest of the vehicle. An F-150 with a healthy engine could possibly still need expensive transmission, driveline, suspension, brake or four-wheel drive work. Keep in mind that you are buying a full truck, not just the engine.

Does Towing Affect 3.5 EcoBoost Reliability?

F-150 owners use their trucks and the 3.5 EcoBoost was designed to work. As a result, Ford still offers the engine specifically for serious truck owners doing serious work. For example, the 2025 F-150 models equipped with the 3.5-liter EcoBoost can tow up to 13,500 pounds. Keep in mind that towing doesn’t mean you are abusing the truck. It’s just being used as intended and working harder than if it wasn’t towing.

Does Arizona Heat Affect the 3.5 EcoBoost?

As mentioned, the heat doesn’t automatically do something to the engine that makes it different or cause problems once it enters Arizona. Rather, the extreme ambient temperatures make it work harder and place stress on the cooling system, engine oil, battery, and the air conditioning system. Add towing or stop-and-go rush-hour traffic to the mix and your vehicle is now handling several major factors all at the same time.

For example, that small coolant leak might be easy to ignore during the hustle and bustle of work, school and daily life. It can quickly become an “I’ll get to it later” problem until you find yourself stuck on the side of the road.

Buying a Used Ford With the 3.5 EcoBoost? What to Check

Remember to buy the individual vehicle, not the reputation. A used vehicle with a 3.5-liter EcoBoost can still be a great, long-lasting and reliable vehicle for yourself and your family.

Just do your homework first. Here are a few easy steps to take:

• Confirm the exact model year and engine application.
• Review the vehicle’s maintenance and service history.
• Arrange to hear the engine from a genuine cold start.
• Check for warning lights or unusual engine noises.
• Look for oil or coolant leaks.
• Check for signs of excessive oil consumption.
• Scan for stored and pending diagnostic trouble codes.
• Evaluate misfire and boost-related data where appropriate.
• Ask about previous major engine repairs.
• Check for past turbocharger, timing-system or cam-phaser repairs.
• Ask about the vehicle’s towing history.
• Look for aftermarket tuning or other modifications.
• For applicable model years, check whether the VIN falls under any Ford TSBs or service programs and whether the relevant work has already been completed.
• Check the VIN through NHTSA for any open safety recalls.

And finally, opt for a pre-purchase inspection. You will want to discover all the potential issues while the truck still belongs to someone else.

The Bottom Line on Ford 3.5 EcoBoost Reliability

There is enough documented history about the 3.5-liter EcoBoost that owners and potential buyers should be aware of several documented concerns. But it also has enough revisions that blanket statements regarding the engine don’t cover it either.

For current owners, the best thing you can do is maintain the vehicle and pay attention to behavior changes so you can take care of small problems before they develop into larger problems.

If you are shopping for a used vehicle with the 3.5 EcoBoost, keep in mind that history matters. Listen for a clean cold start. Look for strong service records and a professional inspection should tell you much more about the vehicle than an internet list about “Five EcoBoost Years You MUST Avoid.”

Frequently Asked Questions About Ford 3.5 EcoBoost Problems

What are the most common 3.5 EcoBoost problems?

Documented concerns vary by generation and application but include timing-system/VCT concerns on certain earlier F-150s and cam-phaser noise on certain later F-150, Expedition and Navigator models. Ignition, turbo/boost and age-related maintenance problems can also produce drivability symptoms.

Is the Ford 3.5 EcoBoost reliable?

Reliability depends on generation, model year, maintenance history, operating conditions, previous repairs and the condition of the individual engine.

What years of the 3.5 EcoBoost should you avoid?

Buyers should pay particular attention to certain 2011–2015 F-150s covered by Ford's cold-start timing-system TSB and certain 2017–2020 F-150 and 2018–2020 Expedition/Navigator vehicles associated with Ford cam-phaser programs.

What year did the 3.5 EcoBoost get better?

For the F-150, 2017 marked an important transition to the second-generation 3.5 EcoBoost with significant engineering changes, but later vehicles still had their own documented concerns.

What is the most reliable 3.5 EcoBoost year?

There isn't one universally “most reliable” year. Condition, service history and application can matter more than choosing between two neighboring model years.

How long will a Ford 3.5 EcoBoost last?

There is no guaranteed mileage. Maintenance, operating conditions, towing, modifications and the condition of the timing, cooling, ignition and turbo systems all influence longevity.

Are 3.5 EcoBoost turbo problems common?

Turbochargers can develop problems, particularly as vehicles age, but reduced power or boost-related symptoms do not automatically prove turbocharger failure.

Is a high-mileage 3.5 EcoBoost worth buying?

Listen to a true cold start, review maintenance and repair records, check for leaks and diagnostic faults and have the vehicle professionally inspected before purchase.

Get Your Ford 3.5 EcoBoost Properly Diagnosed

Gemba Automotive can inspect and diagnose the problem before recommending the appropriate repair, with locations serving drivers throughout the Phoenix metro area.

Schedule an appointment and find out what's actually happening under the hood before a small concern becomes a bigger one.