3 Most Typical Ford 3.5 EcoBoost Engine Problems

by | Sep 14, 2021 | Ford | 0 comments

Engine: 3.5-liter EcoBoost Twin-Turbo V6

Ford The Lincoln MKS and MKT and the Taurus SHO, and the Ford Flex were all equipped with 3.5-liter EcoBoost engines when Ford introduced them in 2010. Afterward, the 3.5-liter twin-turbo V6 engine found its way into a variety of additional Ford and Lincoln vehicles over the next few years. With 354 to 648 horsepower and lots of torque, it’s a potent engine. Aside from that, turbochargers and direct injection enable the 3.5 V6 to maintain its fuel efficiency and emissions cleanliness. Ultimately, this 3.5 EcoBoost is indeed a fantastic engine. However, no engine is without flaws, and this is true in this case. In this post, we’ll go over some of the most frequent issues that drivers see with this Ford 3.5 EcoBoost V6, as well as the vehicle’s general dependability.

Background Information about the Ford 3.5 Twin Turbo V6

To properly understand the 3.5 EcoBoost issues, it is necessary first to provide some background information. There are two distinct versions of the 3.5 EcoBoost that we shall cover briefly further down in this section. There is a good reason why it is necessary to state the obvious. Ford did a good job modifying the 2nd generation 3.5 EcoBoost engine in the Focus RS. The upgrades aid in support of increased power and torque. They also solve a few dependability issues, making the Ford 3.5 dual-turbo engine of the 2nd generation considerably more dependable.

1st generation 3.5L EcoBoost engine

This is not to suggest that the 1st generation engine is poor in any way. On the other hand, Ford was pioneering a new path by merging turbos, fuel injection, and variable valve timing. As with any new vehicle, there are a few bugs to iron out, but with the 3.5 V6, they were quite minor. When we talk about typical 3.5L EcoBoost engine issues, we’ll go into more detail about this.

In any case, the 1st generation EcoBoost produces 355-380 horsepower depending on the car. Large amounts of low to mid torque are provided by the smaller twin turbos, quick to spool. The engine’s low RPMs make it a perfect choice for towing and having fun in town without the need to utilize the whole range of RPMs. The Ford and Lincoln vehicles that use the first generation 3.5 EcoBoost engine are as follows:

  • Ford Flex from 2010 until 2019.
  • Lincoln MKS from 2010 until 2016.
  • Lincoln MKT from 2010 until 2019.
  • Ford Taurus SHO from 2010 to 2019.
  • Ford Explorer Sport and Platinum models from 2013 to 2019.
  • Ford F-150 pickup trucks from 2011 to 2016.
  • Ford Expedition (2015-2017 model years)
  • Lincoln Navigator (2015-2017 model years)

2nd Generation 3.5-liter EcoBoost V6

In 2017, Ford started offering the 2nd generation EcoBoost in a limited number of vehicles. Most models receive an increase in power from 375 to 450 horsepower. On the other hand, Ford went a step further by developing a 647 horsepower version for the famous Ford GT. That motor, of course, gets some improvements over the regular 3.5 EcoBoost to handle the increased power.

Port-injection was also introduced in Ford’s second-generation 3.5 twin-turbo engines. This aids in the prevention of carbon build-up that we will explore more in the next section. Ford made additional changes to the timing chain due to unsatisfactory reliability issues with the prior design. Another topic that we will be delving into.

The 2nd generation engine may be seen in model types:

  • Ford F-150 from 2017 until the present
  • Ford Expedition (from 2018 to the present)
  • Ford F-150 Raptor from 2017 until the present
  • Lincoln Navigator from 2018 until the present
  • Ford GT from 2017 until the present

Three Common 3.5 EcoBoost Problems to Watch Out For

Now that we’ve covered most of the background info let’s get down to business with the real topic at hand. The following are some of the most often encountered problems with said Ford 3.5 Turbo engine:

  1. Carbon Dioxide Buildup
  2. Timing Chain (also known as timing chain)
  3. System of Ignition

As we just stated above, these top two issues are mostly related to the 1st generation 3.5 EcoBoost engine. Ford did an excellent job with the 2nd generation engine, addressing some of the problematic aspects. Once more the, 3.5 EcoBoost is a strong, dependable engine in its overall design. Two of the “problems” we listed above may not be considered difficulties in the traditional sense. Carbon build-up is just an unavoidable side effect of utilizing only direct injection. Turbocharging has several disadvantages, including increased wear and tear on ignition system components such as ignition systems and spark plugs.

Having said that, we’ll go into more detail about these 3.5 EcoBoost issues further down the page. Let’s take a couple of quick notes before we get started. However, just because we categorize these issues as frequent does not necessarily imply that they are prevalent in the vast majority of 3.5 V6 engines. Rather, these are a handful of the most often seen problems when anything goes wrong. Additionally, engines are susceptible to a slew of additional issues that we aren’t covering here – particularly as they age and accumulate miles.

1) Carbon Build-Up in the EcoBoost Intake Valve (3.5 liters)

Carbon buildup is mainly a source of worry for engines from the first generation. Direct injection (DI) is the sole fuel injection used in the first generation 3.5 EcoBoost, which means that fuel is blasted straight into the cylinders. As a result, carbon buildup on the intake ports develops over time as a result of this. Oil blow-by is a common occurrence in all engines to some degree. This oil finds its way along the intake tract, where it ultimately collects on the intake valves and cakes there. Fuel flowing over the intake valves and ports is an advantage of port injection over direct injection—this aids in removing oil deposits and preventing them from collecting.

However, when you have DI fuelling, there will be nothing to assist in cleaning the valves and ports of the engine. Carbon deposits accumulate in the cylinders over time, preventing air from flowing freely into them. Fortunately, it is not a serious problem that needs urgent treatment. Some DI engines are capable of running their whole lifetimes without requiring any valve cleaning. But carbon accumulation may cause power loss as well as a variety of other drivability problems.

Ford addressed this problem with the 2nd generation 3.5 EcoBoost by incorporating port and direct injection into the engine. In many respects, it’s the perfect combo since DI offers many advantages over PI. However, there are certain advantages to utilizing PI on its own, particularly in helping to avoid carbon build-up.

Symptoms of Carbon Build-Up in a Ford 3.5 TT V6

V6 Excessive carbon accumulation on the 3.5 V6 EcoBoost inlet valves and ports manifests itself as the following symptoms:

  • Misfires
  • Idle time is rough.
  • stuttering / hesitating / hesitancy
  • Loss of electrical power

The majority of these indications are a result of the primary problem at hand, which is misfires. Carbon deposits may cause uneven quantities of airflow to enter cylinders as a result of the deposits. This may cause the air-fuel mixture to become erratic, resulting in the 3.5 EB misfiring. As a result, symptoms such as error codes, harsh idle, and stuttering may appear. Carbon accumulation on the Ford 3.5L twin-turbo engine is another frequent symptom: a decrease in engine power. However, since carbon build-up happens over a lengthy period of time, it is often difficult to detect. Likely, you may not detect power loss that happens gradually over a period of many years.

“Fix” for the 3.5L EcoBoost Carbon Accumulation.

When the carbon formations become severe, you may want to try walnut blowing the intake ports to remove them completely. A high-quality shop vac, as well as walnut media shells, are required for the task. The rest of the time is spent mostly on the labor-intensive process of getting to the intake ports. This service is often provided at the cost of $400-600 or more. Therefore it is not inexpensive.

Unfortunately, it is not an urgent task that you must complete immediately, and you may even choose to avoid doing it altogether. Carbon deposits should not pose a significant threat to the 3.5 EcoBoost’s long-term reliability. We will still wish to take proper care of the task regardless of the circumstances. 99Walnut blasting is recommended to be performed every 71,000 to 100,000 miles as preventative maintenance.

2) Timing Chain Issues with the Ford 3.5 EcoBoost

Many specifics on the Ford 3.5 EcoBoost timing chain issues are hard to get your hands on. This is a problem that mostly affects engines from the first generation. More precisely, it seems to be limited to 3.5 EcoBoost engines manufactured between 2010 and 2014. Ford made improvements to the component before redesigning it for the second-generation 3.5L twin-turbo V6. Timing chain problems also seem to be more prevalent in the F-150 versions than in any other vehicle. However, it’s conceivable that this is just because the Ford F-150 is by far the most common model to be equipped with the EcoBoost engine.

As a result, the timing chain has been stretched, which is the problem at hand. Timing chain guides, tensioners, and cam phasers for the 3.5 EcoBoost engine have also been known to fail in certain instances. If a problem occurs with the timing chain assembly, it is recommended that the whole component be replaced. Ford, on the other hand, did publish a service bulletin in response to these issues. If you are out of warranty and have timing chain issues, you may be free to cooperate with Ford to resolve the issue.

These issues are usually urgent, and they should be addressed as quickly as possible once they arise. Additionally, it is conceivable that additional damage to the 3.5 Turbo EcoBoost engines will occur if the timing chain fails. Even though it is a very uncommon occurrence, you must address any problems with the timing chain as soon as possible.

Timing chain problems on the Ford 3.5L engine.

On the 3.5 EcoBoost, the following are some of the signs of guides, timing chain, tensioner, and cam phaser problems:

  • Rumble at the start of the race
  • DTC P0016 is a diagnostic trouble code.
  • The check engine light is illuminated.
  • Problems with driving abilities

One of the more frequent symptoms that may suggest that anything is wrong with the chain tensioner is rattling when the vehicle starts from a cold start. There are a variety of additional factors that may produce rattling, though. Also, keep an eye out for the 3.5 EcoBoost to generate the P0016 error code, which will also cause the check engine light to illuminate. Finally, when the timing chain strains, it may cause the ignition timing to be off, resulting in drivability problems. Misfires, power loss, harsh idle, and other issues fall into this category.

Timing Chain Replacement for the 3.5 Twin Turbo V6

It is not a simple or inexpensive task to replace the timing chain and other parts. It’s time-consuming, and the component prices may mount up quickly. While you’re there, you may want to try changing a few more minor things as well. Replacement of the timing chain is expected to cost in the thousands of dollars range.

Many defective 3.5 EcoBoost timing chains, on the other hand, were almost certainly changed at some point. The EcoBoost is prone to this issue, although it is not a problem that affects every engine. Some believe it is due to poor maintenance and oil change history, while others believe it is due to the use of 20w oils that are too lean for the engine. For their part, Ford has issued advisories to ensure that everyone is aware of the timing chain issues. Even if the warranty does not cover the problem, you may be able to negotiate with Ford to get discounts or other forms of alternative compensation.

3) Problems with the Ford 3.5 V6’s spark plugs and ignition coil

This is mainly because we’ve run out of other issues to discuss with the 3.5 EcoBoost at this point. It’s unlikely that referring to ignition coils and spark plugs as a “problem” is fair. Having a twin-turbocharged, direct-injection engine, on the other hand, is only half of the package. This is something we are quite acquainted with, having come from the BMW world. Turbochargers place a great deal of strain on the ignition system, exacerbated by the very high cylinder pressures experienced by turbos.

On naturally aspirated engines, spark plugs and ignition coils are typically good for 70,000 miles or more, with ignition coils often lasting nearly twice that. The ignition components on the 3.5-liter twin-turbo EcoBoost engine, on the other hand, will most certainly wear out considerably more quickly. Most of the time, it is simply normal depreciation, but there is the possibility of more serious issues. On any engine, and the 3.5L EcoBoost V6 from Ford is no exception, this is rather a straightforward operation.

Ignition components may create a wide range of issues and other drivability issues, so don’t dismiss basic spark plugs or coils as a source of concern. Spark plugs for stock 3.5 Turbo EcoBoost motors will most likely need to be replaced every 45,000 to 55,000 miles. Anticipate the ignition coils to last approximately twice as long as the originals. If you’re running a tune, installing modifications, or running the 3.5 EcoBoost aggressively, you may significantly reduce the lifetime of the ignition components. We need to replace the spark plugs in our dual-turbo 335i with the N54 engine every 10,000 miles since modified. If we’re fortunate, ignition coils will last for 25,000 miles before needing to be replaced.

Symptoms of a 3.5 EB Spark Plug and Ignition Coil

The following are signs that an ignition coil or spark plug is on its way out:

  • Misfires Idle stuttering Rough idle
  • The check engine light is illuminated (misfire codes)

The same symptoms often characterize plugs and coils. We usually suggest replacing all ignition coils or six spark plugs simultaneously; this is particularly true if it has been a long time since you last replaced them in your vehicle. If you have misfires, here’s a simple method to determine whether the spark plug or coil is the problem. Investigate the trouble codes to identify which cylinder (or cylinders) is causing the problem. Remove the ignition coil from the misfiring cylinder and replace it with an ignition coil from a cylinder that is not backfiring. If the misfire continues after the replacement cylinder is installed, you have identified the source of the problem.

If it does not work, you may try the EcoBoost spark plugs to see if that works better. You could also try just changing the spark plugs as a matter of course. It is a simple and inexpensive fix.

Ford 3.5L Spark Plugs and Coils Installation

Once again, the technique described above is an excellent way to identify where the problem is coming from. The spark plugs are often to a fault since their life span is much less than that of the ignition coils. Luckily, a set of six Ford 3.5 spark plugs is typically available for about $40 and $100, dependent on where you purchase the components. A simple task that can be completed in the yard in much less than 2 hours by almost anybody with basic tools.

A bundle of ignition coils is a little more expensive, ranging between $200 and $300. However, it is a far simpler task than replacing the spark plugs. You may do this on your own, or if you prefer, you can take it to a repair shop, where labor should be around $100.

Ford 3.5 EcoBoost Reliability & Dependability

Is indeed the Ford 3.5 Twin Turbo EcoBoost engine a dependable motor? Yes. When it comes to dependability, we think the Ford 3.5 twin-turbocharged engine gets above-average ratings. Fortunately, there aren’t many typical problems that arise with these engines. Additionally, Ford did an excellent job with the 2nd generation 3.5 EcoBoost in resolving some of the issues they had raised before.

Of fact, in certain instances, the reliability of every 3.5 V6 engine is determined by sheer luck. The truth is that it is one of the variables over which we have no control. You do, however, have some influence over how well the dual-turbo EcoBoost engine is maintained. Oil changes should be performed on schedule, with high-quality oils being used, and You should address issues as soon as they arise.

Proper care of a 3.5 EcoBoost will almost certainly result in a pleasant and dependable driving experience. Turbo engines may require a little more upkeep, but we believe the effort is worthwhile in the long run. Power, torque, fuel economy, and towing capacity are all great characteristics of Ford EcoBoost engines. For the most part, most 3.5L 6-cylinder EcoBoost engines should have no significant problems lasting 200,000 miles or more. Not too shabby in terms of lifespan.

Final Thoughts on the 3.5 EcoBoost Common Problems

Without intending to disparage the Ford 5.0 Coyote engine, we think that the 3.5 EcoBoost engine is the obvious pick if you have the choice. The Ford 3.5 EB provides an excellent combination of torque, power, towing capacity, economy, and other characteristics. The use of two turbos also opens the door to a plethora of tuning possibilities for those looking to get even more performance out of their motors. The 3.5 EcoBoost is a fantastic engine, but no engine is without flaws.

Engines from the first generation of engines have had issues with carbon buildup and timing chain failure. Timing chain problems are probably not as prevalent as some people would have you think, but they are something that owners ought to be aware of. Direct injection also naturally results in carbon deposits on the intake ports, impairing the engine’s ability to perform well under load. Once Ford became aware of the problems, they did an excellent job of addressing them.

Otherwise, it’s essential to remember that turbo engines may be more difficult to maintain than conventional engines. Because of the high turbo boost pressures, the ignition coils and spark plugs are damaged. Turbocharged engines, such as the Ford 3.5 EcoBoost, have many moving components that may fail. Despite this, turbo technology has advanced significantly during the last several decades. Care for your Ford EcoBoost V6 engine properly, and you will most likely be rewarded with a dependable and enjoyable driving experience.

See our article on the Ford 2.7 Ecoboost Common Engine Problems

Dmitry Petrov

Dmitry Petrov is an engineer who specializes in materials science, and has a deep passion for all things related to automotive technology. He is a true motorhead at heart, and spends much of his free time tinkering with engines and studying vehicular dynamics.


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