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Ford 3.5 EcoBoost Engine Problems

in Reliability
Photo of Ford Ecoboost 3.5L engine

Ford Ecoboost 3.5 by Numobeer - CC-BY-SA-4.0

Ford’s EcoBoost line of engines has become synonymous with the effective combination of power and fuel efficiency. The 3.5L V-6 variant lives at the lineup’s center and offers prodigious power to everything from the Fusion sedans to F-150 trucks. In general, the 3.5L Ecoboost continues to grow its fan base due to its strength and durability. Still, some issues remain common on a few variants of this engine.

This article will dig into the common Ford 3.5 EcoBoost engine problems and detail the issues and how much it will cost to repair them.


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The Most Common Ford 3.5L EcoBoost Problems:

  • Intercooler Condensation. Cost to fix: $500
  • Timing Chain Wear. Cost to fix: $2000
  • Ignition Issues. Cost to fix: $450
  • Carbon Buildup. Cost to fix: $400-600

Intercooler Condensation 


In high humidity conditions, some models of F-150 have issues with water being trapped (vs. vaporized) in the intercooler. This is due to a design flaw that does not allow water to be quickly evaporated in high humidity conditions. This can cause stumbling or hesitation under high boost loads or highway speeds. Ford redesigned this part in later years to avoid the issue. 


The aftermarket offers a solution for this problem via an apparatus called a “catch can.” Essentially, these devices use the vacuum created by the turbos to catch oily water vapor from the intercooler. These rigs run from $200 to $400 and can easily be installed by a mechanic for around $150.


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Timing Chain Wear


Since the Ecoboost is a turbocharged engine, it is even more imperative to maintain due to the stress that the oil is consistently under. If maintenance is not kept up, the timing chain can wear out prematurely, along with the chain tensioner and pulleys. Once this happens, the engine will fall out of timing alignment and experience many issues. 


Unfortunately, this is an expensive repair as it requires a good bit of engine teardown to accomplish the task of replacing the timing chain parts and pieces—figure north of $2,000 for this intensive job. 

Ignition Issues


One of the side effects of the turbo in the Ecoboost engine is heavier carbon buildup on the ignition coil. Once this happens, the engine can suffer from misfires and stumbling upon acceleration. Search TSB 14-0180 for more information on Ford’s recommended course of action, including replacing the ignition pack. 


This job is similar to performing a tune-up and typically runs anywhere from $400 to $450 at a reputable mechanic.

Carbon Buildup


Carbon build is primarily a concern on 1st-gen EcoBoost engines. The first-generation EcoBoost engines only use direct injection, meaning the fuel is sprayed straight into the cylinders. As a result, carbon can accumulate inside the valve intakes. While it’s normal for engines to experience oil blow-by, it’s particularly bad in 1st-gen EcoBoosts since nothing helps clean the ports and valves.

This results in carbon buildup that restricts airflow into the cylinders. While this issue doesn’t strictly require immediate attention, it may lead to drivability issues like power loss, misfires, and rough idling.

Again, this was mainly a concern with first-generation EcoBoost engines. Ford corrected this design flaw with the second-gen 3.5 EcoBoost.


The best approach is not to allow the carbon to accumulate so bad that it causes problems. However, once the buildup becomes excessive, an effective fix is to conduct walnut blasting. This solution requires a good-quality shop vac and walnut media shells. Including labor, you may have to pay $400-600+ for this fix. Unless you know what you’re doing, it’s better to let the professionals handle this job.


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Avoiding the Ford 3.5L Engine Problems

Many of the issues listed on this page can be caught if you are mechanically savvy and know what to listen for when test driving a vehicle equipped with this engine. For the rest of us, get a pre-purchase inspection from a local mechanic.

Most mechanics offer inspections for vehicles that include a complete visual examination and full diagnostic. That pesky timing chain or misfiring cylinder might be missed during a test drive but will be found during a pre-purchase inspection.

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