What Vehicles Fit UF646 Ignition Coils?
According to the supplied fitment information, these coils fit selected 3.5L EcoBoost V6 applications.
Ford F-150
2011–2016 Ford F-150 – 3.5L EcoBoost V6
The F-150 is one of the most important applications for this coil set.
A weak ignition coil on a turbocharged 3.5L can become particularly noticeable under boost when cylinder pressures increase.
Symptoms may include:
- Misfire while accelerating
- Rough running under boost
- Loss of power
- Check Engine light
- Flashing Check Engine light
- Poor fuel economy
Ford Expedition
2015–2017 Ford Expedition – 3.5L EcoBoost V6
Expedition owners may notice ignition problems most when the engine is heavily loaded, such as during towing, highway acceleration or climbing grades.
Ford Explorer
2013–2019 Ford Explorer – compatible 3.5L EcoBoost applications
Pay particular attention to engine configuration here.
Not every Explorer equipped with a 3.5L V6 is an EcoBoost application, and not every Explorer should automatically be assigned this coil based solely on displacement.
Verify the coil number before ordering.
Ford Flex
2013–2019 Ford Flex – compatible 3.5L EcoBoost applications
The twin-turbocharged 3.5L was offered in performance-oriented Flex configurations, making reliable spark particularly important under boost.
Ford Taurus
2013–2016 Ford Taurus – compatible 3.5L EcoBoost applications
This primarily concerns EcoBoost performance applications such as the Taurus SHO rather than every Taurus equipped with a V6.
Again: verify the engine.
Ford Police Interceptor Sedan
2013–2019 Ford Police Interceptor Sedan – compatible 3.5L EcoBoost applications
Police applications can accumulate substantial idle time and thermal cycles, which makes ignition-system condition particularly important on higher-mileage vehicles.
Ford Police Interceptor Utility
2014–2019 Ford Police Interceptor Utility – compatible 3.5L EcoBoost applications
Confirm the vehicle is equipped with the applicable EcoBoost engine before ordering.
Ford Transit
Listed applications include:
- 2015–2020 Ford Transit-150
- 2015–2020 Ford Transit-250
- 2015–2020 Ford Transit-350
- 2015–2020 Ford Transit-350 HD
These listings apply to compatible 3.5L EcoBoost V6 configurations.
Do not assign UF646 coils to every Transit from these years because Ford offered multiple engines.
Ford Lobo
2015–2020 Ford Lobo – compatible 3.5L EcoBoost applications
Lobo is the name used for certain F-150 configurations in the Mexican market.
Lincoln MKS
2013–2016 Lincoln MKS – compatible 3.5L EcoBoost V6
Lincoln MKT
2013–2016 Lincoln MKT – compatible 3.5L EcoBoost V6
Lincoln Navigator
2015–2017 Lincoln Navigator – 3.5L EcoBoost V6
The Navigator application shares the same basic need as the Expedition: reliable ignition under substantial vehicle load and boost.
Why Ignition Coils Matter More Under Boost
An ignition coil has one basic job:
Provide enough voltage to create a reliable spark across the spark-plug gap.
Turbocharging makes that job harder.
When the EcoBoost turbochargers increase intake-manifold pressure, more air enters the cylinders. Cylinder pressure rises accordingly.
Higher cylinder pressure makes it more difficult for the spark to jump the plug gap.
That’s why a marginal coil can behave perfectly well while the engine is:
- Idling
- Cruising
- Driving gently
and suddenly begin misfiring when you put your foot down.
A 3.5 EcoBoost that stutters under boost doesn’t automatically need coils, but the ignition system absolutely belongs on the diagnostic list.
Symptoms of a Bad 3.5 EcoBoost Ignition Coil
Common symptoms include:
- Rough idle
- Engine misfire
- Hesitation
- Stuttering under boost
- Loss of power
- Poor acceleration
- Check Engine light
- Flashing Check Engine light
- Reduced fuel economy
- Hard starting
- Shaking during acceleration
For a deeper diagnostic explanation, read Pro Street’s live 7 Bad Ignition Coil Symptoms You Should Never Ignore guide.
It explains how failing coils can produce rough idle, misfires, hesitation and power loss without assuming every drivability problem is automatically an ignition coil.
P0300 and EcoBoost Misfires
A failing ignition component may trigger:
P0300 – Random/Multiple Cylinder Misfire Detected
or cylinder-specific codes such as:
- P0301
- P0302
- P0303
- P0304
- P0305
- P0306
Pro Street’s live P0300 Random/Multiple Cylinder Misfire Causes & Fixes guide explains why a P0300 should be diagnosed rather than immediately translated into “buy ignition coils.”
Possible causes include:
- Ignition coils
- Spark plugs
- Injector problems
- Fuel-delivery faults
- Intake leaks
- Wiring problems
- Compression problems
- Other mechanical failures
How to Test a Suspected EcoBoost Coil
A cylinder-specific misfire gives you a useful starting point.
Suppose your 3.5 EcoBoost has:
P0303 – Cylinder 3 Misfire
One simple diagnostic strategy is:
- Record the trouble code and freeze-frame information.
- Remove the ignition coil from cylinder three.
- Move that coil to another cylinder.
- Install a known-good coil into cylinder three.
- Reassemble everything properly.
- Run the engine.
- Monitor misfire data.
- Rescan the PCM.
If the misfire moves with the coil, the coil becomes a strong suspect.
If P0303 remains on cylinder three, keep diagnosing.
That’s considerably cheaper than replacing six coils because a $10 spark plug was having a bad afternoon.
Spark Plugs Are Especially Important on Turbo Engines
Don’t install new coils and ignore worn spark plugs.
Spark-plug gap directly affects the voltage required to create a spark.
As the electrodes wear and the gap increases, the ignition system must work harder.
Combine that with elevated cylinder pressure under boost and marginal ignition components can begin misfiring.
Inspect the plugs for:
- Excessive gap
- Electrode wear
- Carbon deposits
- Fuel fouling
- Oil contamination
- Cracked porcelain
- Carbon tracking
- Evidence of overheating
For modified or higher-boost applications, plug selection becomes even more important.
Pro Street’s live Best Spark Plugs for Turbo Cars That Deliver content and How to Pick Spark Plugs for Your Build guide provide additional information about heat range, boost and ignition requirements.
Why Does My EcoBoost Misfire Only During Acceleration?
This symptom deserves its own section because it’s extremely relevant to turbocharged engines.
If your EcoBoost:
idles normally → cruises normally → misfires when boost builds
look closely at the ignition system.
Higher cylinder pressure increases the voltage necessary to bridge the spark-plug gap.
Potential causes include:
- Weak ignition coil
- Excessive spark-plug gap
- Worn spark plug
- Damaged coil boot
- Carbon tracking
- Poor coil connection
But don’t forget fuel delivery and boost-related problems can produce similar symptoms.
Diagnosis still wins.
Should You Replace One EcoBoost Coil or All Six?
This NPAUTO package contains six ignition coils, enough for a complete compatible V6.
Replacing all six can make sense when:
- Mileage is high
- All coils are original
- Multiple coils have failed
- Several coils show deterioration
- You’re replacing all six spark plugs
- You’re performing a complete ignition refresh
Replacing one coil can make sense when:
- One coil has conclusively failed
- The remaining coils are relatively new
- Only one component tests faulty
A complete set is convenient.
It isn’t a medical mandate.
Inspect the Coil Boots
When removing the coils, inspect the rubber boots carefully.
Look for:
- Cracks
- Tears
- Oil contamination
- Water intrusion
- Carbon tracking
- Burn marks
- Corrosion
Carbon tracking can create an electrical path along the outside of the spark-plug insulator.
That can cause repeat misfires even after parts are replaced if the underlying contamination isn’t addressed.
EcoBoost F-150 Owners Who Tow
Ignition-system maintenance becomes particularly important when an F-150 is used for towing.
Towing increases engine load.
More load means the turbochargers work harder.
More boost means higher cylinder pressure.
And higher cylinder pressure increases ignition demand.
A marginal coil or badly worn spark plug may therefore reveal itself while:
- Pulling a trailer
- Climbing a grade
- Passing
- Accelerating onto a freeway
even though the truck drives perfectly well unloaded.
Don’t Ignore a Flashing Check Engine Light
A severe misfire can allow unburned fuel to enter the exhaust system.
That fuel can overheat the catalytic converter and cause expensive damage.
If the EcoBoost is shaking badly and the Check Engine light begins flashing, reduce load and address the problem promptly.
A misfire that started with an ignition component doesn’t need a catalytic converter as a supporting character.
UF646 vs. DG549
This coil is commonly referenced through several interchange numbers, particularly:
UF646 / DG549
Additional supplied references include:
BL3Z-12029-C, BL3Z12029A, BL3Z12029B, IC749, E1146, 5C1871 and 673-6300.
Use the original coil number, engine information and vehicle application together when confirming fitment.
Who Should Buy This UF646 Six-Coil Set?
This package is particularly attractive for compatible:
- Ford F-150 3.5 EcoBoost
- Ford Expedition 3.5 EcoBoost
- Ford Explorer 3.5 EcoBoost
- Ford Flex 3.5 EcoBoost
- Ford Taurus SHO
- Ford Transit 3.5 EcoBoost
- Lincoln MKS EcoBoost
- Lincoln MKT EcoBoost
- Lincoln Navigator 3.5 EcoBoost
where all six coils are being replaced together.
Is the NPAUTO UF646 Coil Set Worth It?
For a compatible Ford or Lincoln 3.5L EcoBoost V6, this six-piece UF646 ignition coil set offers a convenient way to replace the complete coil-on-plug ignition system.
That’s particularly useful for higher-mileage EcoBoost engines where multiple original coils are beginning to deteriorate.
Combine correctly functioning coils with properly selected and properly gapped spark plugs and the EcoBoost ignition system can reliably handle the increased cylinder pressures created under boost.
Just diagnose the engine before ordering.
Because “EcoBoost misfire” isn’t a part number.
There are no reviews yet.