Buy Ford Transit-350 Direct Ignition Coils

• Job: Boosts battery voltage so spark plugs ignite fuel. (Wikipedia)
• Design: Coil‑on‑plug system-one coil per cylinder-used on 3.5 L EcoBoost and 3.7 L Ti‑VCT V‑6 engines in Transit‑350 models built 2015‑present.
• No Coil on Diesel: The optional 3.2 L Power Stroke diesel relies on compression ignition, so it has glow plugs instead of spark coils.
• Torque Spec: Ford workshop data lists the coil mounting bolt at 7 Nm (62 in‑lb) on the 3.7 L engine; always use a beam or click torque wrench. (s197.lima-city.de)
• Typical Life: Quality coils often last 80 000-100 000 miles before weakening. (Capital One)

Each coil contains two copper windings wrapped around an iron core. When the engine computer switches the primary winding on and off, a magnetic field collapses and jumps the voltage up to roughly 20 000-40 000 volts. The spark then leaps the plug gap and lights the mixture. Modern coil‑on‑plug setups cut energy loss found in older distributor systems, boost efficiency, and simplify diagnostics. (Wikipedia)

← scroll table horizontally →

Motorcraft's long‑running DG‑542 family coil is the common service part number for both gasoline V‑6 engines (part numbers may carry prefix changes over the years, but internal specs remain alike). (Bob Is The Oil Guy)

• Engine shakes or jerks at idle or under load. (Firestone Complete Auto Care)
• Drop in fuel economy and sluggish throttle. (Capital One)
• Illuminated MIL with codes such as P0300 (random misfire) or cylinder‑specific codes P0301‑P0306. (OBD-Codes.com, OBD-Codes.com)
• Hard starting on damp mornings-often tied to water dripping onto rear coils on low‑roof vans.

1. Scan with any OBD‑II reader to pull misfire (P030x) or coil‑primary circuit (P035x) codes. (OBD-Codes.com)
2. Swap the suspect coil to another cylinder; if the misfire code moves, the coil is bad.
3. Check for water ingress. Ford TSB 18‑2321 adds a cowl deflector and wiper‑arm grommet to keep rainwater off the coils.
4. Use a spark‑tester or oscilloscope for deeper waveform checks if needed.

• Mileage Rule‑of‑Thumb: Inspect coils when plugs are replaced (Ford recommends 60 000‑mile plugs on EcoBoost; many owners change coils together once past 100 000 miles). (danggoodlife.com, Capital One)
• Bolt Torque: Tighten COP bolts to 62 in‑lb (7 Nm). Over‑torque may crack the housing. (s197.lima-city.de)
• Use Dielectric Grease: A thin film in the rubber boot helps seal out moisture and eases future removal.
• Always Reset Codes: Clear stored DTCs after repair and road‑test for at least one full warm‑up cycle.

Ford's October 2018 bulletin warns that early 2015‑2018 vans may misfire because water drips onto the right‑side coils; the repair kit adds a foam seal, new air‑cleaner cover, and wire‑loom retainer. Staying current on TSBs ensures any coil‑related drivability complaints are fixed the first time.

Plugs and coils sit on top of the aluminum cylinder heads under the intake plenum. Videos walk through removal in minutes once the intake tube is off. (YouTube, YouTube) Basic steps:

1. Disconnect battery.
2. Unclip coil connector, remove 8 mm bolt, twist coil, and lift straight up.
3. Blow out spark‑plug well, then pull the plug.
4. Install new plug (12 ft‑lb / 16 Nm) and re‑seat coil with fresh boot.
5. Re‑torque, reconnect, and clear codes.

Misfires caused by weak coils waste fuel, raise hydrocarbon emissions, and can overheat catalytic converters. Timely coil replacement keeps the Transit‑350's 3‑ton footprint running cleaner and saves owners money at the pump. (Firestone Complete Auto Care)

Q: How many ignition coils does a Transit‑350 have?
A: Gas models use six coil‑on‑plug units-one on each cylinder bank.

Q: Does the diesel Transit use these coils?
A: No. The 3.2 L diesel ignites fuel by compression and relies on glow plugs, not spark coils. (Wikipedia)

Q: What trouble codes point to a bad coil?
A: Random misfire P0300 or cylinder‑specific misfire codes like P0302 point toward the coil or plug on that cylinder. (OBD-Codes.com, OBD-Codes.com)

Q: What is the correct bolt torque?
A: Tighten the coil bolt to 7 Nm (62 in‑lb). (s197.lima-city.de)

Q: How long do factory coils last?
A: Many reach 80 000-100 000 miles, but heat, moisture, and gap‑widened plugs can shorten life. (Capital One)

Q: Can I drive with a misfiring coil?
A: It may limp, but unburned fuel can quickly damage the catalytic converter, so fix the issue right away. (Firestone Complete Auto Care)

Q: Should I replace all coils at the same time?
A: If one fails past 80 000 miles, many techs suggest changing the full set to avoid repeated labor later. (Capital One)

Q: Why do coils on low‑roof vans fail more often?
A: Ford linked water dripping through the cowl onto rear coils; a deflector kit cures the leak.

Q: What gap should replacement spark plugs be set to?
A: 3.7 L: 1.25-1.35 mm (.049-.053 in); 3.5 L EcoBoost: 0.75-0.85 mm (.030-.033 in). (Ford Service Content)

Q: Will a bad coil hurt fuel economy?
A: Yes-misfires waste fuel and lower power, often trimming mileage by several MPG. (Firestone Complete Auto Care)

Q: Does Ford have an extended warranty for coils?
A: Powertrain coverage is 5 years/60 000 miles, but owners can buy Ford Protect plans for longer ignition‑system coverage. (Ford Motor Company)

Q: What basic tools do I need for the job?
A: 8 mm socket, 3/8‑in torque wrench, dielectric grease, and a scan tool to reset codes. DIY videos show the steps clearly. (YouTube)

Replacing worn coil packs on a Transit‑350 is a straightforward job that restores smooth power, protects the catalytic converter, and keeps the big van ready for work.