P0304 on Lincoln: How to Diagnose & Fix
Cylinder 4 Misfire Detected
3 Lincoln models · 3 documented issues · 1 critical · $100-$8,000 repair
P0304 on Lincoln by model: symptoms, diagnosis and fix
2016-2017 Lincoln MKX models with the 2.7L EcoBoost V6 (engines built roughly April 2016 to January 2017) can suffer excessive oil consumption caused by defective cylinder head valve guides that let oil seep into the combustion chamber and burn off. Owners report burning roughly a quart every 3,000 miles, often accompanied by rough idle, misfires, and blue/white exhaust smoke. Ford addressed this in Technical Service Bulletin 19-2243, whose official remedy is replacement of both left and right cylinder heads. Fouled spark plugs from oil contamination commonly trigger cylinder-specific misfire codes.
Common Symptoms
- excessive oil consumption (1 quart per ~3000 miles)
- rough idle
- engine misfire
- blue or white exhaust smoke
- fouled spark plugs
- low oil warning between changes
How to Fix
Have the dealer confirm coverage under TSB 19-2243; the corrective procedure replaces both cylinder heads (and typically spark plugs). Monitor oil level frequently between services and document consumption to support a warranty/goodwill claim.
Sources for this issue (3)
- TSB 19-2243 (NHTSA MC-10164421): 2.7L/3.0L Oil Consumption With DTC P0524/P06DD, Rough Idle, Misfire, White or Blue Exhaust Smoke - 2016-2017 Edge/MKX, 2017 Continental/Fusion/MKZtsb
- Oil Consumption With DTC P0524 and/or P06DD - 2016-2017 Ford & Lincoln (OEMDTC)tsb
- Ford 2.7 EcoBoost Engine Specs, Problems, Reliabilityarticle
The 1998-up 4.6L 2V V8 uses eight individual coil-on-plug ignition coils whose boots and towers crack with age and heat, allowing spark to track to ground and causing single- or multi-cylinder misfires, rough idle, and stumbling under load. Failures are accelerated when the 1996-2001 plastic intake manifold leaks coolant into the spark plug wells and shorts the coils. It is one of the most common drivability complaints on the platform, well documented across owner forums and diagnostic guides.
Common Symptoms
- Check engine light, sometimes flashing, with misfire codes
- Rough or shaking idle
- Stumble or jerking under acceleration or load
- Reduced power and fuel economy
- Misfire worse in damp weather
How to Fix
Diagnose by swapping the suspect coil to another cylinder and confirming the misfire code follows; replace failed coils and boots, and replace high-mileage spark plugs at the same time. If coolant is found in a plug well, fix the intake manifold leak first or the new coil will fail too.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Motorcraft DG-508 ignition coil, singleOEMMotorcraft DG-508
Replace one coil confirmed failed on the 1998-2011 4.6L Town Car branch Fitment/availability: Live direct page identifies Motorcraft DG508, Town Car fitment and Add to Cart. Quantity is one per confirmed failed cylinder; confirm the vehi…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (4)
- Lincoln Town Car P0301: Cylinder 1 Misfire (Causes + How to Fix) — Drivetrain Resourcearticle
- How To Test The Coil-On-Plug Ignition Coils (1998-2011 4.6L Crown Victoria, Grand Marquis) — identical Panther 4.6L powertrain as Town Cararticle
- Ford DG508 Ignition Coil Failure: Misfires in 4.6L & 5.4L V8s (names Crown Victoria, Town Car, Grand Marquis) — Go-Partsarticle
- Cracking Intake Settlement (96M91/97M91 + class action, 1996-2001 4.6L incl. Town Car) — TCCoA Forumsforum
P0304 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0304 mean on a Lincoln?
P0304 stands for "Cylinder 4 Misfire Detected." This code means the engine computer detected a misfire in cylinder number 4 — that cylinder isn't igniting its air-fuel mixture fully or at all. The system detects this by monitoring small changes in crankshaft rotation speed as each cylinder fires. You may feel a rough idle, shaking, hesitation or reduced power, and a persistent misfire can dump unburned fuel into the exhaust and overheat or damage the catalytic converter. Since it's pinpointed to one cylinder, the problem typically lies in that cylinder's spark, fuel, or compression. On Lincoln it is documented across 3 models: Navigator, MKX, Town Car.
What are the most common causes of P0304?
The most common causes of P0304 are: Worn or fouled spark plug in cylinder 4, Failed or weak ignition coil on cylinder 4, Faulty spark plug wire or boot (where applicable), Clogged, stuck or leaking fuel injector for cylinder 4, Vacuum or intake air leak near that cylinder, Low compression (worn rings, burnt/leaking valve, head gasket), Damaged wiring or connector at the coil or injector. The specific cause varies by vehicle.
How much does it cost to fix P0304 on a Lincoln?
Published repair estimates on Lincoln range from $100 to $8,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0304 on a different make?
View P0304 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.