P0306 on 2017 Lincoln Continental: Cylinder 6 Misfire Causes and Fixes

What's Unique About the 2017-2017 Lincoln CONTINENTAL

For the 2017 Lincoln Continental, especially models with the 2.7L and 3.0L twin-turbo engines, a P0306 code can be far more serious than a simple ignition problem. Manufacturer Technical Service Bulletins (TSBs) directly link this misfire code to significant internal engine problems stemming from defective valve guides. 🎬 Watch: Mechanic explains the top 5 issues with this engine. Specifically, if the misfire is accompanied by excessive oil consumption, the cause is very likely faulty cylinder heads or may even require a complete long-block engine replacement. This elevates the diagnostic importance of a P0306 code beyond what is typical for many other vehicles.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Rough or shaking idle
• Hesitation or stumbling during acceleration
• Noticeable loss of engine power
• Solid or flashing Check Engine Light
• Decreased fuel economy
• Smell of fuel from the exhaust
• White or blue smoke from the exhaust, especially after a hot restart (indicates oil consumption and likely internal engine issue)

Most Likely Causes

1. Ignition Coil Failure 🔴 High Probability → Shop Ignition Coil Coil-on-plug systems are common failure points on many modern engines due to constant exposure to heat and vibration.
   How to confirm: Swap the ignition coil from cylinder 6 with another cylinder (e.g., cylinder 5). Clear the codes and run the engine. If the code changes to P0305, the coil is faulty. Cylinder 6 is located on the front bank (radiator side) on the driver's side of the engine.
   Typical fix: Replace the faulty ignition coil. It is often recommended to replace all six coils and spark plugs at the same time as preventative maintenance.
   Est. part cost: $70-$120 per coil
2. Worn or Fouled Spark Plug 🔴 High Probability → Shop Spark Plug Spark plugs are a regular maintenance item. The turbocharged 2.7L and 3.0L engines are particularly sensitive to spark plug condition and gap, which should be checked and set precisely.
   How to confirm: Remove the spark plug from cylinder 6 and inspect it for wear, carbon fouling, oil contamination, or a cracked insulator. An oil-fouled plug is a strong indicator of the more serious internal engine problem. Check the gap to ensure it meets specifications.
   Typical fix: Replace the spark plug. It is best practice to replace all six spark plugs as a set. 🎬 Watch: Step-by-step guide to replacing spark plugs on the 2.7L.
   Est. part cost: $10-$25 per plug
3. Internal Engine Fault (Cylinder Head/Long Block) 🟡 Medium Probability TSBs SSM 54504, SSM 46364, and 19-2243 specifically identify this issue for 2017 models with 2.7L/3.0L engines built between April 2016 and January 2017. The root cause is often defective valve guides which wear, allowing oil to leak into the cylinders, causing consumption, fouling, and misfires.
   How to confirm: Perform a cylinder compression test and a leak-down test on cylinder 6. Low compression points to a mechanical issue. The presence of codes P0524 (Engine Oil Pressure Too Low) or P06DD (Engine Oil Pressure Control Circuit Stuck Off) alongside the misfire strongly suggests a major engine problem requiring long block replacement. [8, 13, TSB SSM 54504, TSB SSM 46364]
   Typical fix: This is a major repair requiring professional service. Per the TSBs, if oil pressure codes are not present, the fix is cylinder head replacement. If oil pressure codes ARE present, a complete long block engine replacement is required.
   Est. part cost: $2000 - $8000+
4. Faulty Fuel Injector ⚪ Low Probability → Shop Fuel Injector
   How to confirm: Listen for a clicking sound from the injector with a mechanic's stethoscope. A more advanced method is to swap the injector with another cylinder to see if the misfire code follows, though this is more labor-intensive than a coil swap. TSB 18-2310 also notes faulty direct injectors as a cause for misfires on some 2.7L EcoBoost engines.
   Typical fix: Replace the faulty fuel injector.
   Est. part cost: $50-$150

Rare But Worth Checking

• Vacuum Leak: A vacuum leak from a cracked hose or a leaking intake manifold gasket near cylinder 6 can lean out the air/fuel mixture and cause a misfire.
• Low Fuel Pressure: A weak fuel pump or clogged fuel filter can cause a lean condition and misfires, though this would typically affect multiple cylinders and trigger other codes like P0300 (Random Misfire).

Diagnosis Steps

1. Read the trouble codes with an OBD-II scanner and note any other codes present, paying close attention to P0300, P0316, P0524, or P06DD.
2. Check for excessive oil consumption (more than 1 quart per 3,000 miles) and observe the exhaust for blue or white smoke, as these are key indicators of a more serious issue on this vehicle.
3. Identify Cylinder 6: On all V6 engines for this vehicle, it is the cylinder at the front of the engine bay (radiator side), closest to the driver's side.
4. Swap the ignition coil from cylinder 6 with an adjacent cylinder (e.g., cylinder 5). Clear the codes and drive the vehicle. If the code changes to P0305, the ignition coil is bad.
5. If the code does not move, inspect the spark plug from cylinder 6. Look for signs of wear, damage, or heavy oil fouling. Replace if necessary.
6. If the coil and plug are good, inspect the wiring and connector for the cylinder 6 ignition coil and fuel injector for any damage or corrosion.
7. If no issues are found and oil consumption is high, proceed with a professional diagnosis, including a cylinder compression and leak-down test, referencing TSBs SSM 54504, SSM 46364, and 19-2243.

Parts You'll Likely Need

• Ignition Coil (OEM #FT4Z-12029-A) — This is a very common failure item for misfire codes. The part number is for the 2.7L and 3.0L engines.
  Trusted brands: Motorcraft, Denso
  OEM price range: $75-$105
  Aftermarket price range: $40-$80
• Ignition Coil (OEM #7T4Z-12029-F) — This is the specific ignition coil for the 3.7L V6 engine.
  Trusted brands: Motorcraft
  OEM price range: $70-$115
  Aftermarket price range: $40-$80
• Spark Plug (OEM #Motorcraft SP-578 (CYFS-12Y-PT)) — Spark plugs are a routine maintenance part and a frequent cause of misfires. This part number is specified for the 2.7L and 3.0L EcoBoost engines. Using the correct iridium plug and gap is critical for turbo engine performance.
  Trusted brands: Motorcraft, NGK
  OEM price range: $10-$25
  Aftermarket price range: $8-$18

Related Codes That Often Appear With This One

• P0300 — If the condition causing the misfire is not isolated to one cylinder (e.g., low fuel pressure or a large vacuum leak), a P0300 Random Misfire code may appear alongside P0306. It is also listed in the TSBs for the major engine fault.
• P0316 — This code indicates a misfire was detected within the first 1,000 engine revolutions at startup. It often appears with specific cylinder misfire codes and is explicitly mentioned in the TSBs related to the engine failure issue. [8, TSB SSM 54504, TSB SSM 46364]
• P0524 — According to TSBs, this code for 'Engine Oil Pressure Too Low' can accompany a P0306 misfire and points towards a probable long block engine issue, likely due to oil starvation from excessive consumption. [8, 13, TSB SSM 54504, TSB SSM 46364]
• P06DD — Similar to P0524, this code for 'Engine Oil Pressure Control Circuit Stuck Off' is mentioned in TSBs as a key indicator of a serious engine problem requiring long block replacement when seen with a misfire. [8, 13, TSB SSM 54504, TSB SSM 46364]

Technical Service Bulletins (TSBs) & Recalls

• SSM 54504: Addresses illuminated MIL with DTCs P0300-P0306 and excessive oil consumption.
• SSM 46364: Links DTCs P0300-P0306 with oil consumption and points to cylinder heads or the long block as the cause.
• TSB 19-2243: Supersedes earlier TSBs for 2.7L/3.0L engines, identifying faulty valve guides as the cause for oil consumption and misfires, and calling for cylinder head replacement.

Platform-Specific Known Issues

• Technical Service Bulletin SSM 54504 notes that 2017 models may exhibit a P0306 code along with excessive oil consumption (1 quart in less than 3,000 miles), pointing to a potential internal engine issue. [TSB SSM 54504]
• Technical Service Bulletin SSM 46364 explicitly states that for a P0306 code with oil consumption, the cylinder heads should be suspected. If codes P0524 or P06DD are also present, the long block is the likely cause. [TSB SSM 46364]
• TSB 19-2243 (superseding earlier versions) provides the most detail for the 2.7L/3.0L engines, identifying the cause as faulty valve guides and outlining the cylinder head replacement procedure for vehicles built between April 1, 2016, and January 1, 2017.

Mechanic-Grade Diagnostic Values

• Ignition Coil Secondary Resistance (2.7L/3.0L) — expected: 7.3 kΩ ±10% (6.6 kΩ - 7.9 kΩ). Failure: A reading of open circuit (OL) or a value significantly outside the expected range.
• Ignition Coil Primary Resistance (2.7L/3.0L) — expected: 0.58 Ω ±10% (0.52 Ω - 0.64 Ω). Failure: A reading significantly outside this narrow range.
• Mode $06 Misfire Counts — expected: Zero or very low counts for each cylinder over the last 10 driving cycles.. Failure: A high number of misfire counts logged for cylinder 6, even if a P0306 code is not yet present.

Hidden / Shadow Codes Worth Checking

• Mode $06, Test ID $A2-$A7: This is not a DTC, but a diagnostic monitor within the PCM. Test IDs $A2 through $A7 correspond to misfire counts for cylinders 1 through 6. A technician can view these raw counts with an advanced scan tool to see which cylinder is misfiring before a code is set. (see via An advanced OBD-II scanner or diagnostic software (like FORScan) that can access Mode $06 test results.)

Scan Tool Commands That Help

• Ford IDS (or equivalent advanced scanner like Snap-on): Power Balance Test — This graphical test shows the power contribution of each cylinder in real-time. A significant drop or erratic pattern for cylinder 6 confirms the misfire location and can help determine if it occurs at idle, under load, or consistently.
• Ford IDS (or equivalent advanced scanner): Misfire Monitor Neutral Profile Correction — This procedure MUST be performed after major engine repairs (like cylinder head or long block replacement), PCM replacement, or crankshaft position sensor replacement. Failure to relearn the crankshaft position profile can cause false misfire codes (P0300, P030x) to be set.

Wiring & Ground Locations

• Cylinder 6 Ignition Coil Connector — On the 2.7L/3.0L V6, cylinder 6 is on the front bank (radiator side), driver's side. The connector plugs directly into the ignition coil mounted on the valve cover.. This connector and its wiring are the final link for the spark command from the PCM. Technicians test for battery voltage, ground, and the command signal from the PCM at this connector's pins to rule out a wiring or PCM driver issue.
• Engine Ground Points — Key engine grounds are typically located on the cylinder heads, engine block, and from the block to the chassis. A comprehensive wiring diagram is needed for exact locations.. A poor or corroded engine ground can cause a weak spark across all cylinders, but can sometimes manifest as an intermittent misfire on a single cylinder due to electrical noise or resistance issues.

Real Owner Repair Stories

• Ford F150 Forum (2016 Ford F-150 2.7L EcoBoost (engine shared with Continental)) — Rough running, check engine light.
  ❌ Tried (didn't work) The dealership initially diagnosed and replaced the ignition coil and spark plug for the misfiring cylinder (#4 in this case).
  ✅ What actually fixed it After replacing the coil and plug, the misfire persisted. Further diagnosis revealed a loss of compression in that cylinder. The technician then needed to pull the valve cover to investigate a potentially stuck valve, acknowledging the possibility of a more serious internal issue despite initially dismissing the owner's mention of the related TSB.

OEM Part Supersession History

• Unknown → FT4Z-12029-A — Standard part lifecycle and potential design improvements.
  Heads up: FT4Z-12029-A is the specified coil for the 2.7L and 3.0L engines in the 2017 Continental. Using other coils may result in improper fitment or electrical incompatibility.

Model Year Variations Within This Range

• 2017 models with 2.7L/3.0L engines built between 01-Apr-2016 and 01-Jan-2017: These specific models are subject to TSBs 19-2243 and SSM 46364, which identify a manufacturing defect in the cylinder head valve guides. Vehicles built outside this window are not expected to have this specific systemic issue, making a P0306 on those vehicles more likely to be a standard ignition or fuel problem.