Comprehensive Diagnostic Evaluation of an Intermittent Misfire Condition
Vehicle Information
Vehicle: 2018 Ford Edge AWD
Engine: 3.5L V6 DOHC Ti-VCT
VIN: 2FMPK4K83JBC44501
Date of Final Evaluation: June 19, 2026
Engine Identification Number: T1ET0780032
Remanufactured Engine Supplier: Non-OE Remanufacturer
Mileage History
Mileage at Engine Installation: 147,490 Miles
Mileage at Initial Diagnostic Evaluation: 152,746 Miles
Mileage at Final Diagnostic Evaluation: 153,148 Miles
Mileage at Completion of Testing: 153,170 Miles
1. Initial Complaint
A remanufactured engine was installed in the vehicle at 147,490 miles.
Following installation, an intermittent engine misfire was observed.
Initial scan tool monitoring identified misfire activity primarily affecting Cylinder Number 2.
The engine otherwise operated normally and did not exhibit:
- Catastrophic mechanical noise
- Oil consumption
- Coolant consumption
- Overheating
- Excessive smoke
- Severe drivability concerns
After consultation with the remanufacturer, the customer was advised to continue operating the vehicle during the engine break-in period while the condition was monitored.
2. Follow-Up Evaluation
At 152,746 miles, the customer returned for further evaluation.
The customer reported that the engine had improved significantly during the break-in period. However, a slight intermittent misfire remained noticeable under light load in higher gears.
Diagnostic procedures performed included:
- Replacement of Cylinder Number 2 spark plug
- Ignition coil interchange testing
- Scan tool monitoring
- Misfire counter analysis
The misfire remained associated with Cylinder Number 2.
The engine continued to run smoothly otherwise.
No abnormal mechanical noise was present.
No evidence of catastrophic engine failure was observed.
The remanufacturer was contacted for additional guidance.
The remanufacturer requested the following tests if the condition persisted:
- Compression test
- Cylinder leak-down test
- Borescope inspection
The vehicle was returned to the customer for additional break-in mileage.
3. Injector Replacement and Continued Evaluation
The vehicle was returned for further evaluation.
All fuel injectors were replaced as a precautionary measure.
Following injector replacement, the vehicle was returned to the customer for additional operation and break-in mileage.
The remanufacturer was again consulted.
The remanufacturer requested that the following procedures be completed if the condition remained present:
- Compression testing
- Leak-down testing
- Borescope inspection
4. Final Diagnostic Evaluation
At 153,148 miles, the vehicle returned for comprehensive diagnostic testing.
The customer reported continued improvement in engine operation.
At the time of inspection:
- Engine oil level was full
- No oil consumption had been reported
- No coolant loss had been reported
- No overheating concerns had been reported
- No abnormal mechanical engine noise was present
- No evidence of catastrophic engine failure was observed
The only remaining concern was intermittent engine misfire activity.
5. Diagnostic Equipment Utilized
The following diagnostic equipment was used during the evaluation.
Scan Tool
Snap-on Solus Edge
Compression Tester
Mac Tools CT3015B Compression Tester
Leak-Down Tester
OTC Model 5609 Cylinder Leakage Tester
Borescope
Cen-Tech Digital Inspection Camera
All diagnostic results contained within this report were obtained using the equipment listed above.
6. Scan Tool Findings
Diagnostic Trouble Codes Present
- P0300 — Random Misfire Detected
- P0302 — Cylinder Number 2 Misfire Detected
- P0306 — Cylinder Number 6 Misfire Detected
Misfire Counter Data
Cylinder Number 2
Current Drive Cycle Misfires: 1,026 Counts
Cylinder Number 6
Current Drive Cycle Misfires: 1,019 Counts
All remaining cylinders showed minimal or insignificant misfire activity.
PCM Fault Monitoring
PCM fault monitoring indicated:
- Injector faults: None detected
- Camshaft position sensor faults: None detected
- Cylinder head temperature faults: None detected
- EVAP venting faults: None detected
No electronic control system faults were identified that would explain the misfire condition.
7. Leak-Down Testing
Leak-down testing was performed with the engine warmed to operating temperature.
Valve covers were removed to permit visual observation of valve train operation.
The cylinders were positioned at Top Dead Center on the compression stroke.
Approximately 75 PSI shop air pressure was applied using the OTC 5609 Cylinder Leakage Tester.
Cylinder Number 2
Supply Pressure: Approximately 75 PSI
Cylinder Retention: Approximately 10–12 PSI
Cylinder Number 4
Supply Pressure: Approximately 75 PSI
Cylinder Retention: Approximately 10–12 PSI
Cylinder Number 6
Supply Pressure: Approximately 75 PSI
Cylinder Retention: Approximately 10–12 PSI
Observations
Leakage appeared primarily through the crankcase area.
No significant intake valve leakage was identified.
No significant exhaust valve leakage was identified.
No cooling system leakage was identified.
All tested cylinders produced similar leak-down results.
No leak-down result identified a defect unique to Cylinder Number 2 or Cylinder Number 6.
8. Compression Testing
Compression testing was performed using a Mac Tools CT3015B Compression Tester.
Testing Conditions
- Engine at operating temperature
- Throttle plate held fully open
- Four compression strokes per cylinder
- Same gauge used for all cylinders tested
Results
Cylinder Number 2: Approximately 120 PSI
Cylinder Number 4: Approximately 128 PSI
Cylinder Number 6: Approximately 135 PSI
Observations
Cylinder Number 2 produced the lowest compression reading of the cylinders tested.
The difference between the highest and lowest cylinder tested was approximately 15 PSI.
No cylinder demonstrated catastrophic compression loss.
Compression values remained within a relatively close operating range.
9. Borescope Inspection
A borescope inspection was performed using a Cen-Tech Digital Inspection Camera.
The cylinders were visually inspected through the spark plug openings.
Findings
- No visible piston damage identified
- No visible cylinder wall damage identified
- No visible valve damage identified
- No evidence of coolant intrusion identified
- No evidence of severe oil contamination identified
Conclusion
The borescope inspection was inconclusive for identifying the source of the misfire condition.
No catastrophic internal engine damage was observed.
10. Spark Plug Inspection
Spark plugs from Cylinders Number 2, 4, and 6 were inspected and photographed.
Findings
- No oil fouling identified
- No coolant contamination identified
- No evidence of detonation identified
- No evidence of overheating identified
- No abnormal deposits identified
Spark plug appearance was generally consistent among the inspected cylinders.
11. Lubrication System Findings
Engine oil level was verified full during inspection.
Findings
- No oil consumption reported by the customer
- No oil-fouled spark plugs identified
- No evidence of excessive oil contamination observed
- No indication of severe oil-control ring failure identified
Engine oil level remained within specification throughout the evaluation period.
12. Scope of Findings
Based upon all diagnostic procedures performed through June 19, 2026, the presence of intermittent engine misfire activity was confirmed.
Misfire activity was observed on both:
- Cylinder Number 2
- Cylinder Number 6
Diagnostic testing did not identify:
- Catastrophic engine failure
- Valve failure
- Head gasket failure
- Piston failure
- Cylinder wall damage
- Coolant intrusion
- Excessive oil consumption
- Injector control faults
- Camshaft position sensor faults
Compression testing identified Cylinder Number 2 as the lowest compression cylinder tested.
However, compression remained within a relatively close range of the comparison cylinders.
Leak-down testing did not identify a defect isolated to Cylinder Number 2 or Cylinder Number 6.
Borescope inspection did not identify visible internal engine damage.
Spark plug inspection did not identify abnormal combustion indicators.
At the completion of diagnostic testing on June 19, 2026, intermittent misfire activity remained present on Cylinder Number 2 and Cylinder Number 6.
Comprehensive diagnostic testing confirmed the condition but did not identify a conclusive mechanical failure responsible for the misfire.
No catastrophic internal engine damage was identified during the evaluation.
Testing did not identify evidence of:
- Valve failure
- Piston failure
- Cylinder wall failure
- Head gasket failure
- Coolant intrusion
- Excessive oil consumption
The diagnostic findings, photographs, scan tool data, compression test results, leak-down test results, borescope inspection results, spark plug inspections, and mileage records should be submitted to the remanufacturer for review and further guidance regarding warranty determination and recommended corrective action.
Date: June 19, 2026
Mileage at Completion: 153,170 Miles
Diagnostic Time Invested: Approximately 4.0 Hours
Diagnostic Equipment
- Snap-on Solus Edge
- OTC 5609 Leak-Down Tester
- Mac Tools CT3015B Compression Tester
- Cen-Tech Digital Borescope