Cylinder 3 Misfire Detected

Cylinder 3 misfire on the Pentastar V6. Perform a coil swap test -- move the coil from cylinder 3 to another cylinder. If the misfire follows, replace the coil. If it stays on cylinder 3, check the spark plug and fuel injector. On high-mileage Pentastar engines, rocker arm failures on cylinder 3 are known -- listen for a ticking noise.

Cylinder 3 misfire on EcoBoost. Swap the ignition coil from cylinder 3 to verify. If coil is good, check for carbon buildup on the intake valve using a borescope -- direct injection engines are prone to carbon fouling. Also check the spark plug gap -- Ford spec is 0.028 inch for EcoBoost. Use Motorcraft plugs only. Confirm the exact part for your year and engine with a retailer's fitment lookup or your VIN before ordering - these applications split by engine and build date.

Cylinder 3 on the 5.3L is NOT an AFM cylinder, so lifter failure is less likely. Perform a coil swap test first (ACDelco). If the coil and plug are good, check the fuel injector balance rate with a scan tool. Also check for a vacuum leak at the intake manifold gasket near cylinder 3. Compression test if all else checks out. Confirm the exact part for your year and engine with a retailer's fitment lookup or your VIN before ordering - these applications split by engine and build date.

Cylinder 3 misfire on the VQ35DE V6. Check the ignition coil (Hitachi) and spark plug first. Cylinder 3 is the rear bank center cylinder. If coil and plug are good, check for a clogged fuel injector. Seafoam fuel system cleaner can help if the injector is partially clogged. A compression test will rule out internal engine damage. Confirm the exact part for your year and engine with a retailer's fitment lookup or your VIN before ordering - these applications split by engine and build date.