In this video, you will see the complete process of locating and replacing both Knock Sensor 1 (KS1) and Knock Sensor 2 (KS2) on a Ford Fusion equipped with the 2.0L EcoBoost turbo engine. If your engine lacks power under heavy acceleration, suffers from poor fuel economy, or triggers a check engine light for a knock sensor circuit malfunction, this visual guide shows you exactly where to look on the engine block to find both sensors and how to swap them out.
How this video helps you: The 2.0L EcoBoost engine utilizes two separate knock sensors to monitor internal engine vibrations and detect destructive engine knock (pre-ignition/pinging). Both sensors are bolted directly into the front face of the engine block underneath the intake manifold plenum assembly. Knock Sensor 1 is positioned on the passenger side (Cylinder 1/2 area), while Knock Sensor 2 sits closer to the driver’s side (Cylinder 3/4 area). Because they are completely buried beneath the massive plastic intake manifold, fuel injection wiring looms, and turbocharger charge pipes, they are 100% hidden from view. This video points out their exact positions and demonstrates how to clear away the necessary top-side plumbing and components to gain access to their mounting bolts.
⚠️ CRITICAL TORQUE SAFETY NOTE: Knock sensors are highly sensitive piezoelectric crystals that function like tiny microphones tuned to specific engine frequencies. You must use a torque wrench to tighten the mounting bolts to the exact factory specification of 15 ft-lbs (20 Nm). Under-tightening will make the sensor too loose to pick up engine vibrations, while over-tightening can crush the internal crystal housing, permanently destroying the sensor and causing immediate, un-clearable fault codes upon startup.
Common symptoms of a bad Knock Sensor: The knock sensors act as an ignition safety net. When they fail or send erratic signals, the powertrain control module (PCM) safely retards ignition timing to protect the pistons, leading to these classic issues:
- Check Engine Light & Knock Sensor Fault Codes: A circuit failure, low voltage output, or out-of-range frequency reading will instantly trip the engine light, storing diagnostic trouble codes like P0325 / P0327 (Knock Sensor 1 Circuit) or P0330 / P0332 (Knock Sensor 2 Circuit).
- Severe Sluggishness & Loss of Power Under Load: When the PCM loses confidence in its knock sensors, it drops into a protective ignition timing strategy. You will notice a major drop in acceleration and engine responsiveness, especially when trying to merge on highways or drive up hills under boost.
- Pinging or Metallic Clicking Sounds: If a failed sensor fails to alert the computer that the engine is knocking, you may physically hear a light, rapid metallic “pinging” or rattling noise (like marbles shaking in a tin can) under heavy throttle when using low-octane fuel.
- Increased Fuel Consumption: Because the computer runs a conservative, retarded timing map to prevent potential engine damage, the engine operates far less efficiently, causing your fuel economy to drop noticeably.
Watch the video to see the exact locations on the engine block and replace your knock sensors confidently!