In this video, I show you the exact location and the complete step-by-step process to replace the Engine Coolant Temperature (ECT) sensor on a 2006-2013 Chevrolet Impala equipped with the 3.5L V6 engine.
Knowing exactly where this sensor is threaded into the engine block and how to swap it out will save you time, keep your workspace clean, and prevent you from damaging the delicate plastic electrical connector during this DIY repair.
Common Symptoms of a Bad Engine Coolant Temperature (ECT) Sensor:
- The check engine light comes on, frequently flagging performance or circuit codes like P0117, P0118, or P0128
- The temperature gauge on the dashboard acts erratically, drops to zero, or reads completely maxed out
- The radiator cooling fans run constantly on high speed as a safety measure, or refuse to turn on at all
- A sudden drop in fuel economy or a rich-running engine condition (heavy raw fuel smell from the exhaust)
- Hard starting issues when the engine is cold, or engine stumbling and rough idling at stoplights
Safety First
Always prioritize safety when opening any part of the engine cooling system. Never attempt to remove the ECT sensor or the coolant pressure cap while the engine is hot. The system operates under high pressure, and escaping boiling liquid or steam can cause severe, painful burns. Ensure the vehicle is safely parked on a flat, level surface, the engine is completely cold, and the keys are out of the ignition. Consider disconnecting the negative battery terminal to prevent electrical shorts. Protect your eyes and skin by wearing safety glasses and fluid-resistant work gloves, and use a clean drain pan under the engine to catch the escaping fluid.
Need Help? Ask an Expert
I am an experienced mechanic, and I am here to help you guide your vehicle projects to a successful finish. If you hit a snag trying to disconnect the stubborn plastic locking tab on the harness, aren’t sure how to properly bleed the air pockets out of the cooling system after refilling, or are dealing with a tricky breakdown, leave a message in the comments below. Let me know what you are running into, and I will help you solve your car’s problem!