Cooling System · important priority
Coolant Temperature Sensor Replacement Cost & Pricing
Replace the engine coolant temperature sensor (ECT) that feeds coolant temperature data to the ECM. A faulty sensor causes poor fuel economy, rich running, a cold-running gauge, failed emissions, or an illuminated check engine light (P0115–P0119).
Typical Coolant Temperature Sensor Replacement cost
$80–$260, with an average estimate of $140 before vehicle-specific adjustments.
What to expect
Difficulty: easy. Typical labor time: 0.5–1.5 hours.
Mechanic's tip
This is one of the cheaper sensor replacements on any engine — the part is usually $15–50. Always drain some coolant before removal to avoid burning yourself or making a mess. An engine that runs great when warm but acts rich (black smoke, poor mpg) when cold is a classic failing ECT symptom. Confirm with live data on a scan tool — the ECT reading should match the coolant temperature gauge on the dash.