Mercedes-AMG Coolant temperature sensor replacement

The cost of coolant temperature sensor replacement on a Mercedes-AMG varies by model, engine size and parts quality. Use RepairFair's free estimator to get an accurate price for your specific car.

Each Mercedes-AMG model sits in a different vehicle segment (compact, mid-size, SUV) and has a different engine configuration. Larger, more complex or more premium vehicles require more expensive parts and sometimes more labour time. Select your specific model for an accurate estimate.

Coolant temperature sensor replacement on a Mercedes-AMG typically takes 0.8–2.5 hours of labour. In practice, most garages will complete the job within a half or full working day depending on their schedule.

A coolant flush involves draining the system, flushing it clean and refilling with the correct coolant type and concentration. Coolant itself costs $20–$50 for most vehicles; the job should take 30–60 minutes. Total cost of $80–$160 is typical. Be sceptical of a full machine flush being recommended on a car with clean, recent coolant — a simple drain-and-fill is often sufficient. More importantly, confirm the correct coolant type is being used for your Mercedes-AMG: mixing OAT, HOAT and IAT coolants causes corrosion and silting that can damage the water pump and radiator.

An independent is the right choice for most Mercedes-AMG vehicles. The critical thing is using the correct coolant type — your Mercedes-AMG owner's manual specifies the standard (OAT, HOAT, G11, G12, G13 etc). Any independent can source the correct coolant. Mixing coolant types causes corrosion regardless of who does the job, so confirm the garage knows the specification for your specific Mercedes-AMG engine. Dealer pricing for a coolant flush is typically 50–80% higher for the same outcome.

Brand matters less than type. Mercedes-AMG (like all manufacturers) specifies a coolant standard, not a brand — but using the wrong type causes real damage. Mixing OAT (orange/red, extended-life) with IAT (green, conventional) or HOAT creates a gel-like sludge that blocks small passages in the heater core and water pump. Always use the type specified in your owner's manual or stamped on the coolant reservoir cap. Quality brands including Prestone, PEAK, Zerex and Febi all produce coolants certified to manufacturer standards — check the label matches the requirement for your Mercedes-AMG.

A top-up adds a small amount of pre-mixed coolant to bring the reservoir to the correct level — appropriate when the level has dropped slightly, usually from minor evaporation. A flush replaces the entire coolant volume, restoring the corrosion inhibitors and freeze protection that degrade over time. Topping up old, degraded coolant with fresh coolant dilutes it slightly but does not restore full inhibitor protection. A proper flush is required every 2–5 years depending on the coolant type, regardless of how many top-ups have been done in between.

Fluid changes are manageable for a home mechanic with basic tools and care taken over correct disposal of old fluid. A garage will typically inspect related components at the same time, which adds value to a professional service over a DIY fluid swap.