How much does a thermostat replacement cost?

A thermostat replacement typically costs $150-$400 including parts and labor. It is one of the more affordable cooling system repairs and can resolve many temperature-related codes.

Why does my car keep overheating?

Common causes include a stuck thermostat, low coolant from leaks, a failed water pump, a clogged radiator, or malfunctioning cooling fans. A proper diagnosis is needed to identify the specific cause.

P0494

Fan Speed Low

Moderatecooling

Overview

The P0494 diagnostic trouble code indicates a fan speed low condition. This code relates to the engine cooling system, which maintains proper operating temperature for the engine. Cooling system problems can lead to overheating and serious engine damage if not addressed in a timely manner.

Symptoms

Check Engine Light (MIL) illuminated
Coolant leak
Sweet smell from engine bay (coolant leak)
Poor heater performance

Common Causes

Malfunctioning cooling fan or relay
Faulty engine coolant temperature sensor
Failed water pump
Damaged radiator hoses

Diagnosis Steps

1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
2Check coolant level and inspect for visible leaks
3Test the thermostat by monitoring coolant temperature during warm-up
4Inspect the coolant temperature sensor and its wiring
5Test the cooling fan operation by running the AC or using a scan tool

Estimated Repair Cost

$100 — $800

Cost varies by vehicle, location, and repair shop. Includes parts and labor.

Commonly Affected Vehicles

BMW 3 SeriesAudi Q5Ford TaurusJeep Grand Cherokee

Related Codes

P0480 P0217 P0115

More Cooling Codes

P0115Engine Coolant Temperature Circuit Malfunction

Moderate

P0116Engine Coolant Temperature Circuit Range/Performance

Moderate

P0117Engine Coolant Temperature Circuit Low Input

Moderate

P0118Engine Coolant Temperature Circuit High Input

Moderate

P0119Engine Coolant Temperature Circuit Intermittent

Moderate

P0125Insufficient Coolant Temperature for Closed Loop Fuel Control

Moderate

Frequently Asked Questions

If your engine is overheating, stop driving immediately to prevent catastrophic engine damage. If the code is related to a sensor or thermostat and the temperature is stable, drive cautiously to a repair shop.