Where is the coolant temperature sensor on the Aveo?

The coolant temperature sensor on most Aveo models is mounted in the engine block at the thermostat housing on the passenger side, near the top radiator hose. Some early Kalos/Aveo variants place the sensor in the intake manifold or at the water outlet housing, so exact placement can vary by year and engine.

In this article, we outline the typical locations you should check first, explain how to identify the sensor on your specific engine, and offer practical steps for confirming its position and condition.

Common locations on Aveo engines

Below are the spots most Aveo owners should inspect first. The following list reflects the two most common configurations found across generations of the Aveo/Kalos line.

• Thermostat housing area — usually on the engine block, on the passenger side, where the upper radiator hose attaches. This is the most typical site for the coolant temperature sensor on many Aveo engines.


• Intake-related housing or water outlet area — in some early Kalos/Aveo variants, the sensor may be mounted in the intake manifold or near the water outlet housing, accessible from the top of the engine bay.

Locations can vary by model year and engine code. If your vehicle isn’t found at the two common spots above, consult the factory service manual or a VIN-specific diagrams for your exact engine.

How to identify and verify the coolant temperature sensor on your Aveo

Use these steps to locate and confirm the sensor’s position on your specific Aveo model. The steps are designed to help you avoid confusing the coolant sensor with other temperature sensors in the system.

1. Park on a level surface and ensure the engine is cool before starting any inspection.


2. Open the hood and locate the thermostat housing on the engine block, typically near the top radiator hose on the passenger side.


3. Look for a small brass or steel sensor threaded into a hole in the housing, with a two-pin electrical connector plugged into it.


4. If you don’t find it there, trace the heater hose connections and inspect nearby areas on the cylinder head or the intake manifold for a sensor with a two-wire connector.


5. Carefully disconnect the sensor’s electrical connector to inspect the harness for corrosion, wear, or loose pins. Reconnect securely when finished.


6. If you have access to a scan tool, read the engine coolant temperature data and compare it to the actual coolant temperature. If the readings are inconsistent or the sensor reads far from real temperature, the sensor may be faulty.


7. If you need to replace it, ensure you use the correct GM/Delphi (or OE) part for your engine code, and apply thread sealant if required by your specific installation instructions.

In practice, starting your search at the thermostat housing is a reliable first step, and expanding outward to the intake manifold or water outlet area covers the remaining common placements.

Additional considerations and tips

Model-year and engine-code variations

The Aveo/Kalos lineup includes multiple engines across years, and sensor placement can shift with redesigns or regional specifications. Always confirm the exact engine code (for example, 1.4L or 1.6L variants) and reference the corresponding service manual or a VIN-based diagram for precise placement.

Replacement and maintenance reminders

When replacing the sensor, ensure you use the correct sensor type for your engine and verify the electrical connector matches. After replacement, clear any trouble codes with a scan tool and monitor the coolant temperature reading to confirm accurate operation.

Summary

The coolant temperature sensor on the Aveo is most commonly found at the thermostat housing on the passenger side of the engine block, near the upper radiator hose. Some early Kalos/Aveo models place the sensor in the intake manifold or near the water outlet housing. If you can’t locate it in these spots, consult the vehicle’s service manual or a VIN-specific diagram for your exact engine configuration. Verifying with a scan tool or manual test can help confirm sensor function and ensure reliable engine management.

Why is my Chevy Aveo overheating?

Chevy Aveo overheating is often caused by a failing thermostat, coolant leaks, or a malfunctioning radiator fan. Other potential culprits include a clogged radiator, a faulty water pump, or even a blown head gasket. To diagnose the problem, check for visible leaks, ensure the cooling fans are working, and inspect the thermostat, radiator, and hoses. 
Common causes 
This video explains how to diagnose a Chevy Aveo overheating issue: 49sPhillip BaileyYouTube · Aug 6, 2020

• Thermostat issues: A thermostat that is stuck closed or not opening fully can prevent coolant from circulating, leading to overheating. 
• Coolant leaks: Leaks from the radiator, hoses, water pump, or thermostat housing can cause coolant loss, which lowers the system's ability to cool the engine. A faulty radiator cap can also cause leaks. 
• Faulty radiator fan: The cooling fan may not be engaging properly, especially at low speeds or when the A/C is on, leading to overheating. 
• Clogged radiator: Over time, sediment or corrosion can build up inside the radiator, restricting coolant flow. 
• Blown head gasket: In severe cases, a blown head gasket can allow exhaust gases into the cooling system, causing overheating, pressure buildup, and white smoke. 

How to diagnose

• Check for leaks: Look for puddles under the vehicle or signs of coolant on hoses, the radiator, or the engine. 
• Inspect the radiator fan: Verify that the fan turns on when the engine reaches operating temperature or when the A/C is running. 
• Check the thermostat: Feel the upper and lower radiator hoses after the engine warms up. If the upper hose is hot but the lower hose is cool, the thermostat is likely stuck closed. 
• Examine the coolant: Look for signs of contamination, like a milky or oily residue, which can indicate a head gasket failure. 
• Perform a pressure test: Have a mechanic perform a pressure test on the cooling system to pinpoint any leaks or use a block tester to check for exhaust gases. 
• Check the radiator cap: A faulty cap can cause pressure loss. A mechanic can test its ability to hold pressure. 

You can watch this video to learn how to replace a radiator cap on a Chevy Aveo: 55sNewYorkerInCTYouTube · Dec 17, 2017
Solutions

• Replace the thermostat: If the thermostat is faulty, replacing it is a straightforward solution. 
• Repair leaks: Fix any leaks found in the hoses, radiator, or other components. 
• Flush the cooling system: A coolant flush can help clear out blockages in the radiator and passages. 
• Replace faulty parts: If the water pump, radiator, or fan are failing, they will need to be replaced. 
• Address head gasket issues: If a head gasket is the cause, it will need professional repair. 

Where is the coolant temperature sensor located?

The engine coolant temperature sensor is typically located near the thermostat housing, at the front of the engine where the upper radiator hose connects. It screws into a metal port on the engine block, cylinder head, or water pump housing and can be identified by the electrical connector attached to it. 
This video shows the location of the engine coolant temperature sensor on a specific car model: 55sRed Pill GarageYouTube · Feb 19, 2022
Common locations

• Thermostat housing: This is the most common location, found at the front of the engine where the top radiator hose connects to the engine. 
• Cylinder head: In some cases, the sensor may be screwed directly into a cylinder head. 
• Water pump housing: It can also be located on or near the water pump housing. 
• Coolant crossover pipe: On some engines, like those with a V-shaped cylinder configuration, the sensor might be on a crossover pipe under the intake manifold. 

You can watch this video to see a close-up of the coolant temperature sensor in place: 41srichpin06aYouTube · May 8, 2021
How to find it

• Follow the top radiator hose: The easiest way to find the sensor is to locate the upper radiator hose and follow it to where it enters the engine. The sensor is usually nearby. 
• Look for the electrical connector: The sensor is distinguished by a wire harness connector plugged into it. 
• Check your repair manual: If you're having trouble finding it, consult your vehicle's repair manual for a diagram of your specific engine. 
• Do a quick online image search: Searching for "engine coolant temperature sensor location" along with your car's make and model can provide a specific visual reference. 

What happens when your coolant temperature sensor goes bad?

Symptoms of a bad coolant temperature sensor include an erratic temperature gauge, engine overheating, illuminated check engine light, poor fuel economy, and a rough idle or stalling. Other signs can be the cooling fan not working correctly, black smoke from the exhaust, and difficulty starting the engine. 
Performance and operational symptoms

• Engine overheating: The most critical symptom, as the sensor failing can prevent the engine from properly engaging the cooling fan. 
• Erratic temperature gauge: The needle may show a constantly high, low, or fluctuating temperature. 
• Rough idle and stalling: The engine's computer uses the sensor's data to calculate the right air-fuel mixture. An incorrect reading can cause the engine to run poorly, idle roughly, or stall, especially when cold. 
• Poor fuel economy: The car may use more fuel than it should because the engine computer is getting incorrect information about engine temperature and is adjusting the air-fuel mixture incorrectly. 
• Difficulty starting: The engine may be hard to start, especially when warm, due to the wrong amount of fuel being injected. 

Exhaust and emissions symptoms

• Black smoke from exhaust: This indicates the engine is running too rich (too much fuel), which can be caused by the sensor sending a faulty "cold" signal. 
• Increased emissions: The incorrect air-fuel mixture can lead to higher emissions, potentially causing your car to fail an emissions test. 

Other warning signs

• Check engine light: The engine control unit (ECU) will trigger the light if it detects a problem with the sensor's data. 
• Cooling fan malfunction: The radiator fan may not turn on when the engine gets hot, or it may run constantly. 
• Poor engine performance: You may experience reduced power, misfires, or engine pinging. 

Where is the coolant temperature sensor on a 2004 Chevy Aveo?

The coolant temperature sensor on a 2004 Chevy Aveo is located near the thermostat housing on the engine block. Symptoms of a faulty sensor include erratic temperature gauge readings or poor engine performance.