Engine Coolant Temperature Sensor Guide for the 2011-2017 Buick Regal
Is your Buick Regal running rough, getting poor gas mileage, or overheating? A faulty engine coolant temperature sensor could be the culprit.
- Confirm your engine (2.4L or 2.0L Turbo) before ordering, as the sensor location is different for each.
- Symptoms like a maxed-out temperature gauge, disabled A/C, and poor fuel economy strongly point to a failing ECT sensor.
- ACDelco is the OEM brand, ensuring a direct factory replacement, while brands like NTK and Delphi offer reliable quality.
- A P0128 trouble code can be caused by this sensor, not just a bad thermostat.
Is Your Buick Regal's Engine Coolant Temp Sensor Failing?
A bad Engine Coolant Temperature (ECT) sensor can cause a surprising number of problems. Because the sensor's reading affects so many engine functions, a false signal can lead the computer to make poor decisions. Watch for these common signs of failure in your Regal.
🎬 Watch a breakdown of the most common bad sensor symptoms.Key Symptoms of a Bad ECT Sensor:
- Check Engine Light: This is often the first sign. The computer will log a fault code like P0117, P0118, or P0128 when it detects a problem with the sensor's signal.
- Poor Fuel Economy: If the sensor incorrectly tells the computer the engine is always cold, the computer will continuously supply a rich fuel mixture, wasting gas.
- Engine Overheating or Incorrect Gauge Readings: A faulty sensor can fail to trigger the cooling fans when needed, leading to overheating. Conversely, it might send a false hot signal, causing the temperature gauge to max out and an "A/C Off Due to High Engine Temp" message to appear, even when the engine is cold.
- Rough Idle and Poor Performance: With incorrect temperature data, the engine's air-fuel mixture and ignition timing will be off, causing a rough or surging idle and sluggish acceleration.
- Black Smoke from Exhaust: A very rich fuel mixture from a bad sensor signal can result in unburned fuel entering the exhaust, creating black smoke.
Vehicle-Specific Issues: TSBs and Known Problems
While no direct recalls exist for this sensor on the 2011-2017 Regal, General Motors has issued Technical Service Bulletins (TSBs) related to it. One bulletin notes that an incorrect sensor signal can cause the engine computer to close off coolant flow, leading to an overheating condition. Another TSB for a different code suggests inspecting the sensor's electrical connector for a poor connection. Owners have also frequently reported the P0128 code, which can be caused by either a bad thermostat or a faulty ECT sensor.
Choosing the Right Aftermarket Sensor for Your Regal
You don't need to buy from the dealer to get a quality part. For a critical sensor like this, however, quality matters. Aftermarket brands can be grouped into tiers based on their relationship with the original manufacturer (OEM).
Tier 1: OEM and OEM-Equivalent Brands
- ACDelco: As the original equipment manufacturer for General Motors, an ACDelco sensor is the same part your Buick Regal was built with. Choosing ACDelco guarantees a perfect fit, function, and reliable performance.
- Delphi: Delphi is another major OEM supplier for many automakers, including GM. Their parts are engineered to meet or exceed factory specifications and are a trusted alternative to ACDelco.
Tier 2: Quality Aftermarket Brands
These brands are known for producing reliable parts that offer a great balance of performance and value.
- NGK / NTK: A world leader in sensors and ignition components, NTK (a brand of NGK) offers high-quality ECT sensors that are a dependable choice.
- Standard Motor Products (Standard Ignition / True Tech): A long-standing and respected aftermarket manufacturer that produces a wide range of quality sensors.
- Holstein: This brand focuses on sensors and electrical components, offering parts that are designed to be direct OE replacements.
Tier 3: Budget-Friendly Options
Brands like Facet, Four Seasons, Global Parts, Motorad, and Walker Products often provide the most affordable options. While functional, they may not have the same level of validation or longevity as higher-tier brands. They can be a good choice for budget-conscious repairs where top-tier quality is not the primary concern.
Pro Tip: Check Your Engine Before You Buy
The 2011-2017 Buick Regal came with two primary engines: the 2.4L 4-cylinder and the 2.0L Turbo 4-cylinder. The location of the ECT sensor is different for each. On the 2.4L engine, the sensor is located in the thermostat housing. 🎬 See how to replace the sensor on the 2.4L engine. On the 2.0L Turbo, it is found at the left rear (driver's side) of the cylinder head. Always confirm your engine to ensure you are looking for the part in the right place.
Cost of Replacing a Buick Regal ECT Sensor
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket | $15 - $51 |
| New OEM (ACDelco) | $20 - $55 |
| Shop Labor | $75 - $150 |
Cost estimates are for parts and labor and may vary by location and vehicle engine type.
Frequently Asked Questions
Can I replace the ECT sensor myself?
Yes, this is a DIY-friendly job for most home mechanics. The sensor is typically easy to access on both the 2.4L and 2.0L engines. You will need basic hand tools, including a deep socket. Be prepared for some coolant to spill when you remove the old sensor; have the new one ready to install quickly to minimize loss. Always perform this repair on a cold engine.
Where is the ECT sensor located on my 2011-2017 Regal?
It depends on your engine. For the 2.4L engine, the sensor is in the thermostat housing. For the 2.0L Turbo engine, it is at the left rear of the cylinder head, near the driver's side.
My car has a P0128 code. Is it the sensor or the thermostat?
The P0128 code means the engine isn't reaching operating temperature as quickly as expected. This is most often caused by a thermostat that is stuck open, but it can also be caused by a faulty ECT sensor that is sending inaccurate readings. If you don't have other sensor-related symptoms (like an erratic gauge), the thermostat is the more likely culprit. However, given the low cost of the sensor, some mechanics replace both at the same time.
What happens if I don't replace a bad ECT sensor?
Ignoring a bad sensor is not recommended. You will experience poor fuel economy and rough performance. More critically, you risk engine damage from overheating if the sensor fails to activate the cooling fans, or you could damage your catalytic converter from running a rich fuel mixture for too long.
Helpful Videos
Technical Specifications
OEM Part Numbers: 12608814 12636534 12650595
The sensor is a two-terminal thermistor that changes resistance based on coolant temperature. It typically has a threaded body (M12 x 1.5 thread is common) and a plastic electrical connector.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Buick Regal:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is Your Buick Regal's Engine Coolant Temp Sensor Failing?
- Key Symptoms of a Bad ECT Sensor:
- Vehicle-Specific Issues: TSBs and Known Problems
- Choosing the Right Aftermarket Sensor for Your Regal
- Tier 1: OEM and OEM-Equivalent Brands
- Tier 2: Quality Aftermarket Brands
- Tier 3: Budget-Friendly Options
- Pro Tip: Check Your Engine Before You Buy
- Cost of Replacing a Buick Regal ECT Sensor
- Frequently Asked Questions
- 🎟️ Get 5% Off