A Guide to the Engine Coolant Temperature Sensor for the 2012-2018 BMW M6
Understanding the signs of a failing coolant sensor and how to choose the right replacement for your S63 engine.
- Verify the sensor's location on your M6 (water pump or cylinder head) before purchasing a new part.
- A faulty sensor can cause poor fuel economy, rough running, and lead to overheating.
- Choose a quality aftermarket brand like Delphi, NGK/NTK, or Standard Motor Products for best results.
- After replacement, you must top off the coolant and properly bleed the system to avoid air pockets.
Is Your M6's Coolant Temp Sensor Failing?
A bad Engine Coolant Temperature (ECT) sensor can cause more than just a faulty reading on your dash. Because the ECU relies on its data for engine management, a failure can lead to noticeable performance issues. Your M6 might run rough, especially when cold, get worse gas mileage, or have black smoke from the exhaust. The most obvious sign is the check engine light coming on, often with specific error codes.
Choosing the Right Aftermarket Sensor
When replacing the ECT sensor on your M6, you have options outside of the expensive dealership part. However, not all aftermarket brands are created equal. For a critical component like this, quality matters.
Tier 1: OEM Quality & Reputation
These brands are often original equipment (OE) suppliers to BMW and other German automakers or have a long-standing reputation for producing parts that meet or exceed OE standards. They are an excellent choice for owners who want maximum reliability and peace of mind.
- Delphi: With over 100 years of OE experience, Delphi parts are engineered to high standards and are a trusted name in automotive electronics.
- NGK/NTK: While famous for spark plugs, NTK (the sensor division of NGK) is a major player in the sensor market, known for high-quality, reliable products.
- Standard Motor Products (SMP): A well-regarded brand that emphasizes quality control and testing to ensure their sensors provide accurate readings and have a long service life.
- Beck Arnley: This brand specializes in parts for foreign nameplate vehicles, focusing on matching the original part's form, fit, and function.
Tier 2: Value-Focused Options
These brands provide a more budget-friendly alternative. They are a viable option for repairs on a tighter budget, though they may not always have the same reputation for longevity as Tier 1 brands.
- URO Parts: Known for being an affordable alternative to genuine parts, URO is a common choice for DIY repairs.
- Vemo: Another brand that offers a wide range of aftermarket parts for European vehicles, often at a competitive price point.
- Four Seasons / Walker Products / Global Parts: These brands offer a broad catalog of cooling and engine management parts that provide a functional, cost-effective replacement.
Important: Check Location Before You Buy!
The location of the primary ECT sensor on the 2012-2018 M6 can vary. Some parts listings indicate the sensor is located on the water pump for 2012-2016 models, while for 2018 models it may be on the cylinder head. Always verify the location on your specific vehicle before ordering to ensure you get the correct part.
Cost of Replacing the Sensor
The cost to replace the ECT sensor is reasonable, especially if you do the work yourself. Below is an estimated breakdown.
| Item | Estimated Cost |
|---|---|
| New OEM Sensor | $48 - $66 |
| New Aftermarket Sensor | $19 - $69 |
| Shop Labor | $75 - $150 |
| Total (Shop Repair) | $94 - $219 |
Frequently Asked Questions
Can I replace the M6 coolant temperature sensor myself?
Yes, this is a DIY-friendly job for someone with basic mechanical skills. The sensor is usually held in by a clip or threaded in. The main challenge is accessing it in the M6's crowded engine bay and working quickly to minimize coolant loss. Always work on a cold engine and wear gloves.
Do I need to drain the coolant to replace the sensor?
While a full drain is the 'correct' way, you can often replace the sensor without draining the entire system. Have the new sensor ready to swap in quickly to minimize spillage. Be prepared to top off the coolant afterward and, most importantly, properly bleed the system to remove any air pockets, which can cause overheating.
Are there any recalls for the M6 coolant temperature sensor?
As of now, there are no specific NHTSA recalls for the engine coolant temperature sensor on the 2012-2018 BMW M6. Always check for the latest recall information using your vehicle's VIN on the NHTSA website.
My code is P0128. Is it the sensor or the thermostat?
The P0128 code means the engine isn't warming up as fast as the ECU expects. This is most often caused by a thermostat that is stuck open. However, a faulty ECT sensor providing incorrect readings can also trigger this code. If you have a P0128 code, it's common to inspect or replace the thermostat first, but the sensor is also a potential cause.
Pro Tip: Check for Leaks
The sensor is sealed with an O-ring or washer. When replacing the sensor, make sure the old seal comes out with it and the new one is properly seated. After the repair, run the engine and check for any coolant leaks around the new sensor.
Technical Specifications
OEM Part Numbers: 13-62-7-580-635
The sensor is a thermistor with a 2-pin connector that changes electrical resistance based on coolant temperature. It is sealed with an O-ring and typically requires a deep socket or wrench for removal.
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.
- BMW M6: