BMW 550i (2006-2016) Engine Coolant Temperature Sensor: A Complete Guide
Diagnosing and replacing the right coolant temperature sensor on your E60 or F10 550i to solve overheating, rough running, and fan issues.
- The 2006-2010 E60 550i has at least two different coolant sensors; identify the correct one before buying.
- A constantly running cooling fan is a classic symptom of a failed radiator outlet temperature sensor.
- For critical sensors, choosing an OEM-supplier brand like Delphi or Vemo is a wise investment for reliability.
- Replacing the sensor in the lower radiator hose is a simple DIY job that can be done in under 30 minutes.
Is Your 550i's Coolant Sensor Failing?
A bad coolant temperature sensor can cause confusing symptoms that might seem unrelated. Because the sensor's signal is so important, the engine computer (DME) will often go into a "fail-safe" mode when it gets a bad reading. This can make it seem like you have a much bigger problem.
Common Symptoms of Failure:
- Check Engine Light: This is the most common sign. You will likely see fault codes such as P0117 (Circuit Low) or P0118 (Circuit High).
- Cooling Fan Runs Constantly: The fan may switch to full speed immediately after starting the car and never turn off. This happens because the DME receives a signal indicating an overheat condition (even if the engine is cold) and runs the fan at maximum as a precaution.
- Poor Engine Performance: You might experience rough idling, hesitation, or reduced power, especially when the engine is cold. This can happen if the sensor incorrectly tells the DME the engine is already warm, leading to the wrong fuel mixture.
- Worse Fuel Economy: If the sensor is stuck reading cold, the DME will continuously provide a rich fuel mixture, wasting gas.
- Incorrect Temperature Gauge Reading: The gauge on your dashboard may behave erratically, shoot to hot instantly, or not move at all.
A Note on 550i Generations
The 2006-2016 model years span two different 550i versions, and they have different sensor setups.
- E60 550i (2006-2010): These cars with the N62 V8 engine have two main coolant temperature sensors. One is located on the engine itself (often near the thermostat), and a second is located in the lower radiator hose on the passenger side. The sensor in the hose primarily controls the electric cooling fan.
- F10 550i (2011-2016): These cars with the N63 twin-turbo V8 also have multiple sensors. The most commonly replaced one is located on the radiator outlet. Other sensors may be integrated into the thermostat housing and are not sold separately.
Choosing the Right Aftermarket Sensor
For sensitive electronics on a BMW, brand quality matters. While you can save money with a budget part, a premature failure will have you doing the job all over again. We've grouped the available brands into tiers based on their reputation among BMW owners and mechanics.
Tier 1: OEM Supplier Quality
These brands are known to manufacture parts for BMW directly. Choosing one of these is the safest bet outside of buying a part from the dealer.
- Delphi: With over 100 years of OE experience, Delphi is a top choice for sensors that deliver accurate readings and long life.
- Vemo: Often an Original Equipment Manufacturer (OEM) for various German brands, Vemo is a trusted name for quality components.
- NGK (NTK): While famous for spark plugs, their NTK sensor line is also highly regarded for its quality.
Tier 2: Reputable Aftermarket
These brands have a long history of producing reliable aftermarket parts that meet or exceed OE specifications.
- Beck Arnley: This brand sources parts from a network of global manufacturers, often re-boxing the original OEM part in their own packaging. They focus on matching OE form, fit, and function.
- Standard Ignition (SMP): A well-established brand in the aftermarket, offering a solid balance of quality and price.
- Holstein: A growing brand known for producing quality sensors for European vehicles.
Tier 3: Budget-Friendly
These brands offer significant cost savings but have mixed reviews regarding long-term reliability. They can be a viable option for a quick fix or if budget is the primary concern, but be aware of the potential for a shorter lifespan.
- URO Parts: A popular budget brand for European cars. While some of their parts are excellent, their electronic components have a reputation for inconsistent quality.
- Facet, Four Seasons, Global Parts, True Tech, Walker Products: These brands fall into the economy category. They can work, but for a critical sensor on a 550i, consider them with caution.
Cost of Replacing the Engine Coolant Temperature Sensor
| Part Type | Price Range |
|---|---|
| New Aftermarket | $19.03 - $68.69 |
| New OEM | $50 - $75 |
| Shop Labor | $134 - $197 |
Note: Labor costs can vary significantly based on which sensor is being replaced. The lower radiator hose sensor is much quicker to access than a sensor on the engine block.
Frequently Asked Questions
Where is the coolant temperature sensor on my 550i?
It depends on your model year. On the 2006-2010 E60 550i, there is one in the lower radiator hose (passenger side) and another on the engine near the thermostat. On the 2011-2016 F10 550i, the most commonly replaced sensor is also on the radiator outlet hose. Always verify the location for your specific year and engine before ordering.
Can I replace this sensor myself?
For the sensor located in the lower radiator hose, yes. It is a very DIY-friendly job. It is held in by a clip and can be swapped in under 30 minutes with minimal coolant loss if the engine is cold. The sensor located on the engine block is more difficult and may require removing other components to access it.
What happens if I ignore a bad coolant sensor?
Driving with a bad sensor is not recommended. It can lead to poor performance, terrible fuel mileage, and a constantly running fan. In a worst-case scenario, if the sensor fails to report a true overheating condition, you could cause severe and expensive engine damage, such as a cracked cylinder head or blown head gasket.
Were there any recalls for the 550i coolant sensor?
No, searches of the NHTSA database and other public records did not find any recalls or technical service bulletins (TSBs) specifically for the engine coolant temperature sensor on the 2006-2016 BMW 550i.
Technical Specifications
OEM Part Numbers: 13621433076 13621433077 13627797957 13628650714
Typically a 2-pin thermistor sensor. One sensor is a clip-in style for the radiator hose, while another may be a threaded style for the engine block or thermostat housing.
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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 550i:
- 🛍️ Shop This Part
- Is Your 550i's Coolant Sensor Failing?
- Common Symptoms of Failure:
- A Note on 550i Generations
- Choosing the Right Aftermarket Sensor
- Tier 1: OEM Supplier Quality
- Tier 2: Reputable Aftermarket
- Tier 3: Budget-Friendly
- Cost of Replacing the Engine Coolant Temperature Sensor
- Frequently Asked Questions
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