Car owners know it is critical to perform regular maintenance on their vehicles, but quite often, the small parts get overlooked. Your Volkswagen’s coolant temperature sensor (CTS) is one of those little components. This small and unassuming part is vital to your engine’s health. It directly affects the lifespan of your vehicle, which is why it is so important to observe and understand the signs of a malfunctioning coolant temperature sensor. In this article, we will talk about some of the signs to watch out for that could indicate a failing coolant temperature sensor.
What is a Coolant Temperature Sensor?
You may have heard the coolant temperature sensor (CTS) called by other names, such as the ECTS (Engine Coolant Temperature Sensor) or the ECT sensor. The coolant temperature sensor (CTS) is a small device that monitors and measures the temperature of the coolant (antifreeze) in the engine cooling system (ECS). This data is sent back to the ECU (Engine Control Module) or ECM (Engine Control Module) to determine whether the correct temperature exists to go through with the process of internal combustion. Correct temperature readings, which are determined by the coolant temperature sensor, are essential for your VW’s engine to be able to perform optimally. Therefore, it is critical that you have a working CTS.
Signs of a Failing Coolant Temperature Sensor
- MIL (Malfunction Indicator Lamp): If the CIL (Check Engine Light) or temperature warning light comes on, definitely have your mechanic do a professional diagnostic. The reason for the light can vary. Therefore, it is important to rule out other possible malfunctions first.
- Temperature Gauge: If the temperature gauge keeps fluctuating and approaches the red zone, it is time to consider checking the status of the coolant and the coolant temperature sensor of your VW. In fact, it is a good idea to have the entire cooling system checked out, as this is a very serious issue and can cause irreparable damage if left unaddressed.
- Bad gas Mileage: If your engine runs lean (too little fuel) or it runs rich (too much fuel), it will affect fuel efficiency. The coolant temperature sensor could be to blame for either scenario. The ECM (Engine Control Module) needs the correct temperature information so that the appropriate fuel-to-air mixture can be created inside the combustion chamber or the intake manifold. This allows for optimal engine performance and fuel efficiency.
- Difficulty Starting: If you notice your Volkswagen has difficulty starting in cold weather, this is a strong indication that you may have to check the coolant situation in your car. Often, a faulty sensor will cause this issue. The ability to cold-start has to do with the fuel-to-air mixture, which can only be regulated correctly by the ECM if it gets correct readings from the CTS.
- Stalling: If your VW tends to stall while idling or while you’re driving very slowly, this could be pointing to a coolant temperature sensor issue.
- Other Signs: Sometimes, a CTS problem manifests itself with subtle signs, like engine hesitation, black smoke from the tailpipe, or increased emissions. The only way to definitively know what exactly is causing these issues is to have a professional scan done on your Volkswagen. We can do that because we have the necessary tools and scanners.
The Best Time to Replace the Coolant Temperature Sensor (CTS)
Typically a coolant temperature sensor will last up to 100,000 miles, or even more if you perform regular maintenance on your VW. The key over here is “regular maintenance” and not wait until you see problems. A faulty CTS could be the cause of your engine to fail completely and cause expensive damage. Since this is an indispensable part of your VW’s engine, it’s best not to dilly-dally. It’s also important to ask for OEM (Original Equipment Manufacturer) parts. At our service centers, we only use OEM parts.
Visit Heynneman European Today
At Heynneman European, we are trained, ASE-certified (Automotive Service Excellence) mechanics who specialize in European cars. That means we are not only great at repairing your car, we also provide excellent customer service. We will listen to you and then offer suggestions. We are your partners. Allow our 70 years of combined automotive experience to guide you through any of your car problems. Give us a call or schedule an appointment to come in. Drop by any of our locations in California: Larkspur, Kentfield, Corte, Mill Valley, San Anselmo, Fairfax, and San Rafael.