Why does the Tiguan's cooling fan keep running when the water temperature is normal?

[LilaLee]

This is caused by a stuck thermostat switch. It is recommended that the owner visit a 4S shop for inspection by professional maintenance personnel or replace the water temperature sensor. Below is relevant information: 1. Working principle: Under normal circumstances, when the car's water temperature reaches a certain level, the thermostat opens, allowing water in the radiator to circulate. The sensor detects this and then the radiator's electric fan starts running. 2. Consequences of a damaged water temperature sensor: If the car's water temperature sensor is damaged, the car may experience difficulty in cold starts, abnormal operation of the water temperature sensor, resulting in sluggish acceleration, and sometimes unusual noises may occur.

[RicardoFitz]

The car's water temperature is normal, but the fan keeps running non-stop. I've encountered this issue many times, especially in the Tiguan models. The main cause could be a faulty temperature sensor in the cooling system, which mistakenly thinks the engine is still overheating and keeps the fan running. Alternatively, the fan relay might be stuck, continuously supplying power. Another possibility is a malfunction in the control unit (ECU), sending incorrect signals. Don't forget to check the air conditioning system—if the AC compressor is running, the fan will also operate continuously to dissipate heat. Try turning off the AC to see if the fan stops. I recommend using a car diagnostic tool to read the fault codes first, as it can quickly pinpoint the root cause. A constantly running fan is not only noisy but also drains the battery, which can lead to difficulty starting the car over time. Addressing the issue promptly is crucial to avoid minor problems turning into major repairs. It's best to visit a 4S shop or a trusted Volkswagen specialist for inspection—replacing parts is usually inexpensive and ensures peace of mind and safety.

[VonQuinn]

My Tiguan is just like this, the water temperature display is completely normal, but the fan keeps spinning like crazy, which is really annoying. At first, I thought it was normal cooling, but a friend pointed out that something was wrong. I suspect the reason might be that the temperature control switch or sensor has aged and failed, unable to read the accurate temperature. I tried resetting the ECU and checking the fuses myself, but it didn’t help. Later, a technician checked it and said the fan relay was stuck, and replacing it solved the problem. When driving, pay attention to avoid long idling or parking in high-temperature environments to prevent the system from overheating and misjudging. Besides the loud noise, a constantly running fan also accelerates motor wear and increases fuel consumption, so early repair when abnormalities are found is key. Other Tiguan owners in the group have also reported similar issues, mostly easily resolved, so don’t worry unnecessarily.

[VanCaleb]

The Touareg's fan continues to run despite normal water temperature, indicating a control system misjudgment requiring additional cooling. Key possibilities include temperature sensor accuracy drift, fan drive circuit failure, or external interference, such as air conditioning demand forcing the fan to operate. A simple troubleshooting step is to first confirm the air conditioning is turned off and observe if the fan behavior changes. Similar records are common on the Touareg platform, and using a multimeter to measure relay voltage can help locate the issue. For prevention, regularly replacing coolant to keep the system clean can reduce faults, with minimal overall impact on the vehicle.