At what temperature does the Passat B5 fan operate?

[ZoeyLee]

It operates around 90 degrees and starts at 95 degrees. Working principle of Passat electronic fan: The car's electric fan is controlled by a thermostat. When the water temperature rises to the upper limit, the thermostat turns on the power, and the fan starts working. When the water temperature drops to the lower limit, the thermostat turns off the power, and the fan stops working. Methods to determine if the electric fan is good or bad: Check the color of the coil at the fan motor's ventilation port for any signs of burning. If there are burn marks, it means the fan motor coil can no longer be used. Turn the shaft by hand to observe its operation. If it operates with difficulty or is not smooth, it indicates that the internal bearings are lacking oil or the rotor is scraping. If scraping occurs, in addition to adding oil and cleaning, the bearings on both sides must be replaced to eliminate the scraping phenomenon.

[Clarence]

My old Passat B5 has been running for over a decade. The cooling fan usually kicks in when the engine temperature rises slightly above 90°C, specifically around 93-95°C. During normal driving, the coolant temperature gauge stays in the normal 90°C zone, and the fan doesn't run constantly. However, in traffic jams or hot weather when the temperature climbs to 95°C, the fan activates to assist with cooling. One summer during a highway traffic jam, I got quite alarmed when I saw the temperature approaching 100°C before the fan started spinning rapidly. A friendly reminder: if the fan is delayed or fails to start, it might be due to aged relays or insufficient coolant. Regular checks for dust accumulation on the radiator are essential - cleaning it can improve cooling efficiency and prevent premature fan wear. During every maintenance service, I always ask the mechanic to test the fan's response. This car is truly durable, and its fan system has proven quite reliable.

[McRyder]

Having repaired many Passat B5 models, the fan activation temperature is set between 93°C and 97°C, automatically controlled by the temperature sensor. During idle or low-speed driving, the fan operates at low speed when the temperature reaches around 93°C, and switches to full speed at high speed when the temperature rises to 102°C. If the fan fails to respond, first use an OBD scanner to read the data stream and check the actual temperature. Common issues include blown fuses, poor wiring harness connections, or faulty thermal switches. During inspection, test whether the coolant circulation is unobstructed to avoid blockages that could cause overheating. Abnormal fan operation increases engine load, potentially leading to higher fuel consumption or thermostat damage. It is recommended to change the coolant every two years to maintain system efficiency.

[MacLeila]

I just bought a used Passat B5 and was curious about when the fan kicks in. After checking some materials, I found that the fan automatically starts when the engine temperature reaches about 95 degrees Celsius. During normal driving, the temperature stays stable around 90 degrees, so the fan rarely operates. However, when stopped at a traffic light, the temperature rises and the fan turns on, making noticeable noise. When the dashboard coolant temperature gauge reaches the middle position, it indicates good heat dissipation. If the fan doesn't work for a long time and the engine temperature soars beyond 100 degrees, the warning light will come on. The first time I noticed this issue, I went to a repair shop. The mechanic said the fan's response is a critical part of the system's protection and shouldn't be taken lightly. During my next maintenance, I'll specifically remind them to check the fan's functionality.

[OViolet]

My Passat B5's fan is set to operate between 93 to 95 degrees Celsius, which is a standard design. This temperature point ensures the engine operates within an efficient range while saving fuel. If the fan activates too late, it can lead to overheating, increased fuel consumption, and even piston damage. During summer high temperatures, frequent fan activation increases battery load, so it's important to regularly test the coolant concentration to prevent freezing point changes. Abnormal fan behavior, such as delayed activation, may be due to blocked radiator fins or a stuck thermostat. I make it a habit to clean the dust accumulation on the radiator fins every 5,000 kilometers to reduce fan pressure and extend component lifespan. Neglecting this can cause the fan to consume excessive electricity, burdening the entire vehicle's electrical system, which is not worth the trade-off.