Recently, I didn’t pay so much attention to posting. I didn’t report on the maintenance and oil change this year. I looked at my last post or the work of replacing spark plugs at the beginning of this year.
Today, I mainly came to ask for help, because my car has been running for more than a year, and the cooling fan always starts for no reason, and it is turning at a high speed, and it is not the kind of full speed because of protection. If the speed is divided into 10 levels, it is equivalent to level 8.
Because I can be said to be very familiar with this car after driving for so many years, I suddenly felt that the cooling fan in front started frequently last year, and as long as it was turned on, it would not stop until you turned off the engine. This is very wrong, because the fan will only start when the air conditioner is turned on when the water temperature is high, and the air conditioner will keep turning on, and the water temperature will stop for a while. And it keeps spinning when it doesn’t turn on the air conditioner and run on the highway.
Thinking it’s a cure! So when I stopped on the way, I touched the big water pipe behind the thermostat and found that it was cold, and the cooling fan was also spinning. Think of this to find the reason, the thermostat can not be turned on will cause the car up and down the two water temperature sensors of the numerical temperature difference is too large, the computer will force the cooling fan to start. So I bought a thermostat online and put it on for several months. I just checked that the purchase record was 82 degrees bought in April 2021. At that time, I took down the old and new soaked water and saw that the old thermostat could also be turned on, but when I bought it and dismantled it, I was sure to install a new one, and then installed a new one. as a result, it is conceivable that the problem has not been solved. then began a network-wide search for supplementary knowledge, during the period also understand the working principle of Volkswagen cooling fans, feel quite advanced, other cars are high and low speed fans Volkswagen is duty cycle control stepless speed regulation, there is a control module integrated behind the fan. Also know the conditions and reasons for the fan to start. So he went to my friend who runs a repair shop and used his computer to read the data.

It was delayed until the Spring Festival. JD.com gave welfare to the Spring Festival Gala and received a few red envelopes, so he bought a popular water temperature sensor on JD.com. This drag was another spring, summer and autumn. On October 2, 2022, the left front wheel was removed on National Day. And the fender in front of the left, the water temperature sensor at the entrance of the water tank was removed, and the resistance value was 2.5K. At room temperature, about 2.5K bowls of hot water are thrown into the new and old bowls of hot water to measure the resistance value again, so it is misjudged again, the same sentence is taken apart, bought and bought, new ones are still installed, and the old ones are kept in reserve. After being installed, I added some antifreeze and drove to the test drive when the fan was not started. But then it was the same halfway when I drove it again. Then I checked the temperature sensor at the outlet of the engine and found that the pin of the sensor plug was a little oxidized and corroded. It should have been sprinkled with antifreeze when the tee was replaced that year. I want to buy another plug to match the sensor I changed last time to replace this place. So I bought a few yuan.