How do you find the coolant temp sensor on 2002 A6?

Answer 1

You will need a flashlight! It is on the back of the engine on the passenger side under the air intake hose connected to the silver "Y tube". You will have to remove the Accordion hose and then push back some of the wires under that to see 4 wires. It will be pretty hard to see. I had to remove the mylar sleeve over one of the hoses in order to almost see it. Keep looking its back there. It is going to be a pretty hard task to get your hand in there and remove the retension clip. I had to pry it off with a screwdriver. Once that is removed you can pull up the sensor and connector. It is alot easier to get it off if you pull them both out. Now you can pull the sensor closer to you to look at it. You will have to use the screwdriver again to depress the button and disconnect the wiring mechanism from the sensor. You will probably lose the O-ring, so make sure you get that out before you put the other one in. Connect the sensor to the wiring housing and place back in. The retension clip is really hard to get back in. It will take 10 tries or so to get it in the right groove. After that reassemble everything and you should be good to go. I started my car to see if any coolant leaked. Its a good idea you don't want to get to far down the road and realize you didn't quite put it in there right. Someone else wrote up about a 2000 A6 2.8L. This sensor isn't in the exact same place, but its close and it will give you an idea where to look. He has plenty of pictures. It was a great help to me. http://forums.audiworld.com/a6/msgs/456952.phtml You will need a flashlight! It is on the back of the engine on the passenger side under the air intake hose connected to the silver "Y tube". You will have to remove the accordion hose and then push back some of the wires under that to see 4 wires. It will be pretty hard to see. I had to remove the mylar sleeve over one of the hoses in order to almost see it. Keep looking its back there. It is going to be a pretty hard task to get your hand in there and remove the retension clip. I had to pry it off with a screwdriver. Once that is removed you can pull up the sensor and connector. It is alot easier to get it off if you pull them both out. Now you can pull the sensor closer to you to look at it. You will have to use the screwdriver again to depress the button and disconnect the wiring mechanism from the sensor. You will probably lose the O-ring, so make sure you get that out before you put the other one in. Connect the sensor to the wiring housing and place back in. The retension clip is really hard to get back in. It will take 10 tries or so to get it in the right groove. After that reassemble everything and you should be good to go. I started my car to see if any coolant leaked. Its a good idea you don't want to get to far down the road and realize you didn't quite put it in there right. Someone else wrote up about a 2000 A6 2.8L. This sensor isn't in the exact same place, but its close and it will give you an idea where to look. He has plenty of pictures. It was a great help to me. http://forums.audiworld.com/a6/msgs/456952.phtml