Last4KRunning

The heater fan on my 87 4k quattro was very noisy at times and would bog down when squealing. I pulled it out yesterday and replaced it with another one I had. It is not a real bad job. Take of the black plastic cover then take out the four bolts that hold down the white plastic plenum. Remove the vacuum line and electrical connection. Then very slowly pry up on one side and then the other with a screwdriver to break the foamrubber weatherstripping loose from the body of the car. It will be really well stuck. Go slowly so you don't break the white plastic. Pull the plenum out, it is a tight fit. The cooling fan just has one screw holding it, it is under the big power resistor the drops the voltage for the lower speeds. You will have to rotate the fan around and sideways to get it out. It takes some playing around with to get it out.

To make the old fan last longer oil the plain bearings/bushings with light oil. I had a oiler with a long spout that came with a repair kit for my electric dryer. Oiling the back bearing is no problem as it is exposed. The end with the fan blade is another story. I ended up carefully drilling small holes 180 degrees apart near the center of the plastic fan blade assembly. This allowed me to drip oil (hopefully)onto the other bearing. By placing the holes 180 degrees apart and close to the center of the blade assembly I reduced the chances of having vibration from an unbalanced blade assembly.

Last4KRunning

Note, the fan motor is the same in all the 4000s that I have worked on 81 to 87 fwd and quattro