My heater/air conditioner fan is noisy

I've done this job 6 times now and it gets easier every time. It's your blower motor. The e30's get filthy over time and the heat resistor gets covered with grime, thus having a bad signal. You will need some non-flammable electrical parts cleaner and some patience. The blower housing is located in you firewall at the back of your engine bay. I believe there are 5-7 bolts that hold the cover down. The blower is located with a plastic shroud, be careful of the plastic retaining clips. They are both fragile and a pain to put back on correctly. The resistor is below it, and looks like a wire coil. Clean it all. Using the flammable variety can turn your cleaning job into a fire breathing dragon very quickly at this point. Test the blower with the cover off and reassemble. Have fun!

may be somting inside or damesh in the motor