My car has 181,000 miles on it and has never had a major problem. However, the last couple weeks I have noticed that my RPM's run at about 3500 when cruising down the interstate about 70-75 mph. That is much higher than usual. I have also noticed that the air conditioner is not blowing air very well and it wont change from feet to defrost or any other setting for that matter. I can deal with the air problem but the high running RPM's I cannot. Could these two problems be related? If so what can be causing it?