I have a 2002 GC ES with an A/C problem. The temperature here in Iowa got up to 85 and the A/C will not engage. I have checked the fuses, and the relay, all are good. I had no problems with this last summer. Also, there is a terrible knocking in the motor (3.8l V6 with 42k) at idle and crusing speeds. I tried Lucas oil and 10W30, but it only worked for a week.
Thanks in advance for your help.