Sporadic tachometer jumping?

Tachometer wants to jump up and down when engine is first started and also while this happens, temp gauge does not work and if I turn A/C on while this is going on it blows warm air. This only happens for about two or three minutes then when engine warms everything starts working correctly. I checked under hood while it was happening and the only thing I see and hear that is out of ordinary is down where the A/C pulley is, the metal seems to jump in and out against the pulley that the belt runs on. It will click loudly and seems to create a friction that in turn makes my rpm's jump. Was wondering if A/C condenser clutch is sticking causing the other problems or if tachometer is bad or has an electrical issue somewhere? Maybe MAF sensor needs cleaning? This car has been a great vehicle. All I have had to do is general maintenance. Also, my check engine light came on three weeks ago. Had it tested. O2 sensor needs replacing. Bank 2.

Well, tachometer has not jumped at all today. Why? Got me. Even turning on air conditioner did not cause anything. Here is a video of what it sounds like running today upon first start of day. Oh well, I did clean mass air flow sensor changed oil and air filter. Priced condenser and clutch assembly and o2 sensors. Haha just in case! Oh and also replaced a faulty headlight socket that was burned up.