umm i'm not too sure.. what exactly do you mean by pattering... is the pattering like a light vibration in the clutch pedal? or is it something you hear? also is the car in motion or are you sitting in idle?Are you sure it's only when the AC is on? Well when the AC comes on your engine has to work harder you know to turn the AC belt. so in idle turning ac on should probably jump your RPM's up to 1,000-1,300 maybe. So try running your car at low rpms with no ac on and see if you hear it. If so then it has nothing to do with AC and it would mean it only happens when the engine is under a light load. Which probably means one of the bearings are just starting to wear out.... but I'm not 100percent sure. I was just trying to use some logical reasoning... but i can ask some of the other technicians at work tomorrow, and see what they have to say!

 

I checked again and i kinda hear it when the ac is off but its a lot more noticeable when its on...the sound is kinda like when you stick a pen in a fan...sorta lol...

 

throw out bearing

 

I am order a Spec Stage 2 clutch w/ throw out bearing in there first week in June. I hope that fixes the problem.

 

it will

 

it's not the throw out bearing since you hear it with the clutch engaged, but it's good to go ahead and replace it but you should change your pilot bearing also. Most clutches come with new pilot bearings and the center allignment tool to line it up with the clutch. also when you change your clutch be sure to resurface your flywheel, to take out any minor heat warpage.