Today i changed airfilter from stock to K&N it was freaking hard and way too many screws to unscrew. Anyway, after i changed it and put evertying back together, i've noticed that clicking noise that i never heard before. I have some clicking noise near radiator, i was told that its coming from tensioner(t-belt, fan belt, water pump, and something else replaced 2 weeks ago) so it was ok. but since i replaced that filter i noticed clicking noise near firewall kind of behind the engine. Does anybody know whatit could be?