After using a K&N oil filter for one week, I noticed a more pronounced "clicking noise" that resembles a knock or ping like sound upon idle or acceleration. When changing the K&N back to a Motorcraft, which most suddenly stoped the noise, I noticed some silver colored (aluminum) thread fragments on the oil filter itself. I just bought a case of these from Ford...all have the small flakes of aluminum on the filter threading. A while back I noticed in my pan those same metalic flakes and thought they were comming from my engine. So, my hypothesis is that the cause of some of our knocking/pinging noise is from the anti-drainback valve on the oil filter, and the small fragments of metal like material that we sometimes see in the bottom of our oil pans is from the oil filter itself.

what do you think?

 

I don't know about yours but 93 octane
will cure my ping so it ain't the filter. I'm
just not into $1.90 a gal. to fix something
that shouldn't be there.