[chevmn]

I bought a new 92 K1500 pickup, and had a knock on startup, and when I had the truck in for a warranty issue (unrelated), I mentioned to the service mgr. He immediately asked what filter I ran, and at the time I used Fram filters. He suggested I get away from those, and at the time suggested I run A/C Delco, or at least a good filter with anti drainback feature, and likely the filter I was using did not. Keep in mind the K1500 of those years had filters on the side, so in my case it was always having to fill the filter on startup. I have not used Fram filters since, but I do not always run a name brand either, but in that case the truck never had a knock on startup after. Not trying to get into one of those arguments on what is the best filter, but he was obviously right on that one.