I have about 500 miles on my first run of GC. Since I have put it in, I've been getting a loud ticking noise at cold start for an extended amount of time (say 5 minutes). M1 used to do this only when really cold and only for 5 to 10 seconds. I just did an ARX treatment and for the rinse I used Penz 5w-30. The dino had absolutely no start up noise at all. The weather has reamined around 30 degrees on average, both with the dino and GC. Could anyone help me figure this out? Should I change out the GC? I'm worried that its doing some real damage in there. My only thought is that since GC has a lot of esters that "seep", maybe its getting past the anti-drain back valve? BTW - the vehicle is a 2001 F150 with 4.2L V6 and the filter is the stock size Motorcraft. The motorcraft has a silicone anti drainback valve.