A little over a year ago I bought a new car for my wife and it has a 24 valve V6 engine. I drive it now and then and I noticed that on cold startup, it has some valve train noise until the oil starts to circulate. After searching this website I decided to switch from the OEM Mopar filter to Motorcraft. I drove it after the oil/filter change and the cold start-up noise was gone. Well, it's been 2000 miles since the oil/filter change and I drive the car again the other day and the noise is back. Does the Motorcraft filter not have a good bypass valve? I'm willing to spend more money on a filter. I think I need one with the best bypass valve I can get. Any suggestions?