Thank you for the replies. I should probably clarify this a little more. I have tried a lot of different filters and the results are almost the same. After an oil and filter change the engine is very quiet on start up. You can hear the tensioner pump up, but it's not really at rattle. But after about 900-1600 miles on the oil & filter the engine starts to rattle on start up for 1-3 seconds, if I don't change the filter within a hundred miles or so, the noise progresses to a rod knock. I have done UOA's on the oil and when I dig them out I will post them. All three of these engines shear the 5w20 down to a 10wt at 100cst in 3k miles. No fuel dilution recorded. I have used amsoil, pennzoil, motorcraft, and am currently trying schaeffers 5w20 (cool green color). On the oil filters after the rattle starts, I change the filter and the rattle goes away. The length of time before it starts again depends on the filter. Motorcraft 1.4k, pure one 600 miles, Eao 1.5k, supertech 200 miles, napa gold 1.4k, carqueat blue (wix) 1.5k, mobil 900 miles. On the 04 Crown I took it to the dealer with the same complaint at 30k, they said no problem, it was in the middle of an OCI, by the end of the OCI, the rods or crank knocked for 5-10 seconds before they quieted down, oil pressure idiot gauge said I had oil pressure 1 second after start, but you couldn't tell by the engine noise. They torn down the engine, said there where grooves in the crank and bearings and several of the cam journals where scored. They replaced the motor with a rebuilt, no crate engine was available at the time. Now it's half way through a dealer done oil change with 10.9k on the rebuilt and it's rattling again. It driving me crazy. I can't blame it on driving style/conditions as I don't drive the 05 it's the GF's DD, the 03 is my DD, and the 04 is the weekend car, we both drive. I would have to remote the filter to go to a larger size, not my first choice. Would a pre-oiler be worth considering.? I think the oil shears down enough to loose prime at the pump, but it's just a guess.