Sounds like no oil/low pressure getting to the hydraulic lifters because oil is so cold and thick. Either switch to a thinner oil if you are way up north or just start it and let it idle for a few minutes, don't rev it. Different filters won't help. I highly doubt its piston slap, that would/can cause damage. I'd bet If you had an egine warmer, when you started it , it wouldn't make noise. Put a heat lamp under the oil pan to keep the oil warm and I'd bet when it starts it won't make any noise. My van sounds like a desiel for like 5 minutes or until it warms up when I start it in the winter time (15 to 40 degrees F ) when I don't switch the oil to 5 / 30 and still have the 10/40 or 20w/50 in it.
Oh yeah, the valve in the center of the filter is a safety valve. Should the filter get clogged, as a last resort this valves open under pressure and lets oil bypass the filter.
Last edited by itzmepete; 01-11-2012 at 06:48 PM.