I have been having a problem with lifter noise at start-up. This only happens after the oil has been in there for 2,000 miles or so. I first noticed this with penzoil 5w20 at about 1900 miles after the truck sat overnight I would get a little ticking for a second or two. I switched to schaeffers 5w30 and the ticking was gone no matter how long the truck sat. Now after 2,000 miles the ticking is back in the morning. My question is do you think the oil is thicking up causing it to flow slower in the morning, or mayby the additive package is getting depleted? I just bought some Castrol syntec blend 5w20, I will change it this weekend and see what happens.