My 2001 Buick Century has a engine knock when first starting up, then goes away after a minute?

So far I've changed oil a couple of times and used a Lucas oil additive, but it their still a tapping at start up. Should I worry about this? I was told that it might be the lifters, if it is can they be adjusted easily? Or should I just turn the radio up and forget about it? Other than that this car is a smooth rde.My 2001 Buick Century has a engine knock when first starting up, then goes away after a minute?Piston Slap, all the 3.1L %26amp; 3.4L engines around that time frame had that problem. GM said it was using redesigned pistons that supposedly had a coating on the piston skirt was to fix the problem. The only problem was they only put it on 1 piston %26amp; left the other 5 without. It actually doesn't cause on problems with the engine other than noise annoyance unless the coating on the skirt starts to roll up %26amp; wedges between the piston %26amp; cylinder wall which I seriously doubt yours has since it is that old of a model %26amp; probably will never get any worse than it has.

But no matter what you add to the engine will never quiet it down unless you replace the engine or pistons.My 2001 Buick Century has a engine knock when first starting up, then goes away after a minute?Lifters not adjustable. This is common issue. Best advice if it is just at startup and goes away turn up the radio and drive happily.My 2001 Buick Century has a engine knock when first starting up, then goes away after a minute?use 5w30 oil and lucas engine oil supplement