Regard General Motors Top End Cleaner to correct the problem of engine ticking on start up. I have a 2001 Chevrolet Lumina (car) 3100 V6 that had all of these symptoms and similar dealer stories. I tried the Top End Cleaner recommended by bowtiebandit, and although it didn't make the noise go away entirely it did minimize it to the point of not being outwardly noticeable. It now goes away in a few seconds, rather than in minutes. More over this is an amazingly quite engine once it's warm and believe it or not it's a bit quieter now at full temperature. I also switched from 5w30 oil to 10w30 which is OK per the owners manual. Not sure if this did much, but I believe an oil change after such a procedure is a must. What's interesting is that the dealer recommend some "sort of chemical engine cleaning" for over $100 dollars to solve my particular problem. GM's Top End Cleaner sells for $7 at my local dealer. Just find a vacuum port that allows the stuff to enter the manifold directly. On my engine the throttle body is lower than the intake plenum so it doesn't work well using their directions. Hope this helps some of you.