I have a 1998 Bonnie SSEi and I've got a head scratcher of an engine noise. Last fall I did the LIM and UIM gaskets and replaced all with GM parts. This car had a slight lifter tick when I took it apart so I decided to install a new set of aftermarket lifters supplied by a local engine shop. the sound in this video: http://www.youtube.com/watch?v=6KOy_LYBFTg
has slowly been getting worse to the point you hear in the vid. Now I didn't replace the rocker bolts as some have recommended on this site however everythings torqued to spec. I checked the harmonic balancer, and while its original (134K) it seems to be OK. (unable to rotate outer hub)I removed the belts and the same noise was there. In the video I show the engine running without any of the belts installed. This sound is worse in the extreme cold, but now we're back into the 20 C weather so its a little quieter. This sound is driving me nuts because I've already got a day'* labour into it just to do the intake gaskets, I really don't want to have to take it all apart again to replace a defective lifter.
Any help would be welcomed.
1998 Bonneville SSEi Supercharged