I have a vs ecotec with 1.9 roller rockers that makes aticky noise pretty sure it is lifters have tried a lifter freeup additive did not even make a difference been told a few different things like using a engine flush, just replacing lifters, that the cam lobes could be worn and i would need to replace lifters and cam, im not convinced it is cam as it ticks worse on idle and goes away under revs and recently did a 1400 k roadtrip and it actually doesnt go to bad not 100% but.Who has had similar probs and what have you done
i know this might sound stupid but in some cases it not your lifters its actually your fuel injectors they tend to clog up
and make a ticking noise that sounds like lifters .Try runing some injector cleaner through it (as i said before It sounds
stupid ) but i had it happen to mine.
What oil are you running?