My 94 540ia withe 85k miles (bought it with 81K just after the block replacement) has just recently started a very slight valve train "ticking" upon start up & then goen away after about 30 seconds, ive been fanatic about maintence, 2-3k between oil changes, & iwas given a 1 yr 10k warranty for the new short block & also puschased a comprensive 3rd party warranty on everyting else. but what do i need to look for as far as wera & tear on the origianl valve train ?