I ran into ticking problems with my m103 when using crappy oil and filters... Ended up buying mahle oil filters from allpartsexpress and using better synth oil and it sorted itself out. Near as I could tell (as could my local indy) the crap oil was gumming up the hydraulic lash adjusters in the head and the crap filter(thanks napa) was not providing adequate flow. Check out the filters, they are like $6 and are well worth it.