i started noticing this sound a few months ago but i couldnt remember how my engine normally sounded. its gotten a little more noticiblenow. when my engine idles it sound like a constant tapping noise. my dad mentioned that i might need to adjust my valve lashings or something, and that the noise means that i could start to have some problems soon. i put close to 600 miles on my car a week, and i push it sometimes when i am on the highway. can anybody tell me if they have seen this before. my dad said that usually when he has seen this problem on cars, if he put more il in thaat it went away. my crankcase was as full as i could safely get it though. also, i think this noise could have started around the time i switched to synthectic oil. im pretty sure that it was a mistake to switch to synthetic bc my car had like 102000 miles on it when i did. other than this noise, i seem to have a very small leak from the bottom of my crankcase. it isnt dripping or anything, but when i changed my oil the other day, i could see a glaze of oil over about 60 % of the bottm of the crankcase. thanx for any help