If it just started happening all of a sudden, it could maybe be an injector or something fuel-related.
You're gonna be under the cover for the injectors anyway, before you pull any, check and set your valve lash. If they're too loose, you'll find the engine is a lot noisier.
A lot of guys will get meticulous to set all the valves to a "go/no-go" tolerance (i.e. you can fit an 0.010" feeler but not a 0.011" feeler) and some just look to make sure they're not too tight or too loose. I fall somewhere in-between. The ones that were the loosest when I did mine a few weeks back, I took them back to a go/no-go tolerance, the others that were close enough to middle spec, I just left them. It made a difference, and some day when I'm bored I'll probably go back and spend the time to get them all right on the money. It was just too darn hot that day to mess around too long!
You're gonna be under the cover for the injectors anyway, before you pull any, check and set your valve lash. If they're too loose, you'll find the engine is a lot noisier.
A lot of guys will get meticulous to set all the valves to a "go/no-go" tolerance (i.e. you can fit an 0.010" feeler but not a 0.011" feeler) and some just look to make sure they're not too tight or too loose. I fall somewhere in-between. The ones that were the loosest when I did mine a few weeks back, I took them back to a go/no-go tolerance, the others that were close enough to middle spec, I just left them. It made a difference, and some day when I'm bored I'll probably go back and spend the time to get them all right on the money. It was just too darn hot that day to mess around too long!