Old hydrolyic valve lifters making moises, so I have them replaced with new lifters, but still making noises.
So I have the new ones checked if there is oil in the lifters. There is no significant oil in them. I believe the lifters' oil supplies pipes and so on, need to be clean/cleared up for oil to flow better. I'd appreciate any recommendations for solvent or liquid solution used and methods!. Note the oil pump is working fine, with enough oil pressure.