alright, well i started my first auto rx treatment about 600 miles ago. and today i started to get some rod knock on start up. well i think it started today, since my car is pretty load...its hard to hear things like that. im just wondering if a heavily soiled or clogged oil filter would cause that. my oil pressure is fine, but it just takes about 4 seconds for it to rise. im running delo 400 and M1 mix. or could that be my problem. any help would be appreciated since this is my daily driver with 200k miles on it. oh yeah, its an 89 ford mustang 5.0L. thanks for all the help guys