Originally Posted by
78fordman
I have a 2000 5.4 with 160k mi. i bought the truck with 113k and the noise has been the same since i bought it. I run the 820s filter with valvoline 5w-30 oil. this is not a dry startup problem either. it does not go away when hot but it get quiter. you only notice the noise at idle or low rpm, never going down the highway or under load. i have read a lot of knocking posts and have not found one with the same problem, any ideas?
You probably are aware of this already...but I'll throw this out there anyway. I think the recommended oil weight is
5w-20.
It could be the infamous exhaust leak...which masquerades itself in many ways...meaning it doesn't always sound the same from truck to truck or engine to engine.
have you done a compression check?