4.3 knocking...

[Redriverranger]

I had a 4.0 ford knock like hell for about 10 minutes once when I first installed it. I wouldn't have given you two cents for it and was about to yank it back out of the truck. Then I thought what the hell, what have I got to lose and revved the hell out of it. It got quieter. I pushed it a little more and it finally got very quiet and was an extremely good motor for about 4 years. I know this is probably the exception to the norm, but I feel that the engine had some power steering fluid or tranny fluid that ran down in the intake, as it was sitting at a junkyard under a shelf with other engines above it that created a hot spot, or detonation point when I started it, hence the knock. That is the only way I can explain what may have caused it as it truly ended up a great engine.