retorque heads to solve issue?

Obviously something is amiss if I'm getting some soot on the block.
Soot or oil residue with dust? Soot could mean more serious problems from where you say you see it...the other is seepage. The expansion rate is different between the 2... and I dont really see cometics NOT weeping oil. But that is just what I see after years of service with them.
Also, are you saying that I need to drain all the coolent out if I'm simply backing off the bolts a few pounds then retighting them?
Obviously not. Everyone's idea of re torque must be different than others though.