Dr. Pappas
As in the case of many analogies, that which you used ["...looking up the
tailpipe (of your truck) and telling that it has a bad piston."] is not a very
good one. Many engine problems can be diagnosed by "looking up the
tailpipe"...and seeing whether there is a discharge of water vapor,
oil-associated smoke, etc. Likewise, one can, strangely enough, diagnose
engine problems by "listening" via a long screwdriver held to the wall of the
cylinder head.
I think Albert Santos III's E-Mail is well-directed. Perhaps your responses
have become too Pavlovian.
David F. Oetinger, Ph.D.