I must be missing something. The gentleman with the formerly flawless O-360-CIF (Ask Paul: What causes a formerly flawless engine to run rough? May 19 issue) says he swapped the #1 and #3 EGT probes and the problem moved to #3 on the JPI. To me, an A&P/IA, that means the problem is most likely in the probe. Problems do not move from one place to another unless the component moved is bad. I suppose if he moved the probes and connected wiring that would explain his statement. But, if the CHTs are in the normal range and pretty much even, perhaps there is a problem with the EGT indication of the JPI, because a hot EGT would certainly give a hot CHT.
As a side note that I am sure will get me in trouble, I agree with you. Too many pilots that fly aircraft with multi-cylinder engine monitors expect the indications to be exactly the same on every cylinder on the engine. That will almost never be true. I have been asked to chase down problems because the #6 cylinder is running cooler than the #2 on a IO-520. Of course, the #6 is in the ram air blast and the #2 is buried behind two other cylinders and the heat generated by them. The multi-cylinder engine monitors are nice additions but there are many aircraft without multi-cylinder monitors that have run many engines to TBO and past without any problems. Let’s not forget that.
Dan Frandson
Boise, Idaho