Gas and Oil Home Heating Furnaces - Eureeka! Could safety pilot make gas valve rattle?

I've been trying to diagnose that brief main gas valve rattle on closing. I wired to the main gas valves wires a relay and light bulb setup to "watch" the electrical signal to the main gas valve, and noticed once it clicked on and off and then back on without a rattle. To me this ruled out the gas valve. Signal is shakey. OK, now this carrier has a three wire safety pilot that was replace two years ago, and I really tried to figure out the schematic.

It appears that once heated, this safety pilot switch closes and the current is carried directly through the safety pilot to the main gas valve. I dissected the old one I kept and found a simple point-like switch with a slightly burned spot on the contact, not unlike car ignition points. I can't help but to think it is happening to this two year old one, and it is "going." I figure the electricity is arcing in the switch causeing the rattle, or a slower make/break/make. I filed the old broken one's contacts and checked it out, I may switch it out or dissect the newer one and peek at the points. I expect a really short life out of the filed points, now though.

Is it you'alls experience that these safety pilots go like this slowly, or suddenly. I figure when the professionals are called to a home it's because of a no heat, and the thing is totally burned. But what do you think of this theory???

Same answer

To be sure, I wired in a momentary contact switch to bypass what the safety pilot does, close the yellow to white wire. When pressed, the gas valve EVERY time make a sure solid click: Diagnosis must be a lazy safety pilot.