Don't assume causality from coincidence.
I have had two times when my oil pressure did start dropping and go to zero, and they were both when I was overdue for an oil change. It was not the actual oil pressure, but it was the oil pressure sender. I think it must be easy to clog or jam somehow.
Anyway, the tapping on startup is random on my Tahoe and totally unrelated to indicated oil pressure. Some mornings I get it, some mornings I don't. Also, cold or hot does not seem to matter. I think it may be related to if the engine was in 4-cyl or 8-cylinder mode when it shut off. That is my best guess at this point.

 

Very true... proper testing will determine if recent events are related or merely coincidence...just throwing the info out there in case there could be a correlation.

I'm used to changing the oil every 3 months or 3000 miles.. but since buying newer vehicles (my other is an 06 BMW) it seems like that standard no longer holds true according to factory instructions. I haven't changed the oil on my Yukon since I bought it (used obviously) in January this year. Yet the computer shows that I have 30% oil life left.

Good advice.. I'll have the oil changed and see what happens.

Thanks!!!

 

The oil pump on the newer Small Blocks is in front. Your engine has a variable displacement oil pump. Some of the pressure regulation valving is in the cast aluminum oil pan.

True low oil pressure will result in all the lifters "tapping". Could be sensor like another poster here, could be regulator and real.

The resonator... is for pass by gubermint noise. Don't sweat the back pressure.

I too was an original Mr. Goodwrench when that came about. Went to school for Electrical Engineering for self defense.

FJ they are always supposed to go back to V8 before the crankshaft stops rotating.