I have been "lugging" my engine for a couple of years now when driving in town.
I have noticed that the rod bearings are making noise. I believe it is from the very low oil pressure at idle and the fact that I am pushing close to 300 ft lbs just above idle. That is a ton of wear when there is not enough oil pressure.
I will be tearing the engine down to put new bearings in it and I hope the crank is still ok.
As of late, I have been trying to avoid lugging.