i’ll have to remember that one crankshaft seal didn’t even cross my mind but it makes sense.Since it makes the chirping at start up I question whether it is related to the suspension. My Cruze recently developed the chirping (intermitent) and, although it had no oil leak whatsoever, it turned out to be the front crankshaft seal. I discovered this using a stethoscope. Replaced the seal and the chirping disappeared. You may want to give this a try.