When a head gasket fails, coolant gets into the oil. Coolant in the oil damages the main and rod bearings. There is a material called babbit on the surface of the bearing that gets removed.
Chances are you will need to drop the pan and change the main and rod bearings. You most likely have low oil pressure from the clearances from the bearings and that is why you hear the noise and the light is coming on warning you that you are very low in pressure.
Hopefully there is no damage to the crankshaft surface.
Friday, October 12th, 2018 AT 3:15 AM