The low oil pressure light starts to flash rapidly when I am braking at low speed while in gear, for example slowing for a speed bump. It also did it when I was trying to move from a stand still using only the clutch with no gas but the engine was not shaking or anything. It seems that the problem started once I switched to synthetic oil which weights 5w30 (recommended) and the continental oil was 20w50 which seems counter intuitive since it is a lot lighter. I checked the oil level just in case and it seems to be fine. The engine sounds a lot quieter after switching to synthetic and is less shaky. The car is an 06 Chevy Aveo 1.5 SOHC with 270k KM on it.
Is my problem a failing oil pump or could it be something else? Is damage occurring to the engine every time the light comes on?
Edit: now the light is flashing during idle and goes away with throttle does this confirm a bad pump?
Edit #2: Okay so I was confused as why it didn't light up at all yesterday but did do so today and the day before yesterday, I believe because it only does it after driving some very steep hills with wide turns on my way to work other than that the light doesn't seem to flash at all during my other routes, my guess is because the oil moves around the sump starving the oil pump but should it not go away after finishing those hills? it seems to last minutes after and it did worse the second time than the first?
Edit #3: Disregard edit #2 the oil light seems to start flash whenever the engine is put under high load and then letting it idle however if I rev the engine higher than idle it goes away, does this mean it has a bad bearing?
EDIT #4: Alright the light no longer flashes after changing back to 20w50, does this confirm that the bearings are going bad?