I don't know how you classify damaging sounds. If its high tone tik tik or tek tek sound, usuallu its tappets, VVT mechanism, belts and bearings. If its low tone tok tok or thuk thuk sounds then means likely failure liao.
i indicate "IF" crankshaft bearings or shims or possible valve hitting cylinder based on the sound. If it is lower tone. It can't be higher tone because those components are at the lower parts of the engine. Any hits in the parts would channel all the vibration through the engine and car body. If you have engine sthethescope is better.
I suspect these items because over night engine oil would go low down in the oil pan. If you don't have enough engine oil would only make the sound last longer and louder.
I could be wrong. But this is based on my experience. Some from my engine some from the cars my mechanic fixes.
It could just be small noises that made you paranoid. hehehe. In the end if its hard to know, get your mechanic to hear it. Maybe you could record the sound with you handphone and put up a link. <--- (Good idea or not?):shades_smile:
