Hello fellow car enthusiasts,
I bought a second-hand car about 2 months ago which started developing a ticking sound from the engine bay. The sound started 2 weeks after putting the wrong weight oil. I put 20w-50 in the car when 10w-30 is recommended. A week or two after the sound started I changed the oil back to 10w-30. The sound went away for a couple of days but returned. Leading me to do another oil change yesterday, the sound went away as soon as the new oil was in but started making noise again today. The sound is coming from the top/passenger side of the engine. This ticking sound is only there when the car is idle. It completely disappears when I go past 1000 RPM. The “Check Oil” light also comes on at random and stays on for 5 seconds at most then goes away. There is also a Check Engine light with trouble codes for the O2 Sensor in Bank 2. Could it be oil sludge preventing proper oil pressure or a dying Oil Pump? Can anyone suggest solutions or causes? I would greatly appreciate your advice!
The car is a 2007 V6 Chevrolet Lumina with 280k kilometres on it. The previous owner did an engine workup (Timing belt, Crankshaft, some bearings, etc.) at around 250k km.