Hello ladies and gentlemen,
I bought a second-hand car about 2 months ago which started developing a ticking sound from the engine bay. 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. I have even tested it in a tunnel to make sure it disappears. This only happens when the car is warm as well. When I start the car in the morning the sound is not there and doesn't come until the car has been driven/warmed for a bit. The previous owner was a very old man in his late 70's and he had no crash/maintenance logs. He never drove the car above 90KM/h when he had it in his possession. When we first bought the car it was near perfect until I pushed it to around 120KM/h a week after we bought it. It started making the sound from that day. We thought maybe the oil is bad so we went and did an oil/oil filter change. The sound went away for around a couple days then came back so we took it to a mechanic. He disassembled the engine and told us what the problem was but I am not a car-savvy person and don't remember what he told us. I only remember him saying that the "Crankshaft" needed changing. Once he gave us the car back the sound had completely disappeared. It stayed like this for around a month until the sound came back around 2 weeks ago. From then we have changed the oil/oil filter twice. Each time the sound disappeared for a couple of days and then came back. I wanted your guy's honest opinion before we have to take it back to another mechanic and get ripped off again.
Chevrolet Lumina 2007 V6 3.6L Automatic 4-Speed
280,000 KM Mileage
Check Engine light on
Oil being used: Mobil Super 1000; 20W-50 XHP
Link to video of my car:- https://www.youtube.com/watch?v=zMfMyhurojE&t=1s
Recent maintenance -
Transmission oil change only because of leakage(Not filter)
A/C compressor electricity wire was loose.
P.S.: I live in the middle east where the temperatures can hit 40C Mid-Day
Update 1: I went to a mechanic who advised me to do an oil change to 10W-30 which is the correct one and drive for a week or two to see if anything changes. After 2 weeks of driving I have found this: The sound will still be there when cold BUT, it completely disappears after driving the car for a minimum of 10 to 15 minutes and that is something which is really confusing me.
I also did a computer check for the check engine light and these are the codes which came up:
P0131 - $07E8 - O2 Sensor Circut Low Voltage Bank 1 Sensor 1
P2251 - $07E8 - O2 Sensor Negative Current Control Circut/Open Bank 1 Sensor 1
P0521 - $07E8 - Engine Oil Pressure Sensor/Switch Range/Performance
The check oil light also sometimes comes once in a while but much less than before.