This isn't really a specific maintenance question, more so I'm just curious how the more experienced people here go about troubleshooting your cars.
I drive a 2010 Audi A5 2.0 TDI, its been a flawless experience so far both in terms of driving and maintenance (the majority of which I do myself). Its sitting at around 145,000km mileage.
Except for this one noise, it started a month ago and is sporadic, appearing out of nowhere from the front left wheel for awhile. It kind of sounds like scratching your nails on a chalkboard, its more common when I'm turning left and gets louder when I do.
It can get pretty loud so naturally I've been going at that portion of the car for the past couple weeks trying to find the problem. I keep finding something that's worn out/would explain the noise and replace it, and yet the sound persists.
I've changed the brake guards, brake discs, brake pads, new calipers (All OEM), removed every spec of rust and recoated any affected surfaces and applied grease to anything that needs it. I'm now preparing to swap out the wheel hubs (with wheel bearings pre installed) but I'm having second thoughts.
I can't keep throwing money into this car by guessing what it might be, I need to figure out exactly which part needs replacing before I spend more money.
So how do yall narrow down issues like the one I've just described? How do you approach issues like this with your cars without wasting a load of money?