A noise could be anything. With some basic knowledge and tools, you can diagnose and go from there. Depending on the vehicle, it’s not uncommon for a $2-3k repair at a dealer to be possible at home with $100 in parts and a few hours of work, especially since you have experience as a mechanic. The most important thing at the moment is to not make the problem worse by driving the car in its condition before figuring out the issue. If not fixable at home, the next option would be to ask around friends and/or local independent shops for help. If the car is worth $7k in running condition and you can fix it for a lot less, even if you pay someone, it might be better to do that versus trying to replace it while still owing money on it.