You probably can’t fix it yourself, and your mechanic might not be able to, either. Almost a metaphor for our times. See Scotty Kilmer explains new car repair.
By the way, this guy’s great. In various places he says: Honda makes the best engines but Toyota makes the best cars. The Ford 150 is the best mid-size pickup, followed by Toyota Tundra. Toyota Tacoma is best small pickup, followed by much the cheaper Nissan Frontier. The Toyota Camry & Corolla are the best cars with Honda Accord and Civic close behind. Stay away from Chrysler/Fiat, anything European, and Nissan cars (not trucks) after 2000.
He’s kind of a replacement for NPR’s Car Talk.