I have 134,000+ miles on my 17 Forte and have no problems like that. Hell, I run my oil changes between 8,500 to 10,000 miles. My car hasn't really had any problems besides a crappy plug on the blower motor, trunk latch, faulty coil and a love for burning out the low beam headlights. All minor crap. I'm changing the oil today on it today as while I'm approaching 150,000 miles I may get to 7,500 mile oil changes. Mobil1 and a Mobil1 filter. I have no idea what's going on with your car, but I really don't think it's timing chain related. Some of these 2.0 engines have over 200,000 miles on them and are still running the original timing chain. You DEFINITELY need to get a second opinion. All of my miles come from rural living and a wife that has multiple doctors in multiple cities. She's all effed up!