So this past January 2015 I heard a funny noise coming from the timing belt housing, so I had a mechanic check it out. Turned out to be a bearing in the water pump, so I had him replace the pump and, since he was in there, the timing belt. Fast forward to a couple weeks ago while driving I hear a loud tearing noise and the car stops.
Had the Aveo towed to the mechanic who opened it up and it the belt was partially chewed up but didn't break. It turns out the mechanic had dropped a bolt in the timing belt housing and it finally worked it's way into the crankshaft sprocket and tore up the teeth. The local mechanic replaced the belt and crankshaft sprocket, however the engine now runs rough during idle and surges. Although he tried his best, the mechanic could not figure out why the engines surges during idle now.
Anyone have any thoughts as to what is causing this issue? The engine idled fine before this.
I had the same mechanic replace the belt 5 years and when I went to pick it up, it had a similar issue, however, he was able to correct it. This time, unfortunately, he was unable to do so.