I hope it is simple to diagnose. When I start, it runs perfectly. Once I get to normal running temp. is when I start to have problems. The engine seems to run a little rougher, and when you press the gas from a idle speed just slightly, it jerks and shutters like a spaceship re-entering the earths atmosphere. Sometimes it takes about 20-30 minutes of driving before this starts to happen. Any idea what it could be and about how expensive to fix?

I have been told it could be at torque converter but I'm not sure if that's accurate.

 

Bump

 

Could be a bad coil pack