Car : 53 307 2.0 Petrol So my car started to run erratic on idle for some time now but was not noticed in accelleration, until now. The car feels like it is jerking with power on/off all the way through the powerband. The engine is making a loud tappet noise , oil and coolant levels are good and run OBDII test highlighted no error codes . Help is really respected! Any suggestions people? I am starting to think it could be sparks? But wouldnt a problem show?