Immediately after the recent cold snap, my engine starting running rough on idle and missing. Garage diagnosed coil packs and changed them, to no avail other than misfire and diagnostic now didn't report misfire issue. Engine still intermittently on idle running rough. no acceleration and hesitation for a few second and then fine. No timing chain thump or noise, 77,000 miles from new. Just thinking if some other electronic component could be it or whether i need to change the fuel filter if the car has one. Does anyone know where the fuel filter is located. Some people are saying its the timing chain... I do not have any timing chain noise coming from the engine at revs or at idle.
I do hear an occasionally thump like a flap at the opposite end of the top engine bay, like a flap occasionally flapping, as well.
Its a pulsar 1.2 petrol auto - Any help would be appreciated.
Thanks
Shaz
