Hi guys, my 2013 st(petrol) has developed a hesition/ surging around 2000-2400 rpm, more noticeable in 2nd, 3rd and 4th gears but still present in other gears aswell. Doesn't matter if car is hot or cold or what the weather temp is either but is more pronounced now with the colder weather and engine temp.

No fault codes stored but is becoming more regular when it plays up, recently had full service which made no difference, apart from a k&n panel filter that was in it when we brought it the car is completely standard.

 

Any common faults or fixes that you are aware of that could cause this issue.

 

Thanks Ian 

I had this a couple of winters ago with my 1.6 diesel. Hesitation and surging for a day or two then i lost all power and had an EML. 

Turns out the fuel filter needed changing - Evil Halshaw whom I'd bought it from told me they'd done it when they hadn't...