UK-POLOS.NET - THE VW Polo Forum

Hi,

My Polo 1.4 (gasoline) runs rough at idle when warm.

I've done a compression test, nothing wrong there.
Done injector leak off test, all four good.
Tested all four coils and changed spark plugs.
Cleaned the map sensor & throttle body.
Checked for vacuum leaks, no leaks.
No fault codes on my obd2 unit, no fault lights in dash.

What can it be
a sensor maybe

I have the same problem, did you manage to get to the bottom of it?????

I have the exact same polo with the exact same problem, I've changed spark plugs and going to check my ignition coils soon but so far no luck

I've heard many say the polo just runs rough by nature but I still don’t like the rough idle, I've read somewhere it could possibly be a badly seated pcv valve but I didn't do much research into that, maybe look into it?

Same issues with 1.6 2007 model.
Starts fine when cold. I'll take a short journey to the shop for example and then start it again and revs a couple a hundred revs above usual idle speed and power delivery is sluggish for a few minutes.

Been told from other sources it could be a coolant temp sensor but wouldn't that show up on a code reader?