A few months back I cleaned the throttle body because of a code when checking with VagCom. Since then, more noticeable now it's cold, I have a slightly erratic idle. Not all the time but occasionaly, starting a warm/hot engine it will idle around the grand mark briefly then settle down. Temp gauge sits just above half the norm in this weather too. Suspect temp sender?

When you say ereatic idle, do you mean its bouncing around a bit?if so Unplug the maf. 

If it runs the same, its knackered, get a genuine replacement as the vw engines dont like aftermarket ones.

 

If you mean your cold idle is sitting a bit higher than "summer" and the temp gauge isnt showing higher than 70° (ish) then its most likely the CTS.

Hi and thanks for the reply. Wrong choice of word, erratic. I meant more unusual. 

"If you mean your cold idle is sitting a bit higher than "summer" and the temp gauge isn't showing higher than 70°", that sums it up nicely. Will get onto TPS for a new temp sensor.

Just a quick update, new CTS fitted and has made only a small difference to running temp. Now gets up to 80 degrees but still have the warm/hot start puzzle. On starting the engine will race up to 2000 RPM then drop down to idle.

Did you get a genuine cts?

When it drops back to idle, is it settling nicely at "normal" idle?

How long is it spending at 2k rpm?

Hi mac. 

Picked up CTS from TPS locally, identical to the one that came out, green top.

When it settles, down to normal RPM, around 700. High RPM lasts a second or so.

Do you touch the throttle when you start the car? ie give it some gas?

Hi octyal, nope.