Hi guys! I need of some help here... ive got an A4 S-line FSI Quattro 2.0t petrol and just recently the tickover is terrible.. when im sat in neutral the revs bounce up to 2-3k and back down sometimes to the normal tickover range but sometimes nearly stalling. It just continuously does this at any temp. any ideas?? 

Hi Myles...welcome to the Forum

Sounds like it could be a vacuum leak...check all the rubber hoses under the bonnet for splits or even hanging off.

Let us know how you get on

Cheers  Trevor

Hi trev. Thanks for your reply.. finally got a chance to take a look.. all hoses seem fine.. i was checking around the top of the engine and started playing around with this round plastic looking thing on the right hilighted in orange (no idea what it is) and it seemed to alter the revs sometimes making it worse and sometimes making it tickover perfect. I then took the pipe off the top of it and put my thumb over the end and it ran mint.

Shall i try and change this see if it works if so what is it called? 

Thanks.

I thinks that's the PCV valve your referring to funny enough I just changed mines. I made a thread. 

Also in the past with my golf mk 4 every couple of years I'd get random reving like yours in eight years ownership I had to change the AIR MASS SENSOR twice. 

Hi Ric, ill take a look at that thread. Ive got the valve on order and will replace it soon as. If the problem is still there ill try the air mass sensor.

Thanks for your advice 👍👍

 

Hi guys.. managed to get a pcv valve sharpish.. changed it with ease and its worked! 

Thanks for sharing your knowledge and helping me out. Much appreciated.