Poor idle only when at full temperature

1. xpeterpx Regular Poster Joined: Jul 2011 Posts: 420

   #1 27th February 2012, 15:13

   New ICV time me thinks but I have cleaned the ICV (really well) and all aroung the TB area.Made a slight difference for a while but its back to the old bouncing revs again..
   
   Before I splash out wanted to point out that it only idles poorly when the engine is at the full operating temperature.If it was an air/vacuum leak would it cause poor idling at startup too?
   
   Am I right in thinking its deffo the ICV now?
   
   Thanks
2. Ben_SaxoForte Saxperience Forum Bum Joined: Mar 2009 Stoke-on-trent Posts: 2640 Mk5 Golf GTTDI Mk2 VTR Project

   #2 27th February 2012, 17:19

   coolant temp sensor?
3. xpeterpx Regular Poster Joined: Jul 2011 Posts: 420

   #3 27th February 2012, 21:25

   Cheers Ben..
   
   On a 99 plate SX I think there are two sensors bolted to the side of the block-is it the blue plug or green does anyone know?
   
   Cheers again
4. horey Newbie Joined: Dec 2011 Spalding Lincolnshire Posts: 14 Mk2 saxo vtr two tone Mk2 saxo 1.1i in black

   #4 28th February 2012, 08:46

   mine has got a similar problem with hunting at idle and it turned out to be a air leak just between throttle body and manifold but it too is fine on start up just when it gets hot but you can here mine taking the air in like a hissing noise
5. xpeterpx Regular Poster Joined: Jul 2011 Posts: 420

   #5 28th February 2012, 10:38

   Apart from physically checking pipes or splits and connection etc -Best way to detect air leaks in the engine bay anyone?
6. horey Newbie Joined: Dec 2011 Spalding Lincolnshire Posts: 14 Mk2 saxo vtr two tone Mk2 saxo 1.1i in black

   #6 28th February 2012, 11:53

   well what i did is sprayed wd40 over the throttle bodie and intake system then washed it off with water while the car was running then it bubbles and hisses where the leak is and then you know where it is llike when you look for a puncture in a bike tyre same thing really i found this to be the quickest way cuz then you dont have to check all the pipes seperatly and youl acctually see the leak
7. Manu Saxperience Addict Joined: Dec 2009 Posts: 11714 A6 Le Mans tuned/A3 TFSI tuned

   #7 28th February 2012, 12:05

   you don't have one of them cheap / nasty mushroom air cones have you? They tend to heatsoak. Just a wild guess.
8. xpeterpx Regular Poster Joined: Jul 2011 Posts: 420

   #8 28th February 2012, 12:09

   Quote:

   Originally Posted by Manu you don't have one of them cheap / nasty mushroom air cones have you? They tend to heatsoak. Just a wild guess.

   Good idea but no.just a standard airbox setup.