16v idling.

1. Nathan-HxC Established Member Joined: Aug 2010 Bath, South West Posts: 1081 16v VTR

   #1 27th April 2012, 19:31

   Hi all, my car is idling rough, as if it's cammed almost.
   It sounds really spluttery and pops on it's own whilst idling, also sometimes if I'm driving and when I come to a halt the revs dip to 500 rpm, shoot to 1500 rpm, then settle to 1000 rpm again but still sounds like it's cammed from the exhaust.
   Occasionally it will just stall when dipping instead of picking back up.
   
   Any ideas?
2. DanTvts Established Member Joined: Mar 2011 Torbay Posts: 1285 Mauritius Vts, 206 Gti 180

   #2 27th April 2012, 19:48

   ICV? coolant temp sensor possibly? However when mine did this, the butterfly was just a bit sticky, took it off and cleaned it all up, lubricated the butterfly a bit and it was sweet after. Few things to try there anyway, prob take about half hour to check those.
3. Nathan-HxC Established Member Joined: Aug 2010 Bath, South West Posts: 1081 16v VTR

   #3 30th April 2012, 18:55

   BUMP.
   I've had the ICV cleaned and had the MAP sensor replaced in relevance to a diagnostics test and it's still idling like it is.
   The bloke at the garage said that his old 106 GTI used to hunt for an idle but never as bad as mine, he says it's almost as if mine's cammed.
   It pops on idling and sounds really lumpy, like it's running rich.
   Any other ideas guys?
4. kirk Infrequent Poster Joined: Jul 2011 Posts: 183

   #4 30th April 2012, 19:25

   Could be the throttle position sensor?
5. Nathan-HxC Established Member Joined: Aug 2010 Bath, South West Posts: 1081 16v VTR

   #5 30th April 2012, 19:46

   Quote:

   Originally Posted by kirk Could be the throttle position sensor?

   Anyway of testing this?
   
   When the ICV was cleaned and the MAP sensor changed, the car was idling at about 1500 rpm for a while, then after a bit of driving dropped back down to 1000 rpm and idling lumpy.
6. DanTvts Established Member Joined: Mar 2011 Torbay Posts: 1285 Mauritius Vts, 206 Gti 180

   #6 30th April 2012, 20:53

   What condition are the plugs in? If its running rich could be the coolant temp sensor playing up (fairly common), or lambda sensor?
7. Nathan-HxC Established Member Joined: Aug 2010 Bath, South West Posts: 1081 16v VTR

   #7 30th April 2012, 21:07

   But surely if the sensors were shot then they'd of come up on the diagnostics test?
   Car was serviced about 3k miles ago.
8. DanTvts Established Member Joined: Mar 2011 Torbay Posts: 1285 Mauritius Vts, 206 Gti 180

   #8 1st May 2012, 00:21

   Yeah lambda probably would have but the temp sensors sometimes dont, or they just randomly start playing up, either way they're cheap so i'd try it regardless.
9. user_34090 Established Member Joined: May 2009 Devizes Posts: 2280 Blue Clio 172 Cup

   #9 1st May 2012, 14:00

   Mine sounds cammed at times then idle shoots up, cleaned throttle body and all that, no difference. Coil pack or something ?