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Stock idle vacuum question

  #1  
Old 04-29-2011, 12:26 PM
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Default Stock idle vacuum question

I recently installed a boost gauge in my 1.8T. From what I understand, the vacuum should be somewhere around -20 when the car is idling. Mine seems to sit at about -11, when idling and even when cruising.

Does this indicate a a vacuum leak somewhere? I do seem to get close to the stock 7-8 psi when I'm WOT in 4-5 gear, but the fact that my idle seems low has me wondering...
 
  #2  
Old 04-29-2011, 02:20 PM
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Yeah 11 in. hg. is low at idle. Mine idles around 24 and when coasting in gear it sits at about 28 in hg. You might want to take a look at replacing some/all of your vac lines.
 
  #3  
Old 05-01-2011, 11:59 AM
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Yeah that seemed to be the issue. I was replacing my DV valve anyways so I went ahead and replaced all the small braided vac lines. After putting everything back together it holds at about -22 when idling and -25/-26 when cruising. Granted, I'm not sure how accurate a mechanical gauge is but does this seem better? Or I may still have a small leak somewhere?
 
  #4  
Old 05-01-2011, 12:39 PM
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Your idle is sitting right where you want it, good work.
 
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