How to find a Vacuum Leak - MustangForums.com

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How to find a Vacuum Leak

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Old 03-09-2007, 11:48 PM
  #1  
Zanador
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Default How to find a Vacuum Leak

Well, I have been chasing down this PO171 and P0174 codes for quite a while now. I am sure I have a vacuum leak, and that this could be a problem. When the car is on, there is a high pitched wistling near the tube to the IAC, under which the EGR vacuums are. I have been over the entire area time and time again, and simply cannot find this leak. Any ideas on how to find a vacuum leak in a car?
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Old 03-09-2007, 11:56 PM
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sprostang
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Default RE: How to find a Vacuum Leak

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Old 03-10-2007, 12:07 AM
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BleedinBlue
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Default RE: How to find a Vacuum Leak

ORIGINAL: sprostang

Bwahahaa....

Zanador, good luck. Not long after I got my car it started running rough at idle, blah, blah...you know what its doing. I couldn't figure it out for a long time, then one day it got bad enough that I could hear the hissing noise and I was able to pinpoint it.

Really, all I know you can do is listen and go over the tubes over and over again.
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Old 03-10-2007, 12:09 AM
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blackbetty01
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Default RE: How to find a Vacuum Leak

Turn the car on and let it idle, then spray WD-40, or some other type of high octane aerosol spray inlimited areas. Once the engine revs a slight bit you will have a better idea of where the leak is.

Edit- I really need to learn how to type.
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Old 03-10-2007, 12:46 AM
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Zanador
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Default RE: How to find a Vacuum Leak

Bleedin, thats the same exact thing that happened to mine. Bought it, and when it got cold it started idling rough. Soon after it started throwing these lean codes. Changed the IAC, went over the entire intake, new TPS, etc etc. Finally started noticing the hissing noise, and thats when I knew it was vacuum. I will definatly try that WD-40 trick, thanks!
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Old 03-10-2007, 12:51 AM
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iowanine
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Default RE: How to find a Vacuum Leak

Do it the good old way of squeezing. If you find one that isnot as "hard" as the othervacuum lines, then that is the one withthe leak. That's how I found mine.
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Old 03-11-2007, 12:38 AM
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Default RE: How to find a Vacuum Leak

I would use some carb cleaner and start spraying in all the critical area and wherever you spray and the engine chokes and sputters, you've found your leak. This method is similar to using the wd40 , but the wd40 will get your engine bay all oily...
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Old 03-11-2007, 01:31 AM
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Zanador
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Default RE: How to find a Vacuum Leak

Anyone know a site that has pictures of all the Vacuum lines? I have a vacuum diagram and have been tracing everyone I know of, but want to make sure I am not missing any.
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