How to find a Vacuum Leak - MustangForums.com


4.6L (1996-2004 Modular) Mustang Technical discussions on 1996-2004 4.6 Liter Modular Motors (2V and 4V) within.

Reply
 
 
 
Thread Tools Search this Thread
Old 03-09-2007, 11:48 PM   #1  
Zanador
2nd Gear Member
Thread Starter
 
Join Date: Nov 2006
Location: Bergen County, New Jersey
Posts: 477
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?
Zanador is offline   Reply With Quote
Old 03-09-2007, 11:56 PM   #2  
sprostang
I ♥ Acer
 
Join Date: Sep 2005
Location: Illinois
Posts: 6,190
Default RE: How to find a Vacuum Leak

sprostang is offline   Reply With Quote
Old 03-10-2007, 12:07 AM   #3  
BleedinBlue
5th Gear Member
 
BleedinBlue's Avatar
 
Join Date: Jun 2006
Location: Eureka, Mo
Posts: 4,355
Default RE: How to find a Vacuum Leak

Quote:
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.
BleedinBlue is offline   Reply With Quote
Old 03-10-2007, 12:09 AM   #4  
blackbetty01
4th Gear Member
 
Join Date: Nov 2005
Location: Central FL
Posts: 1,271
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.
blackbetty01 is offline   Reply With Quote
Old 03-10-2007, 12:46 AM   #5  
Zanador
2nd Gear Member
Thread Starter
 
Join Date: Nov 2006
Location: Bergen County, New Jersey
Posts: 477
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!
Zanador is offline   Reply With Quote
Old 03-10-2007, 12:51 AM   #6  
iowanine
3rd Gear Member
 
Join Date: Nov 2006
Location: Texas
Posts: 944
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.
iowanine is offline   Reply With Quote
Old 03-11-2007, 12:38 AM   #7  
calvinator
 
Join Date: Mar 2007
Posts: 2
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...
calvinator is offline   Reply With Quote
Old 03-11-2007, 01:31 AM   #8  
Zanador
2nd Gear Member
Thread Starter
 
Join Date: Nov 2006
Location: Bergen County, New Jersey
Posts: 477
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.
Zanador is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
OBD: The Adventure Begins (PO402 and PO401), DPFE/EGR test procedures TfcCDR V6 (1994-2004) Mustangs 1 09-14-2015 12:08 PM
01 Mustang Overheating :( MusicCity615 General Tech 7 09-12-2015 07:05 AM
Pinion angle, poly bushings, 1 piece DS mtgldr S197 Handling Section 1 09-10-2015 09:43 PM
need a water pump step by step guide needhelpplease 2005-2014 Mustangs 7 09-04-2015 09:59 AM


Tags
1996, 46, car, find, finding, ford, leak, modular, mustang, mustangt, vacuum

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Advertising
Featured Sponsors
Vendor Directory

All times are GMT -5. The time now is 03:50 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.