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Old 02-26-2013, 09:44 PM   #17
Registered User
Join Date: Feb 2013
Location: Ohio
Posts: 69
My Ride: 325xi
Originally Posted by jonnie325xi View Post
I have a way of checking for vac leaks that has worked for me on 2 of my 325's, I take out the air filter box and MAF sensor,
Where the maf sensor attaches to that 3" rubber hose I stand to the side bend over and put my mouth to the 3" hose get a seal around my face and blow, you should be able to pressurize the system and listen for any leaks. if all is good you should be able to build up a pressure and hear no air leaks, I have found 2 bad vac lines to the fuel filter pressure regulator, torn intake boot, and cracked line to the valve cover.
You can hear the hissing right away if you have a problem, it helps if you have someone look and listen as you blow in and hold a slight pressure, It looks and sounds funny but it has worked great for me. no need for smoke testing.
This is really strange because I do not have a MAF because there is no "box", only a chrome pipe with a v shaped filter on the end of it. My car is a 2002 and I'm not sure if this is factory installed or an aftermarket thing. Does anyone know where the MAF is located in my case?

I'll take a pic and post it tomorrow when I can get into the garage.

Last edited by tomjohnson; 02-26-2013 at 09:53 PM.
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