This is a general guide only and I will not be responsible for any damage you cause your vehicle or your face for that matter . I'm not a certified or expert mechanic. Perform this at your own risk and realize that over pressurizing your system could damage seals in your car. You will also be dealing with pressurize air, enough of it can turn objects into bullets, so make sure you secure everything.

This helped me track down my boost leak and I figure I'd pass the information over to anyone that may want to do the same. This is done with a very short and cheap shopping list from Home Depot. The only caveat to that is that you need an air compressor.

Pictured below are the items you'll need to put this together.



Air compressor male coupler
Teflon tape
Pipe end fitting with thread for the end cap
End cap
Drill bit
Spray bottle with water and dish soap


Picture of the end fitting for size and barcode number



Picture of end cap.



Instructions:

1. Wrap the tread on the end cap with teflon tape to seal it good. About 3 wraps around the threads should do.
2. Screw the end cap to the end fitting until it's flush together.
3. Drill a hole on the top center of the end cap for the quick coupler nipple. Depending on the size of male coupler you have, use the same size drill bit. You do not want to open the hole up too big or you'll have nothing to screw on to.
4. Wrap the thread on the male coupler with teflon - again about 3 wraps.
5. Screw on to the hole you drilled



End product




How to test
1. Unclamp your air intake hose from your intake box/filter. It's probably good to remove the air box but you should be able to move the intake hose enough for the next step.
2. Mount your quality home depot tester to your intake hose and clamp down.
3. Set your air compressor regulator to 5psi. I found that the green gasket in the supercharger inlet tends to leak after 5psi, which makes it hard to listen to the boost leaks you're really after. DO NOT OVER PRESSURIZE AS YOU MIGHT START BLOWING SEALS. Keep it regulated at 5psi.
4. Let the pressure build at around 5psi and start listening for a hissing sound. If it's coming from the front the car, it's likely your green gasket, which you can ignore. Listen for it in your vacuum hoses, intercooler, boost gauge line, etc.
5. If you can't identify the exact source, use the bottle of water and soap and spray in the area. The leaking air will form bubbles.




I was able to find a couple of leaks in my car with this method. I was originally only boosting around 9psi, but after fixing my leaks, my car is now at a healthy 13psi.

Good luck and happy hunting!


Note: I tested with both the bypass valve open and shut. Some of the experts might be able to chime in on what's the ideal way to test or if it even matters. I opened mine so that the air could easily pass through but it may not be necessary.

 

Nice writeup! Does this method detect faulty BPV's also? Just curious cause i would assume the BPV is a normally open valve.

 

In terms of whether your BPV is not closing properly, no. More or less for finding leaks in your vacuum lines or IC boots.

 

I figured so, ill try this out this weekend, seams more practical than soaking the motor with soap and water.

 

the BPV is closed when the engine is off, and opens as the engine starts. while the engine is at idle, the BPV is open, allowing the "boost" to be "bypassed" so you dont blow through gas at red lights.

 

Thanks for the great write up! I rigged it up and found a little leak at the oil catch can.

I'm in the Longmont/Boulder area if anyone wants to borrow it.

 

this is awesome! i dont think i have any leaks but i wanna try this just for kicks

 

To bad the pictures don't work anymore

 

heres mine, its a 2in cap and coupler that i epoxied together. the ouside diameter is just shy of 2.5 in. remember to block off the breather and pcv lines. I was able to find my gasket leak between intake duct and supercharger right away. Also i only added 5 psi to be on the safe side.