Boost leak test........not building boost

[gsxrtalon]

Hey guys, I just did a boost leak test today. I took the intake off the turbo and hooked up the tester and had a friend sit in the car to tell me when boost got to where it should of so I could start listening for leaks. My friend said the boost gauge only went to 0.5 on my blitz boost gauge(not sure how much that is, but not 23psi like im running) I am using a shop compressor at 100psi(can go more but didnt) The system just wouldnt build anymore boost. As it was at 0.5 I listened for leaks and didnt hear any besides from the hole on my joe p mbc, but that is normal Im told. Any suggestions why its not building boost to the levels im running daily? You are supposed to be able to test at the same PSI levels right? Thanks for the help guys.

 

[MadTripper]

Recommended that you either remove the MBC and run a line from the housing to the WG (if you set it up that way) or adjust your MBC to max pressure so it won't leak.

Additionally, you should only apply the amount of pressure you typically run or a few pounds over.


Tripper

 

[gsxrtalon]

thanks, I was not sure what lines to disconnect and switch. Yes, I heard that you are only supposed to take the pressure up to the boost levels you run. It is hard for me to do that because the boost gauge I have reads like this........0, 0.5, 1.0, 1.5, 2.0.........and I honestly dont know what either of those numbers are. I simply use my dsmlink to set my boost. Oh, my boost gauge is a Blitz.

 

[alex99gst]

Instead of listening for leaks, you can fill a spray bottle up with soapy water and spray them on all of the couplers and all the pipes.

 

[alex99gst]

You have a boost gauge that reads in bar, or barometric pressure. 1 bar is equal to 14.7psi

 

[gsxrtalon]

Thanks

 

[kenamond]

Might be a bad PCV valve. They can be hard to find. Pull the breather hose off your intake pipe (or valve cover) and repeat the test. If air is coming out of there like mad, pull the PCV valve out of the valve cover and repeat the test. If air is coming out of the PCV, it's bad. It's a 1-way valve that's supposed to only let air *out* of the head and back into the IM when you have negative gauge boost pressure (idle, or decelerating), so if air is coming from the IM and out through the PCV, it's bad and leaking boost pressure.

I had no luck with Autozone or Checker PCV valves; they both leaked just as bad right out of the box (checked the 2nd one in the store and saved myself $3 ). You need an OEM PCV valve that was designed to hold back boost pressures, or you need to cap the PCV hose on the PCV end (so boost can't leak out of the IM) and route the PCV outlet to a filter/catch can so that it can still vent. Getting a working PCV valve is the best option, though.

 

[gsxrtalon]

thanks I will try that.

 

[dalatinromeo]

Might be a bad PCV valve. They can be hard to find. Pull the breather hose off your intake pipe (or valve cover) and repeat the test. If air is coming out of there like mad, pull the PCV valve out of the valve cover and repeat the test. If air is coming out of the PCV, it's bad. It's a 1-way valve that's supposed to only let air *out* of the head and back into the IM when you have negative gauge boost pressure (idle, or decelerating), so if air is coming from the IM and out through the PCV, it's bad and leaking boost pressure.

I had no luck with Autozone or Checker PCV valves; they both leaked just as bad right out of the box (checked the 2nd one in the store and saved myself $3 ). You need an OEM PCV valve that was designed to hold back boost pressures, or you need to cap the PCV hose on the PCV end (so boost can't leak out of the IM) and route the PCV outlet to a filter/catch can so that it can still vent. Getting a working PCV valve is the best option, though.

I always wondered how to test a PCV vale to see if its good or not. Thanks.