Major loss of boost ?

[Twinturbo2800]

ok ive been riding around boostin adn whatnot, but recently i decided to look at my boost gauge while flooring it to see how the cold weather effected the turbo..

to my surprise its boosting 5psi LOWER then it should. (ihave it set for 15-16lbs)

and its going to 9-10, still seems like its the same speed wise.

any ideas? i have white smoke out the exhaust also...

 

[TooFastTooG]

Well the first answer your going to get is do a boost leak test.

But if your saying your car feels the same, check all the conections of the boost gauge FIRST, then let us know.

 

[Twinturbo2800]

i really dont hear any leaks, gauge is set up fine, what could this possibly be??

could it be anything related to me be iver due for an oil change? im 2k over

(i know, thats bad, im always right on time.

 

[TooFastTooG]

This has been said time and time again, you need to do a boost leak test, not all leaks are going to be able to be heard just from you driving it. Hell, some leaks you cant even hear when your doing the boost leak test and have your ears right up to the engine. But spray on some soapy water, and what do you know you can see bubbles, and that means LEAKS.

 

[oldman]

1. Turn the ignition to "on" position, make sure the gauge zeros out. Checks out, goto 2.

2. Check for pre-turbo exhaust leaks. No leaks, goto 3.

3. Test run with the actuator nipple open, feather the throttle as infinite boost is expected. If boost shoots past 10psi, you have a defective mbc. BTW, if your TurboXS mbc is the standard bleeder version, make sure you tap the compressor/J-pipe for pressure source instead of the BOV line. If you're still only boosting 10 psi, goto 4.

4. Pressure test the intake tract and fix all leaks, if problem persists after this, you most likely have a problem turbo.

Good luck.