Turbo half boosting!?!?

[SydCrazi]

Hi guys, 

 

Just wanted to see ideas before going to tuner. G6E. Car runs around 21psi. Wastegate spring 12-13psi. Car now won't boost past 13psi? Could it be wastegate? Or failed turbo? 

 

Would a failing turbo consistently only go to a certain boost? Or would it be different, what things am I looking for, just trying to determine which I think it might be? 

 

Thanks! 

[k31th]

well that much boost won't be a failed turbocharger itself...

 

try connecting the turbo front-nipple to the wastegate directly and see how much boost you get (it should be around what the rated pressure of the wastegate is) and then clean the boost control solenoid and re-connect it the correct way and try again.

 

if it still doesn't make the right amount of boost, either the electronics are not supplying hte solenoid with the information it needs to control it to that level or you have a boost leak.

[SydCrazi]

Thanks!! Where is the boost solenoid? I'll get under car and see if I can move actuator as well. I'm guessing boost leaks need some sort of pro test,, any place that does a pressure check at good price in Hawksbury or Hills area Sydney?

[k31th]

any workshop with an air compressor will be able to pressure test the actuator, so basically wherever you want to take it.

 

the boost control solenoid is down next to the battery. follow the piping from either the actuator nipple or the nipple on the front housing of the turbocharger and you'll find it easy enough.

[SydCrazi]

Well thanks again. ** Update **

 

I cleaned out boost solenoid. Still same problem. So either boost leak, but I can't find it, as all pipes seem good,,, or the wastegate is stuck open at 13 psi.. Turbo sounds normal, it has solid boost until 13psi then sits on that and the car feels weak as hell after that,, revs continue rising,, boost does not...

 

I might try the connecting turbo front nipple direct to wastegate,,,  is this a fancy way of saying bypass solenoid?? This will rule out solenoid completely I suppose.

[SydCrazi]

** Final update **

 

Found the problem. Cracked piping from intercooler cold ❄ side. Will replace piping with Plazmaman or Process West.

 

Will it need a re-tune with just piping replaced?? 

[k31th]

yes, that's a way to bypass the solenoid and run boost as slow as it can ramp up to the wastegate rating.

 

ahh yes... cracked piping. if the piping pathway is the same, then you'll be fine to just replace it without a tune.