any ideas about my boost problem

[xTSIx]

For awhile now i have been having problems with my t-25. It used to boost 16 psi and then it slowly started dropping. It was at 2 psi for like 2 months and then this morning i put on a new wastegate actuator and it now boosts 6 psi. If i dissconnect the line to the actuator it will boost 15-16 psi, but only 6 psi when its connected. Does anybody have an idea. I'd appreciate input. thanks

 

[crashed97tsi]

Did you check for play in the compressor wheel? Do you have an MBC or the stock boost control solenoid? Also, maybe try a boost leak test and make sure that there are no leaks or anything in your intake tract.

 

[xTSIx]

i already did a leak test and there are no leaks. What compressor wheel?

 

[crashed97tsi]

ok, take off your intake and reach into the compressor housing. Grab the compressor wheel by the nut that holds the wheel onto the shaft and gently try and move it in every direction. There should be no or VERY little side to side or front to back movement. If there is any significant movement your turbo is going bad and you should consider buying a new one. Also try and look in there and see if the compressor wheel is in good shape (IE, no bent fins, nicks, etc.). You might want to wait until the car is reasonably cool before doing this, otherwise the turbo is very hot and you'll burn your fingers when you try and grab that nut.

Edit: when I say compressor wheel I mean the compressor wheel inside the turbo

 

[oldman]

Since you didn't answer whether you have a mbc or factory bcs I'm going to assume your profile is updated and you still have the bcs hooked up, have you tried bypassing the bcs and run the pressure source directly to the actuator? If so, what was the result? If not, try it.

i already did a leak test and there are no leaks.

How much psi was the system holding and for how long before you decided it was completed? From reading your original post, I suspect you have boost leak.