MBC on T25..high pitched noise

[paranoidTSi]

Well I finally got the MBC on my car after a hell of a 4 hour struggle to figure out how the hell to hook it up after the previous owner had a profec-i boost controller but took out the control module but left the box. Anywho I have successfully hooked it up now, but I've noticed the turbo makes quite the loud pitched noise now when I'm on WOT@ 15psi..is this normal?

I checked (actually today) for shaft play and there isn't ANY at ALL. Just wondering if anyone else has experienced this.

 

[PieEyedPiper]

possibly higher pitched due to boosting 15psi? stock is like 9-12.
just an idea.

 

[c5chris]

Your GAIN is set too high. Back it up a little and you should be ok.

 

[psychlow]

Boost leak Nazi, here.

If you haven't already, check for leaks.

Increasing boost to 15PSI with an MBC can sometimes make gaskets/seals pop that used to hold fine at 12PSI.

If you have no leaks, then you can attribute the increased noise to the turbo spinning faster to produce 15PSI, assuming there's no appreciable shaft play and it's not blowing smoke.

 

[c5chris]

A howling turbo without a boost controller might mean a turbo is near its last leg. Check for shaft play or the seals.

 

[punishercb]

He already checked for shaft play if you read his post.

 

[paranoidTSi]

I do believe it is the turbo, just wondering if anyone else experienced this? there doesn't seem to be any *OBVIOUS* leaks, Checked all IC pipes, etc. for leaks, the only thing not checked is the throttle body.

 

[Hammer_Gaidin]

I would recommend that the T25 not be set so high. You could kill your turbo...12 is better.... But it's your car. If you would like to run 15psi why not pick up a 14b for cheap...much better.

 

[psychlow]

I do believe it is the turbo, just wondering if anyone else experienced this? there doesn't seem to be any *OBVIOUS* leaks, Checked all IC pipes, etc. for leaks, the only thing not checked is the throttle body.

I can't tell you how many times I've heard this, only to have someone actually do a proper pressurized test and come back saying they found 5 or 6 leaks.

 

[Hammer_Gaidin]

I can't tell you how many times I've heard this, only to have someone actually do a proper pressurized test and come back saying they found 5 or 6 leaks.

Agreed

 

[dsmpride]

Do you have the pressure line to the mbc coming off of the nipple on the compressor housing of the t25? If not, do you have that capped off?

Kent