Discussion Starter · #1 ·
Hello all. I have a ballooned stock intercooler on my 07 GXP. I have the GMPP mod, which may have contributed to this problem as I understand it, after reading many posts on this forum. I don't see any cracks, just the top tube ballooned from about the middle to the driver's side end. When I get on the throttle, 16 psi is highest boost that I am seeing, and I hear what sounds sort of like a pressure cooker relief valve doing it's thing..."psst psst psst psst" (it seems like its coming from somewhere on the passenger side). I'm thinking that the intercooler likely does have a crack. I've checked and tightened all the hose clamps from the turbo to the intake manifold. I'm not throwing any codes. Is there a possibility that the intercooler and associated tubes are tight (i.e., no leaks), and that the noise is coming from somewhere else? I don't know much about how the wastegate operates, but could it be the culprit? Should I be able to move the wastegate rod by hand when the car is not running? (I can't.) Anyway, I thought I'd ask. I know there are some pretty sharp cookies in this forum. I've thought of disconnecting the hoses on the inlet and outlet of the intercooler and pressurizing it to check for pressure drop, but haven't done that yet. I'm thinking that some of you experts out there might suggest that I go ahead and replace the intercooler. Another question...if I had a ballooned intercooler with no leaks anywhere, no weird sounds or anything, could a ballooned intercooler by itself cause me to only realize 16 psi maximum boost (with the GMPP mod)? Just wondering...if the answer is "yes", then I won't feel as bad about making the plunge and ordering a new one, even if I'm still not sure if mine has a split/crack/busted seam. I've been looking at my options if I were to go ahead and order a new one, any suggestions there? I don't think I want an OEM, as I've read of solder issues with some of them, and also of issues with them ballooning on cars with the GMPP mod. I see that I can get the HAHN for around $600, but what about the other aftermarket brands, JJWorks, etc? How do the performance and quality compare among the aftermarket intercoolers? And how installation friendly are they...how much might I have to cut on the car's framework for proper fit? Thanks for reading, and thanks in advance for any insight and advice you might share!