I have been boosting to 1bar for a few months now without problem. This morning one of my couplers popped off so I put it back on. Now I can't boost above 2 psi. It starts to build boost normally until it hits 2 psi then it just holds it there. I must have a leak somewhere. I have seen a couple topics on boost leaks but most of them point to couplers ripped or popped off. I tightened all my couplers and looked for tears/cracks but I did not find anything wrong. I checked the vacume hoses to the WG and they look good. I saw a thread on how to use a compressor to presurize the charge pipes. I will do that this weekend but I am looking for some other hints. It is weird b/c I do build some boost but only a couple PSI.

Any suggestions?

 

Strange thing is that the SSQV blows off a little when I let off the gas @ 2 psi like it normally would. Maybe the vaccum hose to the bov got messed up when the pipe blew off.

I hit about 10 psi when pipe blew the charge pipe off the IM.

 

^^^^^^^^

 

^^^^help^^^^

 

I'd do like you said and try to pressurize the charge piping to check for other leaks. If it checks out OK, then check to make sure your wastegate isn't stuck open.

You could have overspun the turbo when the charge pipe blew off as well. I'd check for excessive shaftplay, oil in the compressor, etc..

 

I hope it is not the turbo, but I will check. It holds pretty steady at about 3psi. Would that be more indicative of a boost leak or a turbo or exhaust manifold.

 

I just checked the turbo and it is fine...whew... But I do think I found the problem. I am using a flexible (and thin walled) aluminum tubing for the intake plumbing from the filter to the turbo inlet. The part next to the turbo inlet had completely collapsed by the suction. That may have restricted the intake enough not to build boost. I am going to test it out without the intake and see if that was indeed the problem.

 

sounds like a boost leak. Build the pressure tester and pressurize your system. Leaks can be a bitch to find. Your couplers may look good but that doesnt mean they are.

My boost leak was on the seam of one of my couplers. It didnt even bubble. I only found it by making the pressure tester and running my hands around all the couplers. Woulda never thought it would leak from there... just goes to show ya

 

Wow. A leak around the seam caused you to boost leak? How much boost were you able to build.

I'll give the pressure test a stab if I find out it was not my intake plumbing.

 

Sound like boost leak to me yo

 

I just took her out and it was the collapsed intake. I was using this crappy flexible alluminum hose to snake the filter around the engine bay. It had totaly caved in around the turbo inlet. Once I took off the intake it boosted just fine. Since I have the intake off I am going to compare datalogs to see if the colder placement of the filter ended up helping IATs at all.