Just experienced a problem with my new Evo IX MR- After driving it for about an hour or so yesterday I noticed it made this whoosh sound at wide open throttle sometimes... not every time I accelerated, but almost every time. The sound was accompanied by my boost tapering off to under .5 bar really quickly and a huge loss in power. I tried accelerating hard a number of times and this whoosh and loss of boost would happen at random rpm levels, happen in all gears. At times I would be nearing redline and the car had been holding boost at the normal 1.3-1.4 bar just fine, for like a few seconds, and then it would make the sound and boost would fall below .5 bar (like in about a half second of time). I tightened the IC piping down that I could see and still the same problem after driving it again. Could this be the BOV getting stuck open or something or just a boost leak? The car has only 1100 miles on it and the MR's BOV is supposed to be pretty good, so it makes me think its a boost leak. Are the techs at the Mitsubishi dealership knowledgable enough to figure it out do you think? I'm taking it in later this week when I get time but was hoping for some insight from somebody here in the meantime... BTW, everything is stock under the hood, all I have is TBE on my car...
Couldnt find a thread where someone described boost leak sounding like this- any help is appreciated-

 

bump

is this my wastegate or BOV getting stuck open or a problem with my ECU?
I have 3" turboback exhaust installed (DP I wrapped in heat tape)... only thing I can think of is that my ECU is recognizing the increased air flow and earlier turbo spool due to the increased exhaust flow and sending a signal to the waste gate to stay open.... that or the waste gate is just getting stuck open... my car acted up ater putting just a drop in K&N filter in both before and after my exhaust was installed, so it makes me think it may be the ECU noticing the difference in air flow and cutting power like it would if I had a ram-air type intake or something... for now my car is running better and stronger with the stock filter over the K&N, which doesnt make sense unless the ECU is seeing too much air flow....I have the stock filter in for now, but still am experiencing this rapid loss in boost at WOT in the higher rpms... (?) Anybody have knowledge on the issue or experienced something similar to this prior to a reflash? I am assuming that a reflash will correct this unless of course it is my waste gate getting stuck open for some unknown reason, but I would really be surprised if that were the case- the car only has 1250 miles on it. Anyway, any insight is appreciated- thanks

 

try a boost leak test

 

i agree...try a boost leak test....

 

I have this problem too on my IX MR. its really random too.