Only Half The Boost

[aspenwrx]

My 02 Wrx Has Not Been Making Full Boost Since I Got It I Always Suspected That Their Was Somthing Wrong But All The Shops I Take It To Cant Find Anything Wrong. Everything Is All Good (smoke Test Came Back Good Turbo Is Capable Of Makeing 20 Psi No Leaks Wastgate Is Working Correctly. So Now Im Kinda Stuck So If Anyone Has Any Ideas I Would Greatly Appreciate It.
By The Way Cobb Ap Is Saying 8psi And Gauge Is Saying 10psi

[06wrx4me]

What gear are you in when checking boost? 3rd?

Is the factory restrictor pill in place?

Do you have the factory BCS?


If the above aren't the causes, then you may need to adjust the WG actuator rod.

Testes1010 can explain this better than I can.

[teflon_jones]

Punctuation and proper capitalization are your friends. You'll get a lot more help if you take two seconds to post something that's easy to read. If you don't, then most people won't take the time to answer you!

What mods does your car have? How many miles? Any recent changes?

[adizzle02]

my 02 was having the same problem but i was only getting 7psi. My problem turned out to be the stock boost solenoid. But as stated make sure to check and see if you have the restrictor pill.

[I_<3_JDM]

where is the restrictor pin located?

[adizzle02]

its in the little section of hose comming off the T fitting going to the turbo. You should be able to feel it if its there.

[I_<3_JDM]

in tha hose that goes from the wastegate to the turbo
which part would it be in??
wastegate side turbo side or the hose off of the T

[adizzle02]

Turbo side. Check out this cobb link it has a pic of which hose it should be in
CobbTuning.com - How Subaru’s Factory Boost Control System Works

[EJ257]

My guess would be the solenoid - see if you can get together with a local Subaru owner and borrow theirs for a few minutes. Do a few runs and see if that helps.

[morphine16]

Had/Have the same problem as you. I would run around half boost for long periods of times(consistent boost, never fluctuated.) and it would randomly started to work again. I got sick and tired of it doing this and took it into the dealership. They claimed i needed a new turbo and something else(cant remember what it was. Solenoid perhaps?). I went ahead getting the turbo. Only because Subaru payed for most of it.
The first month went smoothly with no problems, and then i experienced de ja vu. Same problem all over again. However it doesn't lose boost as frequent as before. It is really starting to bother me =(((((. I have to take it into subaru soon.

Also i have a problem, where at high rpms i hear a grinding noise! Almost sounds as if rocks were fluttering around in my engine. The subaru guy said that it was the ball barings in the turbo and one of them was cracked or something like that. Still have the same problem! So if anyone knows what that is please let me know! (sorry for hijacking, just letting you guys know my experience with this horrible/annoying problem)

P.S for some odd reason i normally lose boost under hard condiotns. Such as hard breaking, Uphill acceleration ect.
And its weird because ill get it back most of the time going up hill. Dont know if its me, but thats how it feels.

Any ideas?


Edit: guy at subaru said that a new turbo would fix the grinding noise, too bad it didn't