03 WRX only hitting 5lbs of boost/CEL
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This is a discussion on 03 WRX only hitting 5lbs of boost/CEL within the General Maintenance, Troubleshooting & Accidents. forums, part of the Tech & Modifying & General Repairs category; I recently purchased an 03 WRX. The car only hits 5lbs of boost. I've tried several driving styles and nothing ...

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    Registered User WhiteRabbit1021's Avatar
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    Exclamation 03 WRX only hitting 5lbs of boost/CEL

    I recently purchased an 03 WRX. The car only hits 5lbs of boost. I've tried several driving styles and nothing is changing. (ie. letting the turbo spool before giving more gas and such). I checked all the lines I could see and they are all tight. However, the line off of the compressor housing has no restrictor pill in it, is this my problem?


    I'm guessing the car was modified and put back to stock before I bought it. When the turbo spools the gauge goes to .05 then slightly goes back down and sits. The needle sweeps very quickly up and down.



    Also, while driving the car home a CEL came on. The car has what I believe is a stock exhaust and some crappy orange intake. I'm hoping the ecu is set to stock right now but I have no idea. Is the intake what set it off? Also, the purge valve is very loud, almost sounds like a BOV... is the intake causing this too or is this a possible boost leak?

    I pulled the code and it was something along the lines of "exhaust temperature is too hot".

    I'm new to Subarus, and I used the search but failed to find a direct answer to my problem. Please help!
    Last edited by WhiteRabbit1021; 06-06-2008 at 01:44 AM. Reason: Engrish
    '03 DubRex

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    7 Pounds Of Boost

    I signed on to forum to find out the answer to the lack of boost. my 2002 wrx with 112,000 mi has lost a little power and i noticed the boost is at 7 max. The car runs fine smooth and the only thing i notice on top of this is a slight rough idle.

    Lee

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    Moderator Donkey's Avatar
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    Quote Originally Posted by WhiteRabbit1021 View Post
    I recently purchased an 03 WRX. The car only hits 5lbs of boost. I've tried several driving styles and nothing is changing. (ie. letting the turbo spool before giving more gas and such). I checked all the lines I could see and they are all tight. However, the line off of the compressor housing has no restrictor pill in it, is this my problem?


    I'm guessing the car was modified and put back to stock before I bought it. When the turbo spools the gauge goes to .05 then slightly goes back down and sits. The needle sweeps very quickly up and down.



    Also, while driving the car home a CEL came on. The car has what I believe is a stock exhaust and some crappy orange intake. I'm hoping the ecu is set to stock right now but I have no idea. Is the intake what set it off? Also, the purge valve is very loud, almost sounds like a BOV... is the intake causing this too or is this a possible boost leak?

    I pulled the code and it was something along the lines of "exhaust temperature is too hot".

    I'm new to Subarus, and I used the search but failed to find a direct answer to my problem. Please help!
    What is the actual code #?That is for the EGT probe.Also sound like you have the stock boost gauge.The measurements for that gauge are not psi,they are Mpa How To Read A Boost Gauge?

    Your hitting 7.25 psi.Yes it sounds like the missing pill is one of your problems.
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    Moderator Donkey's Avatar
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    Quote Originally Posted by LSOLO62430 View Post
    I signed on to forum to find out the answer to the lack of boost. my 2002 wrx with 112,000 mi has lost a little power and i noticed the boost is at 7 max. The car runs fine smooth and the only thing i notice on top of this is a slight rough idle.

    Lee
    The infomation you gave lacks detail.So are you saying since you have had the car it only boosts to 7psi or one day your out driving and all of a sudden your only boosting 7psi?Big difference.Most boxers do have a rough idle.When did you change the sparkplugs last?Also it helps when you list the mods done to the car.Certain mods cause certain problems.
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    Registered User adizzle02's Avatar
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    Quote Originally Posted by LSOLO62430 View Post
    I signed on to forum to find out the answer to the lack of boost. my 2002 wrx with 112,000 mi has lost a little power and i noticed the boost is at 7 max. The car runs fine smooth and the only thing i notice on top of this is a slight rough idle.

    Lee
    My 02 had the exact same problem i was only getting 7psi. I replaced the stock boost control solenoid and it works like a champ now. You may also want to double check the vacuum hoses. Here is a link from cobb that will show you how everything should be hooked up. I would also double check to make sure you have a restrictor pill. You can get all new hoses with the pill for under $20 from the dealer... the link will show you where that is also CobbTuning.com - How Subaruís Factory Boost Control System Works

    I bought a used BCS for $20 off of nasioc classifieds it shouldn't be too hard to find one.
    VF39'd and Clark Tuned
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    Registered User WhiteRabbit1021's Avatar
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    Thanks guys, I'm going to the Scooby dealership Monday to get a new restrictor pill. I'll also ask them about a BCS. I'll update you on how things go.
    '03 DubRex

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    Registered User adizzle02's Avatar
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    Quote Originally Posted by WhiteRabbit1021 View Post
    Thanks guys, I'm going to the Scooby dealership Monday to get a new restrictor pill. I'll also ask them about a BCS. I'll update you on how things go.
    if you need a new bcs dont buy it from the dealer there are plenty of guys that have the stock one sitting around that you can pick up for a steal...check out a few of the for sale threads the stealership wants over $100 for a new one
    VF39'd and Clark Tuned
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    Registered User grocerygetter02's Avatar
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    anyone have a part number for the restrictor pill for a VF34?
    How far will you go? What's your limit?

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    Registered User grocerygetter02's Avatar
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    I had just got off the phone with a dealer and they had said that the hose that you get with the VF34 turbo usually gets thrown out because when they did swaps out for people on the WRX's that it was causing overboost and blowing up so they would just put the cars factory one back on and send it out to have it custom tuned.
    How far will you go? What's your limit?

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    more info on .7 lbs of boost

    I have the car since new and it has no mods it used to boost to 1.0 when new. My wife has been driving it to work highway for a couple of years and quite slow I might add almost embarassing It wouldnt surprised me if the turbo never got used (not sure if this is good or bad) Now that I got her a new car I have been driving it and I noticed a slight loss of power. This is when I noticed the .7 when bringing on turbo. I paid the dealer to do the service at 30,000 and 60,000 and 90,000 by neigborhood mechanic and plugs were changed It was not idleing as smooth as it used to so I brought to subaru dealer. They said wrong plugs and original pcv still on car which they were supposed to have changed twice this is another very long story Anyway at that time there was "oil in the turbo" They cleaned it out changed plugs and then last december drove to michigan and back 3,000 mi no problem, there is another 10,000 miles since then. I am pretty sure the boost was 1.0 in December but since then I have not been driving it. From the other threads and talking to new mechanic it may be vacuum leak I am crossing fingers thanks for the input so far.

    Lee

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    Quote Originally Posted by LSOLO62430 View Post
    I have the car since new and it has no mods it used to boost to 1.0 when new. My wife has been driving it to work highway for a couple of years and quite slow I might add almost embarassing It wouldnt surprised me if the turbo never got used (not sure if this is good or bad) Now that I got her a new car I have been driving it and I noticed a slight loss of power. This is when I noticed the .7 when bringing on turbo. I paid the dealer to do the service at 30,000 and 60,000 and 90,000 by neigborhood mechanic and plugs were changed It was not idleing as smooth as it used to so I brought to subaru dealer. They said wrong plugs and original pcv still on car which they were supposed to have changed twice this is another very long story Anyway at that time there was "oil in the turbo" They cleaned it out changed plugs and then last december drove to michigan and back 3,000 mi no problem, there is another 10,000 miles since then. I am pretty sure the boost was 1.0 in December but since then I have not been driving it. From the other threads and talking to new mechanic it may be vacuum leak I am crossing fingers thanks for the input so far.

    Lee
    Generally a vacuum leak will get a CEL/DTC (P0457).You will only see max boost on a stock wrx in 4th and 5th gear.First and second gear is usually 7-8psi,third gear 10psi and 13.5psi for the last two gears.Subaru tuned for max boost in fourth or fifth gear.Blowby from the PCV system can gum up the BCS.Try cleaning it with some electronics cleaner (some people have used non-chlorinaded brake cleaner).Just do one port at a time so you don't mix up the vac lines.You don't need to spray alot.
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    Boost Fluid Resevoir

    I have read about how (low boost fluid?) could be causing the problem. How do you check that? What kind of fluid is used and how do you pour it in?

    Lee

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    I also am having a similar and sporatic problem like this. Im new to turbos and WRXs but im tryin to troubleshoot this. My car will only boost 11.5psi at its best, but then occasionally and randomly it wont spool up past 6psi, and then the problem will correct itself after some downtime and it will go up to 11.5 again. Its never coded anything out about this and i have no mods except for a turbo timer. One question i couldnt find an answer too is what kind of vaccuum would an '02 WRX see (at idle)? If im idling at a stop it will vaccuum around neg 10 psi, or if im coasting at idle it will vaccuum around neg 6psi. Ive heard that the vaccuum is supposed to be around neg 14psi at idle, is this true? If so then my rex is losing 2lbs of positive and negative pressure constantly somewhere in the system?

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    Registered User teflon_jones's Avatar
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    Quote Originally Posted by LSOLO62430 View Post
    I have read about how (low boost fluid?) could be causing the problem. How do you check that? What kind of fluid is used and how do you pour it in?

    Lee
    Boost fluid?

    Where did you read about boost fluid? Wherever that was, never read there AGAIN!
    Scott
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    I thought it was a joke. I am glad you had a laugh.

    Lee

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