ashwinearl Posted May 28, 2020 Share Posted May 28, 2020 I have a 2005 Legacy GT wagon. On clutching in, there is that feeling of rpms dropping low towards a stall sometimes. It hasn't stalled yet. I mentioned it to the E-tuner and he said it could be the blow off valve. This is the stock BOV. Is it worth getting a new stock BOV as a diagnostic step? I have no interest in an aftermarket BOV. Thanks Link to comment Share on other sites More sharing options...
whitetiger Posted May 28, 2020 Share Posted May 28, 2020 id check to see if your return tube is in good condition. if it leaks to the atmosphere, metered air is escaping and it could cause the exact issue you are talking able. Link to comment Share on other sites More sharing options...
Keyan Posted May 28, 2020 Share Posted May 28, 2020 a failed stock bov will not cause a stall it will cause lack of boost. Link to comment Share on other sites More sharing options...
whitetiger Posted May 28, 2020 Share Posted May 28, 2020 a failed stock bov will not cause a stall it will cause lack of boost. unless it is stuck closed. you get full boost, but you also get compressor surge/stall. Link to comment Share on other sites More sharing options...
Max Capacity Posted May 28, 2020 Share Posted May 28, 2020 A vacuum/boost leak check may be the first step. Sometimes called a smoke test too. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
Keyan Posted May 28, 2020 Share Posted May 28, 2020 unless it is stuck closed. you get full boost, but you also get compressor surge/stall. compressor surge is not the same as an engine stall. a stuck closed bov will not cause the engine to stall. Link to comment Share on other sites More sharing options...
Pleides Posted May 28, 2020 Share Posted May 28, 2020 From my limited experience, the car will send a CEL if your BOV isn't working right, something along the lines of a cylinder running too lean. My car often nearly stalls when pushing the clutch in, however I have two culprits for it. One, the car needs a valve adjustment (think a motor out job - this is not easy and I'm waiting for the motor to blow up rather than paying someone to do this). It often will stall when you're creeping in traffic, and you'll just go "Wait, the hell? I barely let the clutch out?" Two, I've replaced my oil control valves with new parts and most of my stuttering/stalling issues went away briefly, only to come back a couple days later. Seems the culprit could be some gunk in the oil. Running Seafoam through the oil then changing it shortly after seems to help, but it does keep coming back. I've come to just accept that it is what it is. Hopefully that can give you a starting point. Have you done a valve cover gasket recently? That would be where you would check valve clearances. If they're super tight <.1 mm) then you're gonna have to accept that your car will stall sometimes. Idle will often be rough as well. Link to comment Share on other sites More sharing options...
ashwinearl Posted May 29, 2020 Author Share Posted May 29, 2020 I should have clarified. I've had this issue for a while. Recently, I went through an refresh where I kept the stock block as is and sent the heads off for refresh from a machine shop. We replaced all hoses, valve covers, clutch, flywheel, oil pan, pickup, gasket kit, timing...basically everything one goes through with YNANSB except for the shortblock part. I am never that close to a stall, it just has that feeling, and think that it shouldn't be like that. When it was going back together, there were several leaks that were found, and had the requisite hoses blowing off, but everything seems pretty good now. I went through an Etune process, and once we found some of the initial leaks and changed my MAF back to the OEM one for the model year car, the tuner didn't see anything out of the ordinary. For kicks I might look for an OEM BOV and just try replacing it. Link to comment Share on other sites More sharing options...
whitetiger Posted May 29, 2020 Share Posted May 29, 2020 compressor surge is not the same as an engine stall. a stuck closed bov will not cause the engine to stall. compressor stall, not engine stall. :facepalm: Link to comment Share on other sites More sharing options...
Holla Posted May 29, 2020 Share Posted May 29, 2020 My car often nearly stalls when pushing the clutch in, Do you have a light weight flywheel? Link to comment Share on other sites More sharing options...
ashwinearl Posted May 30, 2020 Author Share Posted May 30, 2020 Not sure if this questions we directed at me, the original poster: I have a Lightweight pulley (Grimspeed) and just put in a stock WRX single mass flywheel with new stage 1 Exedy Clutch. Link to comment Share on other sites More sharing options...
kzr750r1 Posted June 2, 2020 Share Posted June 2, 2020 I have a spare stock BOV, if you would like me to ship it lets talk in PM. However, wanted to ask. How long has it been since changing the AVCS solenoids? Although I'm Auto had off idle stalls for a while until changing the solenoids. IMHO these should be replaced at each timing belt update interval. Fought it for 20K swapping parts including the BOV, that didn't fix it. Link to comment Share on other sites More sharing options...
ashwinearl Posted June 3, 2020 Author Share Posted June 3, 2020 (edited) I have a spare stock BOV, if you would like me to ship it lets talk in PM. However, wanted to ask. How long has it been since changing the AVCS solenoids? Although I'm Auto had off idle stalls for a while until changing the solenoids. IMHO these should be replaced at each timing belt update interval. Fought it for 20K swapping parts including the BOV, that didn't fix it. Hi, Are the OCVs the same thing as AVCS? If so, I had them changed at around 90k. I have 160k now. Edited June 3, 2020 by ashwinearl Link to comment Share on other sites More sharing options...
Holla Posted June 3, 2020 Share Posted June 3, 2020 Not sure if this questions we directed at me, the original poster: I have a Lightweight pulley (Grimspeed) and just put in a stock WRX single mass flywheel with new stage 1 Exedy Clutch. No, it was directed at the post I quoted. Less rotating mass means less inertia though which can lead to stalling issues when clutching in. It's possible the car is having trouble recovering the idle due to less inertia. My Honda used to die all the time. If I clutched in from 5k+ and let the RPM's drop, it would just die. This was due to the light weight flywheel though. I don't think the Grimmspeed pulley is that light, but it may be contributing to your issue. Link to comment Share on other sites More sharing options...
kzr750r1 Posted June 3, 2020 Share Posted June 3, 2020 Hi, Are the OCVs the same thing as AVCS? If so, I had them changed at around 90k. I have 160k now. Same animal. I just use the wrong acronym at times. Those should be ok for a while longer. I'm on a third set now at 230K. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now