rough idle, dipping revs, GFB bov

[MY05WAGON]

Hi guys
The guys with the GFB hybrid BOV's i'd thought i'd just let you know. I've had some slight rough idle issues recently, also when im about to stop at a traffic light etc the car would sometimes nearly stall. So first thing first i cleaned the AFM with some contact cleaner and adjusted the BOV setting a bit harder as i thought that could be leaking. Went for a long drive and it was pretty good for sometime. Then it started getting bad again DOHHHH! i read on the legacy gt forum that the GFB paper gaskets are pretty crap (which it is) so i took it off and had a look, upon inspection it look like part of the gasket didnt have any marks on it (sorry didn't take any photos) so perhaps it wasn't quite a snuggly fit and possibly causing a slight vacuum leak once the car was hot (due to expansion). Put the original BOV back on (nice rubber gasket) and went for a long drive, idles pretty good and no longer wants to stall, but boost doesnt feel as steady and strong (perhaps standard BOV leaking boost, sorry dont have a gauge). So came back home put the GFB back on but used some RTV gasket with the paper gasket too. Went for a drive, but not as long as the others and the car idles pretty good and doesnt want to stall anymore but boost does feel alot more steady (could be in my head though). There was also mention along somewhere that the GFB BOV body was made out of Aluminium and the plunger was brass or something and this could be a problem once hot as two different metals expand differently and may cause some leakage. Once i have gone for a long drive i'll let you know if the problem comes back (fingers crossed)

Thank god for forums!!!
Mike

[MY05WAGON]

Yep its official, went for a long drive today and its all good.

I use to particularly feel the bad idle when the a/c was on, the thermos would cut in and out and everytime i would feel slight wobbles. Now its smooth as!

I did noticed when i had the old 50/50 hybrid set up that when throttling off i would sometimes hear a double psssst (only slight on mild throttle). Only explaination i could think off would be once venting the air would push the piston up then due to the leak it would loose its oomph, piston would be pushed back down by the spring and rest of the air would vent through the leak. The only thing is upon boost i couldnt hear any leaks, but i have removed the resonator and there is induction noise which possibly could have masked the leak. I also have different mufflers on which created some noise as well.

Another symptom which is now gone is under heavy acceleration through 1st-4th gear then throttling off, once reapplying the throttle for the first time the car use to feel as if it would stumble (not all the time but most) maybe the leak was worst than i thought.

Boost gauge would have been good to diagnose the problem. I did notice alot of hoses did not have any clamps, potentially could be a problem for guys running higher boost levels.

Hope this helps

Mike

[XRC15T]

good to hear it worked out Mike.

[norbs]

Thanks for the tip Mike. Any reason you went for an aftermarket BOV? I was considering getting one for the noise but have decided against it due to issues similar to what you have encountered.

[MY05WAGON]

Thanks XRC15T im just glad its sorted out.

Norbs i went with an aftermarket BOV cause i wanted some noise. I chose the GFB because it could be set to 50/50, 100% recirc, 100% vent to atmosphere and also the engine cover does not need to be modified to fit it in and it takes about a minute to change the setups. I've now gone from 50/50 to 100 recirc, its a nice change driving without the psst now.
It did feel like boost was more constant with the GFB compared to the standard, I have read that some people think the standard BOV's do leak, perhaps this was the case with mine, couldnt tell you for sure cause i dont have a boost gauge.

Mike