Jump to content
SAU Community

Where Can There Be A Leak In Bov System?

Kwyjibo

By Kwyjibo,
in Engines & Forced Induction

 Share

Recommended Posts

Kwyjibo Rising Star

Kwyjibo

Posted
Posted (edited)

I have a basically stock R32 gtst, only real modification is 3" turbo back exhaust. It currently runs at a bit over 11psi. The back of the car gets really dirty after about a week of driving, I had a friend drive behind me and the only smoke he could see was a puff of black smoke whenever I backed off. My car has also been backfiring sometimes when I back off.

Anyway I found out that the standard BOV had been blocked off at the crossover pipe, which is the most likely cause of this(coils and plugs are basically new, no misfires).

The problem is whenever I remove the piece of metal blocking the BOV the most boost my car will run is 9 and that is only for a split second and it drops off to 8. I have tried it with another BOV that was working fine on another car and the same thing is happening.

Where would there be a leak? The only place I can think of is BOV > intake piping(after AFM), but I wouldn't have thought this area would hold boost anyway since it goes right out to the filter. Could it be the vacuum hose leaking that leaves the BOV open or something??

Thanks for any help.

Adrian

Edited by Kwyjibo
BHDave Grand Master

BHDave

Posted
Posted

The factory bov has a bypass in it to make the operation a bit smoother. That may be causing your loss of boost (though 2 psi does seem excessive). You can mod the stock bov to block up this hole.

You haven't introduced a leak when changing bovs have you? and it is plumbed back right?

Kwyjibo Rising Star

Kwyjibo

Posted
  • Author
Posted

Well I figured that but I also remembered the BOV I borrowed had a screw in the bottom of it(which I understand effectively blocks off that leak). Either way it should still be running at least standard RB20 boost, not 8. Yeh it is plumbed back into just after the AFM.

Cubes Grand Master

Cubes

Posted
Posted
The back of the car gets really dirty after about a week of driving

All bets are on having a gutted or no cat. :)

Backfiring is caused by the blocked off bov.

If the cat isn't already gutted my bets are on it being stuffed due to the backfiring etc. :(

Have you connected up the pressure feed to the bov correctly? It may be that its blowing open a touch if its boost feed isn't connected.

Block the bov back off; use a coke can, chop it up and see how u go. If it holds boost then the problem lies with the bov.

Kwyjibo Rising Star

Kwyjibo

Posted
  • Author
Posted
Have you connected up the pressure feed to the bov correctly? It may be that its blowing open a touch if its boost feed isn't connected.

Block the bov back off; use a coke can, chop it up and see how u go. If it holds boost then the problem lies with the bov.

Yeh I've put the piece of metal(it probably was a can of some sort) back in a few times and each time it fixes the problem. Another BOV didn't fix the problem. I'll check the pressure feed but it looks fine to me. Any idea how to check if my cat is working?

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 account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • GTSBoy
      Rb25det Belts Change

      By GTSBoy · Posted

      Yes. It's either "2 wires", or 1 wire, depending on how you look at it. It is the connection that ties the battery -ve to both the chassis and the engine. Every electron that goes in or out of the battery goes through those 2 small spots (on the inner guard and on the engine block). If those are not clean and tight, then shit starts to suffer. Yeah, but measure it again cold in the morning, after it has had hours to rest. You can't usefully test the charge state of a battery immediately after it has been running because the alternator puts a surface charge onto the plates that takes a while to soak in and balance out. It will always read higher, and potentially look properly healthy, when fresh off of charge. But hours later it can look a lot less healthy. It's also worth measuring the battery voltage while cranking, although this can be difficult with a typical DMM because the screem update rate is so slow on most of them. An analogue voltmeter is actually a better tool for that. If the voltage drops too far while cranking, it is a sign of a poor battery. Although I don't think we're necessarily looking for a weak battery here - just wanting to exclude it.
    • alexburns
      GTR Festival (Aus) - 2025 - Stagea Alley

      By alexburns · Posted

      https://www.facebook.com/share/15ZMn5oXtc/ Updated Event (so its not private and can be shared easier)  Attempting to coordinate a big push of Stagea's to this years GTR Festival. Great event last year and hoping for the same this year.  Discounted tickets 20% off for their various tickets until the 3rd of Feb Monday. Drags, show and shine etc.  I've emailed them to ask to set a location aside for the Stageas for the show and shine - they are happy to do so if we can get them numbers, I'm happy to keep track of that. Entering as Nismo category.  I'll be road tripping up from Melbourne, would be cool to convey if people are interested, maybe there is SAU convoys from each capital? If you have ideas about that let me know.  https://gtrfestival.com.au  
    • Skip33
      Series 2 R33 GTS25T?

      By Skip33 · Posted

      Does have series 2 airbag steering wheel and passenger side airbag also.
    • Skip33
      Series 2 R33 GTS25T?

      By Skip33 · Posted

      Do I have a series 2 or has someone spent money to have a series 1/1.5 look like a series 2? Everything I have read says the series 2 came out in 1996. I have a car manufactured in December 1995. The exterior, engine and interior are all series 2 other than the dash facia is series 1. Paint code is also kr4 that I believe is only available on a series 2. I have a VX Vehicle History Report and it says Grade: GTS25T TYPE M2 Manufacture date: 1995-12 Make: NISSAN Model: SKYLINE Body: E-ECR33 Grade: GTS25T TYPE M2 Engine: RB25DET Drive: 2WD Transmission: F5
    • silviaz
      Rb25det Belts Change

      By silviaz · Posted

      I went to Repco to get them to test the battery using their tester (not a volt meter), alternator shows 14.3v when running, and when the car was off after the it was on full load I think it was 12.6v but the guy said it was all good. Terminals are all clean, no corrosion. Though I coulda sworn when I tightened up my alternator belt the car idles a bit higher and the steering wheel shakes a bit until it's warmed up. I wanted to confirm for the earth cable/s, are you referring to the 2 wires that are bolted onto the frame rail under the battery? I might be overthinking this a bit.
×
×
  • Create New...