Crushed BOV leaking!

[a1320eclipse]

OK, so friday we crushed my 1st gen bov and all was good, the car was pulling hard and runnning fine, all of the sudden the car started running like crap. So finaly today i did a boost leak test and the bov is leakin horribly back into the recirculation pipe. Would this be causing my car to run as crappy as it is, it still makes boost and pulls hard in 1st and second, but 3rd and 4th are a joke. This is the only thing ive found wrong with my setup, and the compression test #'s are way good, 155, 155, 155, 160. any help is appreciated.

 

[90blacktsiawd]

Yes a large boost leak will make your car and run like ass.

 

[zippyshoe]

This could very well be causing the problems that you are having. Your turbo may still be capable of building boost despite a sizeable boost leak - it will be working much harder to do so, however. I would recommend replacing your BOV and running another boost leak test to catch any additional boost leaks you may have. Once this is done, at least you will know that this problem has been corrected. If you are lucky, the problems you are having will be eliminated in the process.

 

[modifyer]

I have the same problem , mine also a crushed 1g was leaking not past the piston but though the small hole that goes to the diaphram. I did a leak test today and was expecting to find lots of leaks but the only thing that would not hold was the BOV.
In order to prove I was right I made up a gasket that sealed the small hole and the car worked much better .

 

[a1320eclipse]

ya its still building boost up to 18lbs, but since this problem came along, the turbo and manifold have been getting red hot with 3rd gear pulls now and its leaning out a little now, so im thinking that the bov is leaking air back into the recirculation tube which is unmetered air causing a lean condition, and the turbo is working much harder now to keep up with trying to push 18lbs. sound right?

 

[90blacktsiawd]

No the air has already been metered so it's not that it's letting air back in that it wasn't expecting. The fact that you have a large boost leak is causing the turbo to work even harder to make the 18 psi that it normally does. If your losing 5 psi through the bov then your turbo is trying to push 23 to keep up. And because of that your intake charge is hotter as more air is being combusted.

 

[zippyshoe]

ya its still building boost up to 18lbs, but since this problem came along, the turbo and manifold have been getting red hot with 3rd gear pulls now and its leaning out a little now, so im thinking that the bov is leaking air back into the recirculation tube which is unmetered air causing a lean condition, and the turbo is working much harder now to keep up with trying to push 18lbs. sound right?

I'm not sure that I agree with this explanation for your turbo and manifold getting red hot. The air that is leaking past the BOV and flowing through the recirculation tube actually is metered air since this air has passed through the MAS when it first entered your intake. This air is just taking a roundabout route through your intake since its leaking past the BOV, going through the recirculation tube, re-entering the turbo inlet, and then being compressed again by the turbo. Since this air is never leaking to the atmosphere, this metered air will eventually enter your engine. The red hot turbo/manifold could be due to the turbo simply working harder to achieve your set boost pressure. Also, from what I understand, it is normal for the turbo to sometimes glow red after numerous WOT pulls.

EDIT: Beat me to it, 90blacktsiawd. I have to learn to type faster.

 

[90blacktsiawd]

EDIT: Beat me to it, 90blacktsiawd. I have to learn to type faster.

Next time my friend, next time.

Yes the turbo and manifold do glow after a hard pull or a decent drive.

 

[a1320eclipse]

ya i was wrong in thinkin it was unmetered, and as far as the glowing part, it has been on 18lbs for 2 months now and never glowed till this problem, im just a worrier and with the downpipe i should have easily hit a 12, the car was so much faster, and the best i could manage yesterday was a 13.5@98. so i just wanted to be sure that the leaking bov was going to hinder the cars performance.

 

[a1320eclipse]

turns out that it wasnt the bov leaking, i put on another and it was still doing the same thing, so then i realized it was the mbc that was bleeding off pressure, it starts bleeding of at like 10 psi though, not sure if thats right. so i finaly got to the point of frustration that i was goin to start over. for some reason the cam angle sensor has almost been way way retarded to keep from getting audible detonation. so i loosened it and turned it back to about half way and holy shit, the car came alive again, so was the addition of the downpipe what caused this, cause it took several miles for the ecu to readjust for the dp, or is that even a possibilty, it feels really good now, just a little more fine tuning, but all i did was advance the cam angle sensor. any thoughts?

 

[TSIfreek]

According to your your mods list you are still on stock 450s and stock side mount. max I have seen on the 450s is 12- 13 psi and thats over 100% DC.

 

[oldman]

turns out that it wasnt the bov leaking, i put on another and it was still doing the same thing, so then i realized it was the mbc that was bleeding off pressure, it starts bleeding of at like 10 psi though, not sure if thats right. so i finaly got to the point of frustration that i was goin to start over. for some reason the cam angle sensor has almost been way way retarded to keep from getting audible detonation. so i loosened it and turned it back to about half way and holy shit, the car came alive again, so was the addition of the downpipe what caused this, cause it took several miles for the ecu to readjust for the dp, or is that even a possibilty, it feels really good now, just a little more fine tuning, but all i did was advance the cam angle sensor. any thoughts?

This is why you shouldn't tap the BOV line for your mbc.

 

[a1320eclipse]

wheres hould it come from, i heard if your running over 15lbs, thats the best place.

 

[90blacktsiawd]

What's wrong with the nipple on the stock lower pipe? I think keeping it close to the turbo is best for reaction time.

 

[oldman]

wheres hould it come from, i heard if your running over 15lbs, thats the best place.

Where did you hear that from? Care to explain?

You were leaking pressure out of the recirculation tube during a leak test because the mbc was bleeding off pressure, every mbc does, causing the BOV to open prematurely which is exactly what happens when ever you're under boost. This is one of many reasons why the BOV line should be left alone.

 

[a1320eclipse]

On the turbo xs instructions it said over 15 to run it from the intake mani. not the nipple off the charge pipe. but thanx everyone for clearing this up for me.

 

[oldman]

On the turbo xs instructions it said over 15 to run it from the intake mani.

Whether this statement is correct aside, I have serious doubts until I hear their rasoning behind it, intake manifold pressure doesn't have to be the BOV line. The BOV line should never be used for the mbc because the proper functioning of the BOV requires precise pressure signal on the BOV vacuum line as you have discovered through your boost leak test.

 

[daren_p]

Whether this statement is correct aside, I have serious doubts until I hear their rasoning behind it, intake manifold pressure doesn't have to be the BOV line. The BOV line should never be used for the mbc because the proper functioning of the BOV requires precise pressure signal on the BOV vacuum line as you have discovered through your boost leak test.

Yes, my TurboXS instructions said the same, but of course I didn't follow them. Take you boost controller source from comp cover, jpipe or lower ic pipe. Leave the bov vacuum line connected to the intake mani & nothing else.