2G leaking out of blow off valve during BLT?

[tay97gst]

First off I have a 1g bov. During yesterdays boost leak test I noticed that air was escaping through the recirculation tube part of the bov when putting 15-18psi through the system. Does this mean the diaphragm is bad? Anyway i can test it on a 1g or should i just replace it?

 

[canada4g63]

Spray some soapy water around were the bov is bolted down to.

 

[92AWDHX40]

It could be the diagram or a leaky gasket.

 

[tay97gst]

It's not leaking around the blow off valve. I did a BLT yesterday and didnt see any bubbles around the bov. Im positive it's coming through the bov itself.Its a pretty good amount of air i dont need soapy water to tell me there's air coming through.

 

[SpiderGST]

Sounds like you have a leaky leaky BOV. Just find another 1g BOV and your set.

 

[rlacasse1]

Are you blocking off the intake at the throttle body when you do it? Or are you pressurizing the manifold as well?

 

[tay97gst]

Are you blocking off the intake at the throttle body when you do it? Or are you pressurizing the manifold as well?

All i do is remove the stock intake and put the tester on the turbo. Leaving the recirculation part of the bov open, and the three lines that connect to the intake open.

 

[rlacasse1]

Which three lines that connect to the intake?

Basically, what I'm driving at, is this. Is the top side of the BOV seeing pressure? Cause it will open if it isn't.

 

[thomcasey]

Isn't 15-18lbs the limit for an uncrushed 1g BOV? If you want more, you will need to crush it to hold more boost.

 

[tay97gst]

Isn't 15-18lbs the limit for an uncrushed 1g BOV? If you want more, you will need to crush it to hold more boost.

Well when doing a BLT shouldnt i be putting the max boost i'll be running through the system? My max boost is 15psi, which is just stock boost(no mbc or anything), so i figured the 1g should definitely be able to take it when i put 15psi in the blt.

Basically, what I'm driving at, is this. Is the top side of the BOV seeing pressure? Cause it will open if it isn't.

Is there a more efficient way to do the blt then? I just thought this was the way to do it.

 

[re-rx7]

MAinfold pressure holds the diaphram down.

 

[daren_p]

The way your doing it sounds correct. He just wanted to verify the top of the diaphragm was seeing pressure as well (like it would under normal operation). If you didn't have the top line connected during a BLT, it would cause the BOV to open sooner then normal.

From my experience (ran a stock 1g valve years & years ago) mine started to leak around the same pressure (mine was purchased new, only had a couple summers use, so defently wasn't old or weak). As someone has mentioned, this is probably around normal for an un modded stock 1g valve. Also, 15psi is higher then stock boost. On a 2g, stock boost would be 12-13psi. I would assume a 1g to be around the same, or slightly less.

 

[snapc3]

Also you can check the valve face and seat for any kind of build up that would not allow it to seat and seal.

 

[tay97gst]

Also, 15psi is higher then stock boost. On a 2g, stock boost would be 12-13psi. I would assume a 1g to be around the same, or slightly less.

Well it's probably more like 14 but there isnt any creep or spike or anything it's just a clean 14psi climb so I'm not too worried. Maybe the previous owner did the bcs mod for an extra pound of boost or something who knows.

So... should i get a new bov or just not worry about it?

 

[chevaholix]

Aslong as it holds youre max boost and seals good you should be fine with the one you have unless you plan to run higher pressure anytime soon i wuldnt worry about it

 

[daren_p]

Well it's probably more like 14 but there isnt any creep or spike or anything it's just a clean 14psi climb so I'm not too worried. Maybe the previous owner did the bcs mod for an extra pound of boost or something who knows.

So... should i get a new bov or just not worry about it?

Thats up to you. If its stays closed at the boost pressure your running, nothing to worry about currently. If the valve is open at the boost level you run, your working the turbo harder then you normally would as it now has to overcome the leak to achieve the same boost pressure. The T25 is small & working hard as it is, so adding leaks ontop, will tend to stress it.

 

[tay97gst]

Thats up to you. If its stays closed at the boost pressure your running, nothing to worry about currently. If the valve is open at the boost level you run, your working the turbo harder then you normally would as it now has to overcome the leak to achieve the same boost pressure. The T25 is small & working hard as it is, so adding leaks ontop, will tend to stress it.

Well if it leaks out of the bov at ~15psi during a blt, and my max boost is ~14psi, theoretically it could be leaking out of the bov during wot runs at 14psi correct? And that means I should replace it.

Is there any way to directly check a bov?

 

[volkerding95GSX]

Have there been any updates on this OP?

I am having the EXACT same BOV leak symptoms when I do the same BLT the OP did.

My only difference is I can feel the BOV leaking no matter what the pressure is; it doesn't wait to get to 15-18 psi first to leak.

The only other boost leak I am having is a small one at the TB elbow gasket and a small one at the BISS screw.

Any advice?