Boost Leak Testing

[jccjr1982]

OK I did a search, but if you do a search with terms "boost leak" if will lead to every thread that has the works "did you do a boost leak check?"

I just built a boost leak tester from the instructions in the Tech Guide. I connected it to the turbo from where the intake pipe is connected. No MBC was connected while performing the test.

I used a portable bike pump. My question is... how much pumps does it take? I must've pumped it over a hundred times yet my pressure gauges read zero, and I get no resistance from the pump. Also if I press the valve stem pin in, no air seems to be coming out. I do notice while pumping and doing the spray bottle/soapy water trick, I get a very very minute amount of air coming out of my BOV venting holes. But I don't think enough air is coming from it to cause no pressure build up at the rate I'm pumping.

Do I just need to pump it more, or get a bigger pump? Am I suppose to block off anything?

 

[oldman]

try an air compressor.

 

[madman]

No offense man, but that is really funny.... just trying to picture someone using a bike pump..... man your arms must be tired.

Definitely get a compressor or find someone who has one.

It's also been mentioned getting a 2-10 gallon tank that can be pressurized and fill it will air and use that. But if you have multiple leaks, like I did, then you may run out of air before finding them all. Then you got to go back to refill it. A compressor would be best.

p.s. I just read the VFAQ again and like I mentioned above he used a 7 gallon tank from Wal-Mart....I think the bike pump was meant to be used to fill the 7 gallon tank instead of having to go to a gas station, not to pressurize the entire system..... it could be very easily confused to mean the wrong thing, they should re-word that.

 

[MrBoxx]

About three years ago, I bought all the materials needed to build a boost leak tester and perform the test, including the foot operated bike pump. Needless to say, I did not succeed in doing a boost leak test.

7 gallon air tanks at Wally World are about $19.99.

 

[jccjr1982]

Yeah the article said bike pump so I was thinking it shouldn't take too much air to build pressure...but now that I think about it is this bike pump took a long time just to inflate a bike tire... I'll borrow an air compressor.

Thanks guys

 

[jccjr1982]

Ok I used a 125 PSI compressor, I regulated it to right under 20 PSI...

I sprayed the IC and its joints, the UICP and LICP pipes/joints, the BOV, TB, and BISS.

My POS 2 month old BOV is leaking from the vent holes (the piston is not even getting pushed up), and the BISS screw port.

I'm gonna get a new o-ring for the BISS Monday, and eventually I will get a UICP with a SSQV BOV/recirculation kit.

I have a question about the BOV though. It's a 1" BOV I bought off eBay (picture attached)... since its too small to clamp to the stock BOV port, I cut a piece of the the stock BOV recirculating hose to wrap around the BOV then clamped it to the UICP. Amazingly it was not leaking around the BOV when I tested it...

Onto the question, since the spring, piston, and mount are smaller that what is normally required (1" as compared to 1.5"), will using this BOV cause premature venting? I do notice I get flutters once in a while, and my BOV is EXTREMELY LOUD... alot louder that other venting ones I heard... I mess the the adjustment on the BOV, but I seem to get the same results no matter how loose or tight it is...

 

[jccjr1982]

By the way, when I apply air pressure to the system, I hear something like a drop of oil/water hitting a pan with a slight echo... At first I thought it was just the soapy water dripping, but I let that dry up, and I only hear the noise when applying pressure.

Did I blow something? My car does runs fine and boosts no problem...

I checked for shaft play, up-down/side-to-side/in-n-out... none whatsoever.

 

[DROOPY209]

have you tested for boost leaks with the car hot or cold?

you should test it with the car hot.

 

[madman]

have you tested for boost leaks with the car hot or cold?

you should test it with the car hot.

Why?

 

[alex99gst]

For starters, you need to switch back to the stock BOV configuration to where it is vented back into the intake. That is metered air you are losing, which will hurt your gas mileage and make your car run more rich than it already does. I'm not sure about the weird noise you are hearing. Don't forget to open up the oil cap and listen for a whistling sound to see if youre PCV valve is leaking. I always forget this and mine is leaking pretty bad.

 

[jccjr1982]

Yes I was one of those "I want a cool sounding car so I'm gonna vent! *thumbs up I'm gonna be soooooo cool*" guys, but after all the no-no's everyone drills on venting, I'm gonna go back to recirc as soon as I buy a FMIC/IC piping w/ a 1g flange. But I will not to go back to stock BOV, because my cars feels like it runs worst with the stock BOV compared to the venting one I got. I also noticed the tension on my stock BOV is ALOT softer than my venting BOV... I mean it takes almost no effort to push in.. my venting BOV spring has alot more resistance.

Also thanks for the oil cap/PCV valve trick. I always hear people saying to check the PCV valve.. so I just assumed to spray it with soapy water...

 

[kmoore]

are there any hoses that need to be un-plugged when do this? And why would you want to do this test when the car is hot?

 

[jccjr1982]

are there any hoses that need to be un-plugged when do this? And why would you want to do this test when the car is hot?

If you got a Manual Boost Controller, its best to unplug the "in" port and cap off the hose you just unplugged. If you don't, it will "bleed" alot of air, and probably distract you from finding an actual leak.