Boost leakdown test question

[SkaterNSX]

Today I ran a boost leakdown test on my Talon, to maybe help solve some small problems its been having (I.E. sputtering/jerky car under boost, really really low gas mileage) And I could not hold pressure inside the intake piping. Doing my research suggested that I had a very large air leak somewhere in the piping or manifold that my pump (it was a giant foot pump) could not keep up pressure with. Well after realizing that air was coming from my valve cover breather hose I plugged it and tried again, only to still hold no pressure and when I removed my oil cap I did get a substantial amount of air pressure released. I performed this a few more times to find that there would be no pressure in the block after about a minute leading to a leak somewhere else?. I am afraid that I might have bad piston rings, or maybe deeper problems. I am looking into getting an air tank for my next boost leakdown test. Any help or comments about this will be appreciated.

Sorry about the long explanation, wanted to get it as thorough as possible

 

[No_Skillz]

If you are pressurizing the intake and the valve cover breather hose is leaking, you might have problems. Do a compression check.

 

[SkaterNSX]

I will run a compression test later on today and then go from there, thanks for your help!

 

[SkaterNSX]

After running another test waiting for my friend to bring over the compression checker, I found that my PCV valve is stuck open, could this attribute to the pressure in my engine?

 

[Dream On]

Yeah. It would definately cause air to go back in the wrong way. Replace it and test it again. Get an OEM one as well, since many aftermarket ones leak. Oh, and you don't have to buy a tank to do you leak test. Just take your car to a gas station with an air compressor and do you leak test there.

 

[DGajre777]

Oh, and you don't have to buy a tank to do you leak test. Just take your car to a gas station with an air compressor and do you leak test there.

How? I thought an air compressor at a gas station pushes out a lot more psi.

 

[Dream On]

Just watch the boost gauge, it shouldn't fill up so fast that you can't pull the thing off before it gets too high.

 

[DGajre777]

Just watch the boost gauge, it shouldn't fill up so fast that you can't pull the thing off before it gets too high.

If the compressor is outside and you are doing a boost leak test in the engine bay, how can you watch the boost gauge. I still prefer gettting a tank and setting it to 15psi.

 

[Dream On]

Well, I myself have something called friends.

 

[DGajre777]

Well, I myself have something called friends.

That's not what I was talking about...

 

[SkaterNSX]

well guys I got a tank and ran another boost leak test with way better results, I removed the PCV valve hose and blocked it off as well as the valve itself, and found that my stock 2G blowoff valve is leaking as well as a number of small leaks in and around the TB/Intake manifold area. Tommorow I will be replacing the PCV valve and the gaskets on the TB, then running another test. thanks for all your help!

 

[Dream On]

Yay, a happy ending.

 

[alex99gst]

I'm glad it worked out for you, but whenever I try to run a boost leak test, the boost gauge never moves (according to my dad). I set the tank output pressure to 30psi and as soon as I hook it up it drops to like 10 and falls. I completely unhooked my UICP and couldn't hear any air coming out or anything. Soapy water didn't show any leaks at all. I do have the dejon powerhouse leak stop kit and I wonder if it is leaking pressure out of that (but I can't hear any air going through it). I might build another tester or something because I'm not happy with mine to begin with, but I'm having trouble holding boost during the leak test and if anyone has any advice, shoot it my way. Thanks