How do I make / buy / use / troubleshoot a boost leak tester? [merged]

[Turbo Monk3y]

All boost leak tester threads are combined here.

i read somewhere maybe the Vfaq about making or buying a boost leak tester of some sort but never found it.... the reason being my acceleration seems slower than normal and all ive done to my stock car so far is take out the air box put on a K&N filter and cut the dump tube i have my boost guage sitting in a box not hooked up yet. and since those 2 mods it when i go wot on the car i can hear the turbo spool up and it sounds nice but i can also hear a sound as my rpm increases the SHHHHHHHHHHHHHHHHHHHHHH sound does too. the sound comes from the same area as the BOV i think maybe i got a #@%#@%#@%#@% stock bov and it cant handle over 11-13 psi??? Then i shift and it makes the nice BOV sound WHOOOOSHHHH... but my car seems to be a little slower.. any ideas before i go check every tube clamp and tube????

 

[Cs4g63]

Yes the boost leak test will work like this.

 

[chuckg]

If you just unhooked the recirculation tube from the bov back into the intake, youll be fine. Since the bov opens under vacuum, it shouldn't leak when you fill 'er up.

 

[Mytrn2brn]

Thanks for the fast response.

 

[Cs4g63]

Not a problem.

 

[Mytrn2brn]

Ok guys getting a little nervous now. hears the deal this is my first time doing this test and i'm doing it by myself. I don't have an aftermarket boost gauge but i have my compressor set at like 15 psi that should be safe right? Also does anyone know how long the system will take to pressurize (5second -10second) i just don't what to blow anything. Also I have on of those pen style tire pressure gauges trying to measure the psi in the system an i'm getting nothing. I know it's junky but I'm trying and tip would be very appreciated.

thanx

 

[FORMONTOYA]

Since this is your first test (and probably the cars first test also), it might have so many leaks that it will not hold anything at this point. Once you start to close off the leaks it will start to hold some pressure.

Your places to check should be all couplers, BOV, BOV flange, IC core, throttle body shaft and gaskets, injector seals; basically any connection point/fitting between the turbo and the head.

Generally I will not test at the turbo inlet, instead I test from the IC inlet as the turbo seals are a pressure activated seal which means they rely on oil pressure to completely do their job. Turbo seals have been known to leak even if new because of this.

Since this is your first test I would suggest you start at the throttle body, fix the leaks as you go, and work your way forward to the turbo.

I don't know what kind of compressor you're using, but a cigarette lighter pump will NOT work. It does not put out enough volume of air to do the test properly.

 

[Mytrn2brn]

I have a 125 psi compressor, that should do it right? and instead of going from the turbo inlet i should try the IC intel. That would be the UICP right? disconnect that pipe from the IC and attach the tester there right? Lastly I have my compress set at 15 psi how long should i try to fill the system with out blowing anythig?

BTW I don't think i have that many leaks because the car will still make boost but it sputters for a few seconds first.

 

[FORMONTOYA]

The compressor is good for this test.
Start at the throttle body elbow. The reason I say to start there is that you will have a smaller area to test and fix before moving down the line.
You will be surprised at how many leaks you have, especially if it's the first time.
It should not take more than a few seconds to reach 15PSI if it's holding. You can fill it up with 15PSI and (if it would hold) the compressor could conceivably stay on for a week without doing any damage. Once you set your regulator to 15PSI and fill with 15PSI, the compressor shuts off and no more pressure will enter the system.
"Sputtering" is a good sign of boost leaks.

 

[romeen]

I have a 125 psi compressor, that should do it right? and instead of going from the turbo inlet i should try the IC intel. That would be the UICP right? disconnect that pipe from the IC and attach the tester there right? Lastly I have my compress set at 15 psi how long should i try to fill the system with out blowing anythig?

BTW I don't think i have that many leaks because the car will still make boost but it sputters for a few seconds first.

Your 125 psi compressor is fine.
The IC inlet would be where the LICP connects to the IC.
IMO the best way to do a boost leak test is with an air pressure guage on the boost leak tester, makes it much easier and safer. I'll try to find the link to the DIY tester with guage which I followed, works great.
You may have a large leak at the tester itself, either in the tester or a poor coupler seal between tester and whatever you're hooking it up to.
Also just because you can make boost when driving doesn't mean you dont have boost leaks.

 

[romeen]

Here it is:

http://www.dsmtuners.com/forums/showthread.php?t=201554

Works perfectly. I did use a higher pressure guage.
Good Luck.

 

[Mytrn2brn]

Oh the LICP that will make thing much easier. Please keep the help coming as you can see i could use all that I can get.
I start at the TB and work my way back. Also i thought i did pretty good building the tester but if you guys know a better design that the one in the FAQ"S i guess i'll try to put together another.

Thanks Guys

 

[Mytrn2brn]

Here it is:

http://www.dsmtuners.com/forums/showthread.php?t=201554

Works perfectly. I did use a higher pressure guage.
Good Luck.

That's looks petty good and it looks like it going to cost more that $8 bucks to make oh well if it works better. I have seen all the part for that one at Home Depot but the gauge, where can i get that gauge. well back to work.

 

[romeen]

By far the best way to identify the location of the leaks is to spray soapy water over all couplers, joints, etc. and look for the telltale bubbles.

 

[romeen]

Mine cost $14 but worth every penny. HD had the guage as well, it was intended for use in natural gas setups. But I later stumbled upon a cheaper one at ACE Hardware.

 

[Mytrn2brn]

Had the soapy water since the beginning.

Another $14. well if it work

 

[FORMONTOYA]

I personally have not been to concerned with having a gauge on the test piece. If you set your regulator on the compressor to your test pressure, then it will not be a concern as to "if you're going to over pressurize the system" unless the set point is way up there (but 15PSI is NOT too much). Once a good regulator is set, it will not allow any more pressure than the "set point" to enter the system.

I test mine to 25PSI and it will hold more than long enough for me to check the boost gauge to see how fast it might be falling. I (and you) will know if it's leaking or not without looking at a gauge. My tester is nothing more than a 1-1/2" PVC cap with a tire stem in it (cost $3), it fits inside of a 2-1/4" coupler. I use one of the coupler clamps to attach it.

But it's definitely your call as to how you want to make one.

 

[96gstdsm]

Ok i'm going to make a boost leak tester. What size coupler do i need to fit up to my stock t-25? Would i need to change it if i upgrade my turbo? Or are the inlets the same size? I am going to upgrade to 14b, t-25 or evo316g shortly as my turbo is starting to whine, unless i am lucky and the boost leak test shows it is just a leak. It just connects up to the turbo correct? Just take off the intake and then attach there?
Please let me know. Thanks alot.
--Ryan,

 

[deletrius]

i believe it is 2.5", and the evo3 and 14b use the same size inlet. and if you can do this test then you can go out and measure it yourself. but anyways http://www.vfaq.com/mods/ICtester.html Yes, you take off your intake pipe and put this over the turbo inlet.

 

[romeen]

i believe it is 2.5", and the evo3 and 14b use the same size inlet. and if you can do this test then you can go out and measure it yourself. but anyways http://www.vfaq.com/mods/ICtester.html Yes, you take off your intake pipe and put this over the turbo inlet.

The o.d. of the compressor inlet on all the 16G turbos is 58mm which is about 2.25". The 14b has a smaller compressor inlet. I'm not sure about the inlet of the T25 but I think it is smaller than 2.5". Better to just go ahead and measure it.

 

[96gstdsm]

Ok thanks alot guys. Yeah i didn't have time to check it earlier as i was at work and just wanted to buy the parts online to make one. Yeah just read the vfaq article. My bad. Was in a hurry and couldn't think at the moment.
Guess i'll hit up home depot in the morning.

 

[kenamond]

The T-25 and FPB28 inlets are 2.125" OD. A 2.5" coupler is okay for both.

There is a superior boost leak tester design out there if you're interested (more expensive, though)...but I have to go find the link.

 

[kenamond]

Here's one alternative. I know there's another but I haven't found it yet...

http://www.dsmtuners.com/forums/showthread.php?t=169435&highlight=tester

 

[kenamond]

Here it is!

http://www.dsmtuners.com/forums/showthread.php?t=201554&highlight=leak

The nice thing about these is that you don't need to have someone watch your boost gauge for you.

 

[PieEyedPiper]

It is my opinion that you should not pressure test at the turbo inlet, but rather, at the intercooler inlet. Also have the oil cap off, as per oldman's suggestion.

pro's
-cuts out the middle man (turbo) which can stop you from building any pressure due to bad seals or just seals that don't really seal until there is oil pressure from the engine running
-will not exacerbate leaking seals on your turbo

con's
-you can't test your lower licp for leaks, but I think a little common sense can overcome that

 

[romeen]

It is my opinion that you should not pressure test at the turbo inlet, but rather, at the intercooler inlet. Also have the oil cap off, as per oldman's suggestion.

pro's
-cuts out the middle man (turbo) which can stop you from building any pressure due to bad seals or just seals that don't really seal until there is oil pressure from the engine running
-will not exacerbate leaking seals on your turbo

con's
-you can't test your lower licp for leaks, but I think a little common sense can overcome that

You do have a point although I have never had a problem testing at compressor inlet.
Instead of removing oil cap I disconnect PCV from VC but leave it hooked to IM. That way I can tell if my PCV is leaking (which never happens on our cars, right? ) and I wont accidentally pressurize my crankcase.