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????

 

[tom04841]

Thermo coupler for the EGR. Do the Vac line elimination and be done with it.

 

[Tony90TSI]

You have the tester on the Upper intercooler pipe going to the TB correct? You should do the test after warming the motor up too as it will seet the rings and slow down the blow by passing the rings which can also give you the sound of a leak coming from the valve cover. Next you might do a compression check just to make sure the rings and everything are still good if its leaking alot.

 

[Novablue454]

Vacumn line elimination? I would love to do that. way too many of those things under there. Could you link me please?

 

[FORMONTOYA]

One thing that doesn't get mentioned enough is to rotate the motor to roughly 30* ATDC to insure that each cylinder is closed, meaning that at least one set of valves (either intake or exhaust) in each cylinder is closed so the air doesn't just pass straight through.

As old as your car is you might want to look at the EGR valve as it's another leak point that also isn't mentioned very much.

Also testing at the upper pipe..................possibly the BOV and gasket if testing that far back. Injector seals, PCV valve, any nipple coming off the intake, throttle body seals and gaskets........basically ANY connection coming off the intake track.

 

[Dream On]

Sounds like the other leak is your biss screw o-ring. Search on here for how to fix it for like 10 cents. I would also check the lower injector seals and vacuum lines around the FPR.

 

[Novablue454]

http://www.dsmtuners.com/forums/showthread.php?t=198327

 

[mitsured420]

they sell a good boost leak tester on ebay for about 40 bucks has an adjustable regulator with guage so you dont blow your intake gasket i have one worth the money for ease of hookup and use conects to your compressor air line.

 

[elfroggo]

Yeah but a boost leak tester costs like 5 bucks to make in parts. Is this a compressor that doesn't have an air tank? Otherwise you'll know pretty fast if you're building pressure or it's leaking out pretty fast.

 

[eboy0]

I'm having a problem building boost using one of those homemade testers, it seems to work on the throttle body, but won't work on the turbo inlet anymore... i put it on there and when i pump it w/ my bike pump, the psi just stays at 0, tested pipe by pipe, until i reach the turbo outlet and no leaks, its only when i pump through the turbo inlet where it doesnt' build boost.
Anyone help?

 

[Bodack]

Are you using an aftermarket gauge? The stock one will NOT give you a reading doing a boost leak test. Also, use an air compressor unless you can pump that bike pump very fast.

 

[spinz4]

A compressor will help you out, and I hope your not using the stock gauge...

How long does it take you to pump up a bike tire with that thing? Now compare that to your intercooler pipes intercooler and all??

 

[eboy0]

Good points made... it's a fairly large pump, and it pumps up tires pretty fast.
The pump comes with a gauge, and i have a autometer boost gauge aswell.
Both my compressors have broken regulators, and they shoot out at 100 psi, how exactly would i use them? Plug it in and out really fast?

 

[pooker]

Good points made... it's a fairly large pump, and it pumps up tires pretty fast.
The pump comes with a gauge, and i have a autometer boost gauge aswell.
Both my compressors have broken regulators, and they shoot out at 100 psi, how exactly would i use them? Plug it in and out really fast?

Yes if your using an air compressor once it feels up plug it in until you reach your desired psi by using your aftermarket gauge then unplug and listen for leaks.

 

[PieEyedPiper]

I never pressurize the turbo inlet.
I guess I have a fear of exacerbating potentially leaky seals.

Try testing from the bottom of your intercooler.
Also, you may have to put the car in gear and push it a few inches to properly align valves/pistons etc in the head. If the engine is sitting in just the wrong spot you can't build any pressure no matter what you do.

EDIT: always test with the oil cap off.

 

[sbcxtreme]

Do you have a ball bearing turbo? Hear any bubbling sounds from the oil pan?

 

[eboy0]

I never pressurize the turbo inlet.
I guess I have a fear of exacerbating potentially leaky seals.

Try testing from the bottom of your intercooler.
Also, you may have to put the car in gear and push it a few inches to properly align valves/pistons etc in the head. If the engine is sitting in just the wrong spot you can't build any pressure no matter what you do.

EDIT: always test with the oil cap off.

I tried the pushing of the car, didn't take oil cap off though...
Anyways, i can pressurize the piping from anywhere except the turbo inlet, like, i can take the turbo outlet pipe and pressurize it from there to TB and it'll hold boost.
This isn't normal is it?

Do you have a ball bearing turbo? Hear any bubbling sounds from the oil pan?

Running stock T25 for now, so I wouldn't know the answer, probley not? No bubbling from what i can tell.

 

[90TTalonAWD]

what i would usually do is drive my car over to the gas station and then remove the air filter and use their air pump to pressurize my pipes. It pumps enough air to create boost unless you have a very large leak in which case you should be able to find that first and fix it. Boost leak tests are best for finding small leaks, not large ones that should be apparent anyways.

 

[DSMunknown]

I'm having a problem building boost using one of those homemade testers, it seems to work on the throttle body, but won't work on the turbo inlet anymore... i put it on there and when i pump it w/ my bike pump, the psi just stays at 0, tested pipe by pipe, until i reach the turbo outlet and no leaks, its only when i pump through the turbo inlet where it doesnt' build boost.
Anyone help?

If you have trouble making your own boost leak tester, buy one from MachV.


Also, look through this thread for an alternative to reading the boost pressure when testing.

EDIT: always test with the oil cap off.

Why is that? So the recirculating air out of the valve cover isn't so loud that it potentially drowns out possible air leaks?

Anyways, i can pressurize the piping from anywhere except the turbo inlet, like, i can take the turbo outlet pipe and pressurize it from there to TB and it'll hold boost.
This isn't normal is it?

I'm a bit confused. Do you not wish to put the tester onto the compressor-side housing?

 

[Mytrn2brn]

Hi Guys

So i need to do a boost leak test but i don't have an aftermarket boost gauge. I want to do the test right and not blown up the intake system so i should wait until the boost gauge comes in and gets installed before i do the test right? It's going to take 3-5 days before the gauge arrives should i not drive my car, because that down time simply waiting for a gauge will really bite. I mean the car drives fine as long as i don't try to boost or will I be doing more damage?

Thanks

 

[92eagleTSI]

If you know you have a leak and just need to find it you can just set the regulator on the compressor to like 15psi. Now if you want to monitor how long it holds that boost or how quickly it bleeds off i would just wait for the gauge to come in. I can only guess that your having problems but driving the car depends on how bad it is.

 

[Mytrn2brn]

That the thing, I don't have a compressor I was going to use a bike pump or some kind of air tank. I say i have a leak because my car sputter when I try to boost it and i just put in some new plugs. but will driving my in this state do more damage.

 

[92eagleTSI]

It is possible to do more harm but you will probably be ok as long as you stay out of it. If you have a leak(and it sounds like you could) the air is being measured by the ecu but some of the air isn't going to make it to the engine which means you'll now have too much fuel for the amount of air your getting causing you to run rich. Which can foul your plugs or screw with the readings from your o2 sensors. If your in vacuume alot then you could run too lean because your getting air thats not being metered by the ecu and it's not adding enough fuel. Many would recommend that you just let it sit until you can get it fixed but i would say take a look at the plugs and if they look ok then limp around for a few days.

 

[Mytrn2brn]

Thanks, that sounds like good advice. I'll try not to drive the car as much as I can. I think my plugs are OK I just dropped in a new set last night and i check the gaps today. Anyone know how fast egauges.com can ship a boost gauge.

Thanks again

 

[Mytrn2brn]

Hey guys, I'm in the process of a boost leak test but to get my tester onto the turbo inlet i had to disconnect the intake from the bov where it would recirculate I guess. The test won't work like this will it?

thanx

 

[Mytrn2brn]

Hey guys, I'm in the process of a boost leak test but to get my tester onto the turbo inlet i had to disconnect the intake pipe from the MAS and bov where it would recirculate I guess. The test won't work like this will it?

Thanx