I am thinking of making a boost leak tester for my Evo.

Looking at the layout of things / considering ease of applying the tester, I am thinking of making it so that I just replace the air box with my adapter and pressurize the system from there. Can anyone tell me if this would be Ok or is it a bad idea. Pros and cons to it that I can think of are :

Pros:
I just need to remove the Evo's air box and attach my pressure tester
Easy to connect disconnect air box.
Tests whole system.
Doesn't disturb "pressurized side" of intake system so finding and fixing leaks is easier ( compared to if I disturb pressurized side I MAY introduce leaks by loosening tightening hoses etc )

Cons
It might ballon out the rubber pipe that goes from the air box to the turbo.

Applying pressure to the front of the intake impeller could be bad ?? ( Pushes impeller into turbo casing ?? damage bearings ??? )

Anthing else ?

If I didn't apply the pressurized air there the next place I was thinking of was disconnecting the hose from the turbo to the intercooler, but to do this I think I'd need to take of the Evo's undercarriage tray and I'm disturbing connections to boot.

So does anyone know how the pros do it ?

TIA

 

It will do no damage to your turbo, just need to apply 20-30lbs of pressure from an air compressor or use a hand pump as some people do. You can get all the items from a local hardware store or home depot. Consists of a coupler, cap and air connection which is inserted into the cap.
http://www.vfaq.com/mods/ICtester.html http://www.nx2k.com/eclipse/pressuretesterpage.htm

 

Can someone verify whether the car needs to be in TDC or in some special setup before running the test? Will the air go through the intake and out somewhere or through the exhaust?

Thks

 

Dont think it matters , i dont "think" stock cams have overlap . But i made a homemade tester and worked very very good for me , @15 psi i heard a leak that sounded like a whistle , so it werks !

 

The only thing I can think of with your setup is that by pressurizing the intake track like you say,
you may not notice if your BOV leaks at a certain psi because pressure is the same on both sides of the BOV.

I want to make a tester too, but with an aftermarket intake it is easier.
I will remove the intake pipe and clamp the test fitting into the connector hose that goes on the turbo.
That way I will hear if the BOV seat leaks.

 

why not just use the hose to that connects to the BOV and insert the compressor into the hose

 

I have been doing boost leak test that way for years with no problems. I always set the compressor to 30psi and go from there. I have never had any damage related to it. TDC would be ideal but not needed.

*note I meant doing it directly from the inlet of the turbo.

 

Ideally, you'd want to have the engine at top dead center during the test. If your intake valves are open, you'll be pressurizing your combustion chamber also which will result in you pressurizing your crankcase. You might as well do this to eliminate some of the variables.

Also keep in mind that there is no oil pressure going through the turbo's center cartridge w/ the engine off. So air can leak past the compressor blades and into the oil pan.

From my experience, all the major leaks can be audibly detected at about 20 psi.

 

I don't know but I had to set the engine to TDC last time I check. I also had to cap one of the vacuum line on the throttle body, (A) but not sure. . NOt sure if both is require. I also notice air coming out from the throttle body (gasket). The highest psi I could go was 15.

 

i recently have a boost leak on hot day. 21psi--->16psi at 7k rpm...with mbc....
what u think the problem is??
and about home made tester--can i put tester on the turbo inlet hose? not the inlet of turbo? (too much work if i had to put tester into turbo inlet)...
thanks....

 

Try this for a leak checker. It works perfect.


http://www.vfaq.com/mods/ICtester.html

 

someone please help me understand this. Im confused on what is the turbo inlet. Isn't the turbo inlet the part of the turbo that connects to the intake piping?

Why is yesevo saying it would be easier to test from the turbo inlet hose as opposed to the turbo inlet? isn't that the same thing?

 

I made one with a PVC cap and an air hose coupler. I removed my HKS RS and attached it to the turbo inlet. I set my air compressor to 15psi. I never messed with TDC. The little bit that blows by the piston isn't going to stop you from finding intake tract leaks.
My 1st time I heard a major leak at the outlet hose from the turbo. I also found my BOV (TurboXS H34) leaks a bit, and the throttle body, butteryfly shaft leaks a bit at the shaft.
Anyway, it helped alot and was easy and cheap.

 

Great thread!

 

just made one yesterday and pressure tested last night since i have been having a boost leak for a month now...... at first the whining noise was so loud that i couldn't tell where it came from.... it sounded like it was coming from the turbo itself.... so i decided to jack up the car and look at the lower intercooler pipe.... and what do you know..... i just figured it was that since the leak started the day i put on da intercooler.... after i fixed that i pressure tested again and i'm good to go.... just wanted to say how informative these great threads are..... thanks guys