Many of you know by now that I"m very particular about doing boost leaks... I often have a hard time convincing clients and/or the shop mechanic they are using to actually spend a little extra time to check for boost leaks. First of all, most if not all do not even have the tool to do it. Lately I have been getting thru to a couple clients who actually listened to me vs. their installer and did the test properly. Hence, boost leaks found and cars are up and running again...
With that said, many of you think its as easy as going to home depot and getting $17 worth of parts.. in theory yes but honestly spend a few bucks and get it right... you don't want a PVC pipe blowing out in your face and or hitting car when it pops at 20 psi...

Getting the parts and compressor is easy.. diagnosing the problem is another.. getting to it and fixing it is another... you really have to know what goes where and what's the function of the particular part..

So my weekend story start Friday... like any other day a client shows up to do an exhaust... I offer to do a free boost leak test... car is a virgin besides Baley"s Dvs and F hose....

I hook up my tester kit to the compressor side of both turbos... sealed tight and has a valve stem on one of them for the compressor.






Then I proceed to put air in for 15 seconds... let go.. check with a tire gauge and see 10 psi... Ok so I continue to 15and 20 if I'm lucky... 15 seconds later... still 10 or so... Ok I know we have a problem... I get up look inside the engine bay.. spray some soap and water mixed in a Windex bottle... right away I see the Baileys's leak.. after further inspection not only the plastic nipple but also the hex rivets that hold the top of the DVs are leaking... client had them put in recently by a Pro Porsche race team. Here is what I found...



Apparently who ever put them in did not bother to secure the plastic nipple on top tight...


SO I took out the nipple put some teflon tape and secure it... then realized the back one was leaking too... fix it... They forgot to zip tie the hoses and one was leaking at the nipple.. they used a larger ID vacuum hose... fix that...

NEXT:
I go back to putting air in the system via the turbos ... 10 psi again... thats all I can get... figured thats not the only problem... Then I spent 3 hours taking things on and off looking for the other leak... still no go.. problem is I cant see it.. just hear it... no bubbles...
Took off the Y pipe and went after the pressure test at the TB..



you can see the air coming out as I put pressure on the tester.. but that is connected to the TB... the plenum.. and a bunch of lines... thus it could be anything.... cant see it... touch it... just hear it...

So I decide to make a custom tester for the plenum after the TB... this way I can see more.. have access to the top of the motor as well...



Same problem.. but now I can see and touch everything... I put pressure on my funky home made tester and find the air escaping from the bottom of the tester at the junction to the plastic black T plenum.... I unscrew it... and obviously there is a big O ring... the one that usually seals up against the back of the TB...



and the O ring...



Now I'm sure I found the issue.. going to the dealer for the new O ring today... will slap it on and see if it seals... The car is a virgin... never modded.. Now imagine all of you who did a bunch of upgrades like IPd plenums, injectors, hoses and ICs and Y pipes( Oh boy do I have stories on these), etc. and never did the correct boost leak... how sure are you the car is healthy?
A very important observation... although the leak was not apparent at 10 psi... it did show up soon after... thus if you think a " smoke test at 5 PSI " will find your issues think again...
This is dirty work.. most shops would tell you that they will have to drop the motor and get you for thousands of dollars... I had one show up like that.. I found the issues with a soap and water lol
I can go on and on and on.. how I found a OEM wg leaking... catch can check valves, fuel tank vent line check valves... etc...
The thing I can't stand is when a installer is arguing with me that the car has no leaks yet I know it does... I been around this for too long... I sell a tune, exhaust, and turbos to a client and then Im blamed for the car not running right... I get an answer like " we checked all the connections" and everything seems to be fine...
My friends, that's like going to the doctor for an annual check up and not getting a blood test...
I hope I enlightened some of you.. have a great week you all...
https://markskituning.com/pressure-t...d-boost-leaks/

Markski

 

Thank you.

 

Newbees..pay attention... he preaches the gospel...

 

Thank you!!

 

Did it on Thursday last week. Found 3 massive leaks. AfR went from 10.7 to 11.4 after fixing them. Oh and the car feels waaaay more responsive.

Just doooooo it!

 

Do it! I blew off a few small vac hoses when I did mine. These cars are designed for 1bar or lower boost. The way they put some of the hoses on I am amazed they don't blow off at 1/2 bar! Had to zip-tie a handfull of them!

 

yeah like the ones behind the TB on the left side.. or the once to the N75 etc.. its crazy...

 

Great thread! Thanks

 

Is this custom-made boost test kit available for sale? Checking website now...

Nice.. only $59.95... anyway you can add that new custom tester for the plenum after the TB?

New kit?

 

I respect people like you who have time to make the customers feel appreciated, please come over to london and sort my car out

 

Being around turbo cars for 15 years, I always pressure test the system. Mark is right, some people will spend tons of $ and time chasing problems when a simple boost test would have fixed it.

 

Im planning to be there soon with our partner nineexcellence.



I can make them per order...

 

i would more than likely grab one, great tool to have in the garage and a necessity if you are modded.

 

Question, If I had a boost leak would my gage read accurately?? I ask because my gauge is still reading 1.2 bars but my clutch which was slipping at WOT is no longer slipping?!?

 

That's pride in your work... to install an exhaust and spend 3-5 hours diagnosing boost leaks for free, you are a good man and I am sure your clients will not even bother looking anywhere else.