How to tell if you have a boost leak.

[chris@penskeaudi]

What is the best way to tell if you have a boost leak if you dont have a boost gauge.

[bhvrdr]

Originally posted by luvmshavd
What is the best way to tell if you have a boost leak if you dont have a boost gauge.

Inconsistent or lack of power. Limp mode and eventually a CEL. Many times you can hear the leak if it is big enough (sticking head out window). You can also do a pressure test, but that would only be necessary if you are having the above symptoms. cheers! Mike

[chuckdawg82]

i have no idea what a boost leak sounds like. i think i may have a boost leak.

[chris@penskeaudi]

Mike, so if you have a boost leak you should get a CEL,also what the heck does a boost leak sound like

[zemun2]

If it's a big one you will get a CEL, and the leak sounds something like pshhhhhhh...lol

[chris@penskeaudi]

but i have the evo intake so i get that pshhhhhhh anyways lol

[chris@penskeaudi]

hey D, are you running a boost gauge

[bhvrdr]

Originally posted by zemun2
If it's a big one you will get a CEL, and the leak sounds something like pshhhhhhh...lol

hehehe...exactly. cheers! Mike

[chris@penskeaudi]

where are the best places to check for a boost leak.

[Daddy Shroom]

A boost guage would usually help you know, well, that is if you have it installed before hand, then notice a drop in boost.

[bhvrdr]

Originally posted by luvmshavd
where are the best places to check for a boost leak.

The first culprit is usually the 4mm vacuum line that is connected at the intake manifold runner closest to the front of the car. The one people tap into for a boost guage.

The next is the lines and hoses coming off of the BPV area (lower right [passenger] side of the engine compartment).

What are your symptoms?

cheers! Mike

[drew]

Originally posted by bhvrdr
What are your symptoms?

cheers! Mike

lol....

[bhvrdr]

Originally posted by drew
lol....

lol...ok, you got me. Dont I feel like a dork :) cheers! Mike

[chris@penskeaudi]

i just want to check to see if i do. because before i got my new chip it felt like i lost power

[F16HTON]

Boost leaks also tend to be vaccum leaks too. This is not in all cases though. Vaccum leaks are very easy to diagnose. Just tap into any vaccum line and at idle it shoud read 18-22 mmHg.

Some boost leaks will be fine at idle or low boost, then start to leak when boost is bulit up. The best way to check for one is to utilize a VAG-COM and put the car under load in third gear. When you are under boost log the measuring block and graph it in excel. You will notice a sharp dip under pressure that will slowly rise and dip again. (take note: while building boost on third gear you will inevitably surpass the speed limit, so much care has to be taken to get a good log)

You can also spray vaccum lines and boost connectors with strating fluid (ether) and look for an increase in idle. (I do not reccommend this since ether is very flammable)

[chris@penskeaudi]

my buddy works fo a dealer ship i asked him they said the can fog the system to find a leak.

[Daddy Shroom]

Originally posted by luvmshavd
my buddy works fo a dealer ship i asked him they said the can fog the system to find a leak.

::Opens hood and breathes onto his engine bay::

Doesn't work!

[F16HTON]

Originally posted by luvmshavd
my buddy works fo a dealer ship i asked him they said the can fog the system to find a leak.

That is odd, because it is difficult to build boost unless the motor is under load. Maybe they fog the engine on the dyno. If that were the case they could just hook it up to the 1552 scan tool and get a printout of the boost curve.

[chris@penskeaudi]

i will probily just have the hook up the scan tool and check the print out.That just seem easier

[F16HTON]

It will have to be on a dyno if the dealership does it. Doing a log with a VAG-COM is very easy.

[chris@penskeaudi]

If they do it with a vag-com the car has to be on a dyno. Cool free dyno run.

[CO AVANT]

Go to AWE tuning's site, in the FAQ area they have a method for pressure checking the turbo system. You can also do it a cheaper way by using a tennis ball...


Here is a step by step on how I did it:
Take off the big hose that goes out from your air intake into the turbo system. cut a small hole on opposite ends of the tennisball, just big enough to get an air hose blower fitting in it...take the tennis ball and jam it in that hose, then clamp it down air tight. Next, apply 20-30 lbs of air pressure (No more than this) into the tennis ball for short increments of 5-10 seconds on then 5-10 off...do this carefully until the system is charged with air. Make sure you leave the hose fitting air tight on the tennis ball during the whole process so no air gets out that way...listen carefully for leaks, make sure your air compressor is off so you can hear it. If there is a leak you will hear a pssst or "blowing on a grass blade" sound. If the air goes all the way through the system, and you hear a sound where the DV is, then it's just the DV letting out that charged up air flow...try this.

I went through my whole turbo system twice looking for a leak , when I come to find out that a month old OEM 710N DV internal piston had frozen shut...I never checked it until the last straw because I thought there was no way a new unit could crap out that quick. Try these steps first, a boost gauge will help you to see if the actual boost your system is putting out matches what the ECU programming is telling it to put out.

Hope this helps

Peace
Jordan

[chris@penskeaudi]

Thanks Jordan i might try that seems like a pretty easy way to tell.