Hi All, I Have A 03 Evo With 39k on it Well Now i Have a Boost Leak now heres the thing im 100% stock so i make full boost at say 4k rpm but my car NEVER leaks untill im at 5500rpm or more at that point i hear a loud rush of air untill i let out of the gas or shift, i cannot for the life of me find this leak anyone here have any ideas ive done a basic boost leak test cant find anything.


Thanks, Michael

 

How much air pressure are you sending through your system?

 

Ok first of all, have you done a boost leak test before? this leak you hear when you are driving I asume right? well then go to your garage and perform a proper boost leak test with an air compressor, otherwise you will never find a leak, or know if you even have one, with the engine running/driving.
Ed

 

i put about 25psi thru it andyes i hear the noise when driving and when the air noise starts the boost pressure drops about 8lbs and the car falls on its face and stops making power it just started doing this about a month ago.

 

it might be a bov. How many lbs of boost are u seeing?

 

stock 20lbs but when i pressurize the system all the way to 25psi nothing leaks...

 

Check the vacuum lines going to the boost solenoid from the wastegate and turbo compressor, then make sure your stock air snorkel is firmly attached.

 

Check your vac lines, especially the lines around the back of the intake manifold. Also could be the BOV.

 

if u seeing 19-20lbs consistent, there should not be any boost leak then. Sound like a vaccum leak to me

 

You do realize if he has a vacuum leak, he would have a boost leak, right?

 

even with a leak the turbo still makes the same boost pressure, it just has to work harder to do so.

 

correct

 

if you have a stock 8 BOV thats a problem, even if its not the culprit in this instance. I would still upgrade to a ix BOV for 60 bucks give or take its worth it.

 

iam with 20gmr, vacuum leak doesnt affect boost at all.

 

Unless it's in line with the BC/Wastegate ...

If you are 100% stock, your stock boost control solenoid could be sticking for some reason at that point. It's not common, but it could happen. If it sticks open, you would drop to around 11 psi.