So I'm trying to do a boost leak test since my evos not boosting right.

I was doing a WOT pull and ended up hearing a loud pop which I figured was an intercooler pipe, since after that 'pop' the car would just sound loud(turbo spooling) but would not pull.

Looking at the stock MR gauge, when I put air into the system I am only able to get it up to .7 bar, which is roughly 10-11psi. I ended up replacing leaking throttle body shaft seals, but am still only able to pressurize to .07 bar, which takes about 1 minute to get there.

Anyways, when driving the car, in 1-2 I can't really get the car to get pass 0 psi, when shifting into 3rd I'm able to get to .7-.8bar (10-12psi), and if I floor it in 4th, it'll struggle to get pass 1bar(rarely gets pass 1 bar).

I couldn't find anymore leaks doing the boost leak test, the only leak was coming from the actually boost leak tester stem.

I've checked all intercooler pipes, vacuum lines, ix bov, and can not find any cuts or leaks. Am I doing something wrong here? I've searched, and people never really come back to comment on what they did to fix or if they even did fix. My evo was boosting strong all the way to 1.5bar, so something is really off here. I have no checked the wastegate, not really sure how to check it.

 

one of the couplings has a hole in it. for me, it was the one coming off the turbo to the LICP. it's hard to see them if you have the OEM couplings because of the material.

pressurize the system and you will hear the air coming out.

 

That's the beauty of the boost leak test.spray every single coupler or connection with soapy water

 

There may a vacuum line under the throttle body that likely popped off.

You have to McGuyver your arm back there through the strut bar and feel the back side underneath of the TB.

I had this happen on an EVO I was boost leak testing.

 

OP: Did you use soapy water also?

 

Check your LICP hose. You are not building enough pressure to crack the WG open..Check all your hoses as stated aboive spray some soapy water and listen for leaks as well.

 

0.07 Bar is roughly 1 PSIG. Your leak must be huge, and with 1 PSIG youre going to have a hard time bubble checking anything. Either that or you typo'd twice.... did you mean 0.7 Bar ?

 

I had damaged my licp and replaced it with ETS licp just recently before doing the boost leak test, so its not the licp..

I will triple check those vacuum lines (thats the EGR stuff correct?), was pretty sure everything was hooked up.

Yes I used lots of soapy water on all the intercooler piping, injector, bov, bov lines, fmic, throttle body. I was getting some bubbles at the bov, but after taking it off and using hairspray and tightening extra tight the bubbles stopped.. I did not see any other bubbles or hear any sound.

Will triple check this..

Yea, its a typo, I'm only able to pressurize the system to .7 bar, and struggle to even hit 1bar when I'm actually boosting.

Thanks for input guys, would that loud pop I heard when doing a WOT pull be the wastegate by any chance? I have no idea how to check the wastegate..

 

Doesn't seem like its building enough pressure to open the wastegate. I had this same issue and not saying its the same but for me it was my LICP silicone hose. I am low so hit something that knocked it which created a leak.. I would hook up my boost leak tester and try and pressurize the system and it would not hold boost. I would get to about 11lbs and it would not go up any more. Was driving me nuts. After I re installed the LICP hose i was able to test again and it held boost. After 14lbs( i think) i saw the WG open. I could watch it open.. Car was able to build and hold boost. And My problem was solved. Are you logging or do you have a wideband? You should see your AFR's all out of whack when you are driving with a boost leak.

Also are you sure you are testing correctly? How are you hooking up your boost leak tester? When I do mine I unhook the intake and hook mine up directly to the turbo.

 

Yea I hook it up at the turbo inlet just like the guide shows. I was unaware that the waste gate opens when doing a boost leak test. I thought it only opens when the car is actually on. I'll recheck the licp, it's possible the silcone coupler broke free since the tbolt clamps are a really tight fit. I'll be ordering a wideband soon so I can start logging.

 

I had same issue the other day, full throttle pull and pop, hardly any boost and a lot of turbo whistle.

Ended up being a split on the rubber that joints the throttle body. Was underneath it too so extra hard to see. remove and inspect intercooler joints

 

My money is still on a blown coupling.