Boost leak
 

Alright, so here's my story. I haven't done a boost leak check on my 2g gst but I know for a fact that I am getting a boost leak from where my uicp hose connects to my smic. I have a custom mbc and wherever I set it, it never goes past 10psi. I'm still running on a stock turbo. I have a hard uicp from buschur racing with the 1g flange for the 1g bov. Sometimes when I'm driving, I hear a high pitched whistle comming from the engine. I finally opened up the hood and found where it had come from which was what I just explained up there at the point where the hose from the uicp connects to the smic. I clean my engine bay atleast once a week and I've noticed that where the hose connects the the uicp, there's some type of black grease that probably sputtered out from the leak.

I'm thinking that maybe if I replaced the current hose to a longer hose that connects the smic and the uicp together, it might solve the problem. That's the only possible solution I can come up with for this problem.

What do you guys think? Give this a try or is there something else that I am not seeing here? Sorry for the long story.

:confused:

Re: Boost leak
 

This is not at all an asshole response, but, do a boost leak test. That is far easier and simpler than trying to diagnois where the leak might possibly be over the internet. You know where one leak is which is great, another place to check is the BOV where it mounts to the flange, did you use a new Mitsu gasket when you installed this? Throttle bodies/TB elbows like to leak to, did you use a new gasket here too?

Another problem might be your homemade MBC, have you tested it and been able to prove it effectively works? ~10 psi is your stock wastegate preasure so its possible your MBC isn't really doing any controlling at all and let letting air past unrestricted to the WG actuator.

Re: Boost leak
 

I know that the MBC works good b/c I gaved it to a buddy of mine to put on his 96 Talon AWD and it worked just fine. He was running on a Big 16g turbo and he set it to where it was boosting to 18psi so I know that it couldn't be the mbc.

As for the gasket, I'm pretty sure it was a new one because it had come in with the bov when I ordered it from Buschur Racing. But like you said, I guess I should just really do a boost leak check but for the high pitched whistling noise that I hear when I'm driving get's really annoying. That was why I figured if I fixed that up first, that stupid noise will go away.

Re: Boost leak
 

The SMIC could be corroded and have holes in it also. That is pretty common. Usually they are on the neck.

Re: Boost leak
 

Yup, if thats the case sand it down and cover the necks in a thin layer of JB Weld.

Re: Boost leak
 

Well, I went out to get a longer hose (7 inch. long actually). Put the whole thing back together and the high pitched noise that was coming out of the hose from the ucip to the smic is now gone. Hopefully forever! My 1g bov sounds a bit louder. I'm going to have to wait till tomorrow to get my custom mbc back from my buddy then I shall see if this fixed the boost leak. If not, then I'm going to make myself a boost leak checker.

Re: Boost leak
 

Another stupid question for you Joker. Do you have an after market boost gauge!

Re: Boost leak
 

Since he's saying "10 psi" I would assume so since the stock 2G boost gauge only reads "+" or "-".


Its still a very good idea to do a boost leak check b/c changes are VERY good you have a least a few other smaller leaks...I haven't seen a DSM tested yet, new or old, that hasn't had some type of leak.

Re: Boost leak
 

Haha, of course I have an aftermarket boost guage.

Re: Boost leak
 

Just do a boost leak test. I'ts so much easier too and That'll save you the hassle of using the process of elimination to figure out where you are leaking.

Re: Boost leak
 

You would not believe how many times I seen this question and they are comparing it to there stock gauge.

Re: Boost leak
 

I'm suprised the stock one on my car is mostly on. When the after market says 12 psi, the stock one will be 14, but works great to see if i'm boosting or not.

Does anyone on here use, or recomend, the soapy water technique? I've heard of others using soapy water on pipes to find the leak. It leaves little bubles coming from the pipe where the air is coming out if you give it some gas.

Re: Boost leak
 

the soapy water technique is by far the best and only real practical tool for finding leaks. Use the Force,er, suds!

Re: Boost leak
 

that'll work, but you can ussuly hear and feel where it is leaking.