Boost Leak/Blown Valve?

[esoung]

The situation is that when I run the car there is no boost, wideband runs all over the place no matter what the setting are on my SAFC and the car died downs while I'm driving anywhere from 20-35 mph.

I definitely have a major boost leak. Using a boost leak tester I cannot put any air pressure in and I cannot find where the boost leak is.

Could it be a blown head gasket or valve? I mean the is no air pressure at the throttle body or does the head gasket or valve have nothing to do with a boost leak test?

 

[#1 laser]

its for sure not the head gasket if your car gets hot than its possible.

 

[#1 laser]

so when u do the boost leak test there is no pressure. if thats the case than u got a major leak some where

 

[tbonitz301]

Did you try testing at the throttle body?

 

[turbotalawd]

If you have a boost leak THAT bad then you should be able to hear where its coming from. Get a spray bottle with some water and spray it across the intercooler piping and the couplers.

 

[esoung]

Did you try testing at the throttle body?

What do you mean testing the throttle body?

 

[esoung]

If you have a boost leak THAT bad then you should be able to hear where its coming from. Get a spray bottle with some water and spray it across the intercooler piping and the couplers.

I tried that but I cannot find any leaks I think it leaking somewhere in the head. I'm not getting any air pressure from the intake manifold/throttle body.

 

[bluetlr2001]

What do you mean testing the throttle body?

Take your boost tester and put it on your throttle body. If you can put pressure in it at the throttle body then your leak is between your turbo and throttle body. But if you still got a leak spray your intake mainfold and injectors down and look for bubbles

 

[esoung]

its for sure not the head gasket if your car gets hot than its possible.

Does the air from the boost test go through the valve and headgasket?

 

[turbotalawd]

Is there anyway you can do a compression test?

 

[esoung]

Is there anyway you can do a compression test?

Yes I can do a compression but it is a possibilty that the boost can leak from the head gasket?

 

[#1 laser]

no boost cant leak from the head gasket

 

[esoung]

So with could be the possibility of a boost if I cannot find the leak and there isn't any air flow before the throttle body?

 

[#1 laser]

try pressure testing from the throttle body then do a full boost leak test do u have the stock intercooler pipes

 

[esoung]

No I don't have stock intercooler pipes. I have a FMIC.

 

[#1 laser]

if your runnig the stock bov it tends to leake on aftermarket ic pipes

 

[#1 laser]

gave you tried to spray water around where your testing to see if it bubbles

 

[zero97tsi]

All you have to do is put your tester on the turbo inlet, or begining of pipes, which ever. pull the piping from the throttle body elbow, and grab something to seal it off (I had a friend hold a rubber block over the end, it worked) and pressurize it with the piping being the only thing tested. If you cant pressurize JUST the pipes, make it smaller, test the FMIC alone, test both sides of the pipe seperately, etc.

If you dont get a leak with the pipes alone, leave them out of the loop and put your boost leak tester directly onto the throttle body elbow, and try from there.

And yes, it can leak into the cylinders, rotate the engine to cyl 1 TDC, and make sure you cap the vacuum lines that go into the intake piping.

 

[esoung]

if your runnig the stock bov it tends to leake on aftermarket ic pipes

Beside aftermarket FMIC pipes I also change the BOV. I fully rebuilt my engine to a stage 4, fuel system, fmic, etc...

 

[tbonitz301]

Did you try the boost leak test at the throttle body? put the engine at 30*ATDC on#1, and pressurize the engine and post back. I might have misunderstood you, but did you say you dont even have pressure at the upper intercooler pipe?

 

[esoung]

Did you try the boost leak test at the throttle body? put the engine at 30*ATDC on#1, and pressurize the engine and post back. I might have misunderstood you, but did you say you dont even have pressure at the upper intercooler pipe?

What's 30*ATDC?

 

[dsmulla]

If I ever you, I would check the BOV if its sealing properly or not? I had that problem with my SSQ where I was getting no pressure at all and I found out that it was my BOV with a major leak.

 

[tbonitz301]

Sorry man. It's 30 degrees after top dead center on number 1 cylinder + 1 on checking the BOV.

 

[esoung]

Did you try the boost leak test at the throttle body? put the engine at 30*ATDC on#1, and pressurize the engine and post back. I might have misunderstood you, but did you say you dont even have pressure at the upper intercooler pipe?

Okay, when I switch from electronic boost control to mbc I double looped the air flow so the wastgate was always open.

Beside that I can hold 15 psi on the boost leak tester. There are some minor leaks but when I start the car it still has no boost and is runs really lean all the time no matter what the SAFC setting are. I figured that if the boost leak is after the MAF at the turbo compressed outlet coupler I wouldn't be lean right?

 

[68442]

Did you figure this out? Mine is doing the same thing with the system not taking pressure and no leaks that I can find. I'm going to try some of the suggestions listed.