Intake / Boost Leak

[booosting92tsi]

I was driving in the highway the other day, then when i was under boost, I heard a big WHOOOSHHHHHHHHHH! for the engine bay. Then the car won't drive past 40mph, starts bucking.

I opened the hood looked for any intercooler pipes loose or vaccum hoses. Nothing.

I got home , and i performed an intake/boost leak test..... There's definetely a leak near the firewall behind the intake manifold near the drivers side.

WHAT COULD IT BE? What hoses back there are related to vaccum/boost/intake?

When I try to pressurize the system, I hear air leaking from back there, won't even hold any!

 

[oldman]

It's probably the check valve inside the vacuum hose to the brake booster.

 

[booosting92tsi]

It's probably the check valve inside the vacuum hose to the brake booster.

Check Valve? To the brake booster? Can U elaborate more?

Isn't true if the brake booster line is leaking your brakes would act funny as well, I have no problem with braking......

 

[oldman]

Check Valve? To the brake booster? Can U elaborate more?

Isn't true if the brake booster line is leaking your brakes would act funny as well, I have no problem with braking......

The best way to check is to disconnect the hose from IM and plug up the nipple during the pressure test. It can either be the nipple thread, hose or the check valve. I don't know what would happen to the brake system if the check valve is leaking under boost, maybe some one can enlighten us both.

 

[booosting92tsi]

There's difinitely air coming out from under the IM. I can feel it big time. My hands are big, it almost got stuck under there. Anyways, is there any bolts underneath the IM that might 've flown out of there causing a leak. I can't see these damn leak, i can feel it.
What the heck could this be?

Maybe i can have a better view from under the car.......

 

[booosting92tsi]

is it possible that i might have a blown head gasket?

 

[oldman]

There's difinitely air coming out from under the IM. I can feel it big time. My hands are big, it almost got stuck under there. Anyways, is there any bolts underneath the IM that might 've flown out of there causing a leak. I can't see these damn leak, i can feel it.
What the heck could this be?

I thought you said it was behind? If it's from underneth, it's probably the IM gasket or the two vacuum line that runs right under the IM.

is it possible that i might have a blown head gasket?

What was the reason for the leak test? Are you blowing smoke?

 

[booosting92tsi]

I thought you said it was behind? If it's from underneth, it's probably the IM gasket or the two vacuum line that runs right under the IM.


What was the reason for the leak test? Are you blowing smoke?

It's NOT the vaccum hoses in the back of the IM, they were rerouted to the top. The reason for the leak test was to find out where the Intake/boost leak was.....I found it, after i pressurize the system, iT won't hold any pressure , ZERO PSI .

There air gushing out of the IM right underneath it, i can feel it big time with my hands, but i can't see it......... How can the IM gasket blow? is there any other possibility other than the IM gasket?

 

[oldman]

It's NOT the vaccum hoses in the back of the IM, they were rerouted to the top. The reason for the leak test was to find out where the Intake/boost leak was.....I found it, after i pressurize the system, iT won't hold any pressure , ZERO PSI

I can't think of anything else besides the IM gasket, if you have a blown head gasket you should be blowing white smoke with a leak like that. On you next visit with the leak test, open the oil cap and listen for leaks in the crankcase, also pay attention to whether you hear air out of the exhaust.

 

[Xero_Tolerance]

I just did a boost leak test and I found out I have a leak in my IM too. Mine seems to be right around where the coilpack sits but I can't seem to find it. It's not as big as yours though, my car can go up to like 13-14psi at full boost but I get a ton of knock because of the leak I guess. I'm probably just going to buy a new IM since I can't find the damn hole.

 

[98GSX-WI]

Just FYI-- I thought that I had a leak from the IM gasket...but turned out it was the fuel injector seals. If you can feel the air coming out from around the IM...then that's obviously where it's leaking...but just by sound alone...if the injector seals leaking you may not be able to feel the air leaking and you may think it's the IM...

 

[booosting92tsi]

I can't think of anything else besides the IM gasket, if you have a blown head gasket you should be blowing white smoke with a leak like that. On you next visit with the leak test, open the oil cap and listen for leaks in the crankcase, also pay attention to whether you hear air out of the exhaust.

I'm pretty sure the air is leaking from the IM gasket......it might be possible that the bolts are loose? I'm gona try to tighten them and see if it seals the leak! If i can avoid replaccing the gasket, I will. By the way, I removed the AC Compressor, can I also remove the AC Compressor bracket that bolts to the block? Is it dangerous if i remove it?

 

[dsmturbo444]

I had a leak around the IM gasket too, turned out to be the damn coil pack bolt on top of the intake manifold, bolt was missing, and the manifold has a pin hole there, so I RTV sealed a bolt in that hole, and fixed that leak, then found another leak, in the throttle body.




Thanks,Clayton