A Loud "POP" Sound When Intake Mani Gasket Blows?

[98GSX-WI]

Well, as usual--no sooner did I get a new throttle body (58mm) installed and a water injection kit--and I'm driving home--get up to full boost (20psi)--and I hear a loud pop.

When I pull over I hear a loud hissing noise (air leak) coming from under top of intake. (I say air leak, because I don't smell any fuel or anything--which is what I would expect if it was the injector seals). Also, I just had new fuel injector seals installed along with the new TB and new TB gaskets...and now this.

Does anyone know if this loud pop and large hissing leak is symptomatic of the intake mani gasket blowing? I'm thinking that maybe with the new larger TB...that the intake gasket when experiencing the larger airflow for the first time--popped.

What do you guys think? Does this sound like what it would be?

 

[sweet97]

Never heard of an intake many gasket blowing. There is a vacuum line tha runs to your Power brake booster that may have split just enough to cause the pop and leak but not enough to kill ALL vacuum to the booster for the brakes. You can see it from the drivers side and it runs to the brake booster canister. I would check that first. mark
PS: Maybe a TB gasket?

 

[xcelr8n]

Ive never heard a really blown IM before but I suppose it could be that, the only other thing that pops into my head that you didnt mention is the pcv hose, going back into the intake manifold, if that came off it would hiss like crazy and the car would run like total garbage if it ran at all.

 

[95AWD_TSI_TALON]

I have blown my intake manifold gasket quite a few time. Only since I switched to the FRH IM. I have never heard any loud pops or anything during any of those times (also would have been muffled from the external tho). Also 20psi should not have blown it out unless it wasn't torqued down correctly.
Matthew

 

[xcelr8n]

Another thing, do you still have youre BISS screw, I SHOT mine out once on the highway, that sure as hell made a loud pop I'd say, scared my passenger half to death, me to ..
It will make a loud ass hiss to.. check it out.

 

[98GSX-WI]

Another thing, do you still have youre BISS screw, I SHOT mine out once on the highway, that sure as hell made a loud pop I'd say, scared my passenger half to death, me to ..
It will make a loud ass hiss to.. check it out.

Yes, the BISS screw is still there. I took it right back to the shop that installed the TB and WI system. They will be checking it today. The hissing sound is coming from right where the intake mani gasket would be...to far down to feel for air....

 

[L2RTSiAWD]

I don't know about any pop sound but I knew my IM gasket was bad since I did a boost leak test and could feel air blowing on my arm when I stuck it under the IM.

 

[98GSX-WI]

I don't know about any pop sound but I knew my IM gasket was bad since I did a boost leak test and could feel air blowing on my arm when I stuck it under the IM.

I just stopped by the shop...they're going to work on it this afternoon. I would have stuck my arm in there...except the engine was kind-of hot ! I just took it back to the shop before I had a chance to let it cool down and leak test it, etc. The good thing is that I already have a new intake mani gasket...so it shouldn't be down for too long...

 

[98GSX-WI]

Looks like it wasn't the intake manifold after all. As it turns out...two of the fuel injectors "popped" out under 20psi of boost and in doing so--the brand new injector seals ripped/split and are leaking.

The shop said that this has got to be rare and the injectors wouldn't normally pop out under only 20-21psi of boost.

Has this ever happened to anyone else?

 

[sweet97]

The injectors did not "pop" out! properly installed the rail has no movement in it. Most lkely the insulators, the large seal at the bottom of the inj that goes into the head, got torn upon installation as it can be difficult to install the rail and injectors as one unit. I have torn one myself. For my next injector insulator replacement this week I will install the insulators into the head with high temp silicone into the head first and then install the rail/injectors with some of the same silicone on the section of the inj that will contact the insulator as I have had trouble with boost leaks at these insulators even when new installed with a bit of grease on them. Glad you found out the problem and let us know so others can be aware of this potential problem!! Mark

 

[98GSX-WI]

The injectors did not "pop" out! properly installed the rail has no movement in it. Most lkely the insulators, the large seal at the bottom of the inj that goes into the head, got torn upon installation as it can be difficult to install the rail and injectors as one unit. I have torn one myself. For my next injector insulator replacement this week I will install the insulators into the head with high temp silicone into the head first and then install the rail/injectors with some of the same silicone on the section of the inj that will contact the insulator as I have had trouble with boost leaks at these insulators even when new installed with a bit of grease on them. Glad you found out the problem and let us know so others can be aware of this potential problem!! Mark

Thanks for the reply. So I guess the injector seals cound have been ripped during install (the shop did say that they were a very tight fit). Then when under full boost, the injector seal "popped" out from under the injector (and that was the "pop" that I heard).

 

[bullettdsm]

Like sweet97 said, I would suspect install error on that one. For what it's worth, I use a small glob of grease to keep those insulators in place during install.
MB

 

[98GSX-WI]

Like sweet97 said, I would suspect install error on that one. For what it's worth, I use a small glob of grease to keep those insulators in place during install.
MB

Believe it or not--I talked with the guy from Fuel Injector Clinic today and he indicated that the previous seals (black) are known to blow out over about 18psi and the new Viton seals have held up to 40psi.

It kind-of surprised me when he said that, because I would have thought that more people would have had problems if that were true. Take it for what it's worth. He did indicate that it took a long time to get someone to manufacture the Viton seals for him to fit the FIC injectors.