I have a pretty severe vaccuum leak at the rear of the intake manifold that I can't seem to find. I've replaced the "Y" pipe clamps sprayed water all over the place hoping to hear a stumble and Nothing. The car boggs down really bad under hard acceleration. I'm thinking the intake gaskets may be leaking. Any one have other ideas on finding this leak? I can hear air "sucking" @ the back of the manifold!!

 

replace the manifold gaskets both sides sometimes they leak, when my motor was the srt6 i changed the gaskets 3 times, I guess after you drive a small Distance then come to a red light, the car feels like it's either going to stall or it does stall,, the gaskets are like 8 to 10 bucks at the dealer. Your toque sequences is the most important, good luck,,,,,,, Jim

 

Have you pulled everything out of the way to get in behind there? There are a few things that it can be...but you need to get in there... hoses, base of the throttle body, and just not getting the hoses and clamps all the way on properly... Water isn't the best to use. I will PM you an old trick I use...

 

Is it a secret?
The old propane gas thing or what?
He's got three posts and we are chopped liver or what?

Maybe you have a thing for sailors.

 

you had better stop while you are ahead....Davey......lol Not recommended for just anyone to try.... some youngster might blow himself up...no propane involved...

 

I've actually removed the "Y" pipe and and everything I could get to without removing the intake and fuel rails. I did notice that my throttle body does not have a gasket. I was a little leary about using anything "flammable" in testing.

 

Not for the faint of heart... lol. It would be hard to tell if the gasket is leaking, just make sure the throttle body is tightened down, and reconnect every hose you see. I have missed getting those hose clamps back on properly many times... you just have to re check each time...

 

There should be a gasket, an O-ring in a groove, no gasket and you will have a leak. Others said they had a flat paper type gasket, but the parts manual shows an O-ring.

 

Dave is right...but it will require you to take the throttle body off, which isn't a bad thing. You can clean all the oil out of it...lol. But it would eliminate one area that could be leaking. I still think you had a hose loose somewhere...good luck. Dave won't steer you wrong...

 

have the same problem, already applied rtv on throttle oring but no luck, hissing is still there...

 

I would suggest using the propane torch trick ( unlit of course ) to find the leak.
( If you are not familiar, with the engine idling, you pass the torch around all the areas where there MIGHT be a leak, if the engine speeds up, you found it ! )

If you are a smoker, it's not a good idea to have a lit one in your mouth during this procedure !

PROCEED WITH CAUTION !!!!
We disclaim any and all liability in case you f**k up .

NOTE: There will always be a certain amount of 'hissing' from the drivers side small tube on the valve cover vent, especially if you have a oil catch can installed. This is normal. Pinch this hose and see if the hissing stops.

If you want to see how the engine reacts from a REAL vacuum leak, unhook the hose from the purge valve mounted on the drivers side fender.
The engine should get really unhappy at idle when you do this.