Ok, let me start from the top. Last night me and a couple buddies turned up my truck, shaved the fuel plate modified the "foot" in the AFC housing and cranked the star wheel. When we were buttoning it back up, the gasket that sits on the grid heater between the heater and the air horn broke, so we put a dab of silicone on the crack and buttoned it up. Truck was fine, then today coming home on the highway, I noticed an "air" noise. I first thought I had the heat on, and I didn't want it on, so I reached for the HVAC controls to shut it off and saw that it was off. Then I gave it some more throttle and the noise got louder as the RPMS climbed. The noise sounds JUST like the heat or air coming through the defrost vent. I thought it was the air horn, so I took it off, and make a brand new gasket with RTV, buttoned it up, waited and hour for the silicone to dry and fired it up. However, still have the same . Where else should I check for boost leaks or what else could be the problem here....?

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Oh, I wanted to add. After I sealed it, the first time I started it, the truck started ok, and then the rpms dropped and it studdered a bit for a few seconds and they came back up and everything seemed to be ok...could that be from teh silicone that ran over the edge getting sucked in...?

 

check all your intercooler hoses probably a clamp off seat or something happens a lot especially since you had the horn off

 

I checked all the boots and cranked down the clamps nice and tight and still have the hiss. Do you think it could be coming from the horn itself? Being that its below freezing and I only let the RTV cure for about an hour before I started and drove it....im not so sure it sealed. Would a leak from the intake horn sound like that?

 

This is a shot in the dark but is your afc line snug on the back of the afc being that you had that off

 

Yes, thats tight too I checked that. Could the hissing just be from the air horn that isnt sealed correctly and if thats the case is it safe to drive with this leak (until the gasket comes early this week).

 

You might have a tear in a boot?

 

I could be wrong but i dont think its the gasket it needs to be there for sure but i dont think a cracked gasket would make it run bad how bout getting some gasket material from parts store and make your own and see if that helps

 

read my first post, it wasn't really running bad. I couldnt really tell if it was any more sluggish than usually, I kinda feel like it was a little different but I think its my head playing games with me once I heard the hissing. I made a gasket with hi temp ultra black rtv but I fired ti up and drove it not 30 minutes after i sealed it so I dont think it set up...would a leaking air horn gasket cause that kind of hiss? i dont have my boost gauge in yet so I dont really have any numbers but i should have it in tomorrow....but when I was coming home after i detected the hiss it wasnt overly smoking or anything out of the usual, seemed to run O.K. Does anyone else have a hiss like this? Like i said sounds just like the heat coming thru the defrost vents.

 

Build one of these: https://www.dieselbombers.com/dodge-...tructions.html if you have a leak it will find it.

 

Thank you VERY much for that post....This is my only form of transportation, so will it do any harm to drive the truck if it does have a boost leak at the air horn or a boost leak somewhere else in the system?