hissing noise under dash

6point0damn2004 · Jun 7, 2013

Driving around today I noticed a hissing noise that sounded like it was under my dash. Thinking it might be my boost gauge I disconnected that from the elbow. Hiss was still there.It pretty much follows the rpms. The hiss itself kind of sounds like air going through a carburetor when ya have the air cleaNer off.

Got home started looking for soot on the ffirewall thinking it might be an uppie. Didn't see any signs of soot. Did a little internet digging , found a guys description that sounds very similar to mine And he said it ended up being exhaust back pressure sensor tube. From what I can tell that's the tube that goes from the exhaust manifold to up on top of the valve cover and has the sensor up there. Correct?

So any other ideas would be appreciated. Anyone have a part number for that tube off hand?

Thanks in advance

95powerstroke73 · Jun 7, 2013

Had a hissing noise like that with mine, turned out it was only a leaky IC boot on the cold side pipe.
You may have checked and already know its nothing like that, but that's just what happened in my case haha

6point0damn2004 · Jun 7, 2013

I did look at em but I'll have to check em real well

95powerstroke73 · Jun 7, 2013

6point0damn2004 said:
I did look at em but I'll have to check em real well

Worth checking well before digging Into anything haha

When it happened to me it raised with rpm and sounded like it was under the dash even though it really wasn't